CAP1133-1-AIA-TR - Microchip Technology

SMSC CAP1133 DATASHEET Revision 1.32 (01-05-12)

Datasheet

PRODUCT FEATURES

CAP1133

3 Channel Capacitive Touch Sensor

with 3 LED Drivers

General Description

The CAP1133, which incorporates SMSC’s RightTouch® 1

technology, is a multiple channel Capacitive Touch sensor

with multiple power LED drivers. It contains three (3)

individual capacitive touch sensor inputs with

programmable sensitivity for use in touch sensor

applications. Each sensor input automatically recalibrates

to compensate for gradual environmental changes.

The CAP1133 also contains three (3) LED drivers that offer

full-on / off, variable rate blinking, dimness controls, and

breathing. Each of the LED drivers may be linked to one of

the sensor inputs to be actuated when a touch is detected.

As well, each LED driver may be individually controlled via

a host controller.

The CAP1133 includes Multiple Pattern Touch recognition

that allows the user to select a specific set of buttons to be

touched simultaneously. If this pattern is detected, then a

status bit is set and an interrupt generated.

Additionally, the CAP1133 includes circuitry and support for

enhanced sensor proximity detection.

The CAP1133 offers multiple power states operating at low

quiescent currents. In the Standby state of operation, one

or more capacitive touch sensor inputs are active and all

LEDs may be used.

Deep Sleep is the lowest power state available, drawing

5uA (typical) of current. In this state, no sensor inputs are

active. Communications will wake the device.

Applications

Desktop and Notebook PCs

LCD Monitors

Consumer Electronics

Appliances

Features

Three (3) Capacitive Touch Sensor Inputs

— Programmable sensitivity

— Automatic recalibration

— Individual thresholds for each button

Proximity Detection

Multiple Button Pattern Detection

Calibrates for Parasitic Capacitance

Analog Filtering for System Noise Sources

Press and Hold feature for Volume-like Applications

SMBus / I2C Compliant Communication Interface

Low Power Operation

— 5uA quiescent current in Deep Sleep

— 50uA quiescent current in Standby (1 sensor input

monitored)

— Samples one or more channels in Standby

Three (3) LED Driver Outputs

— Open Drain or Push-Pull

— Programmable blink, breathe, and dimness controls

— Can be linked to Capacitive Touch Sensor inputs

Available in 10-pin 3mm x 3mm RoHS compliant DFN

package

Block Diagram

1. SMSC, the SMSC logo and Right Touch are registered trademarks

and the RightTouch logo is a trademark of S tandard Microsystems

Corporation (“SMSC”).

SMBus

Slave

Protocol

SMCLK

SMDATA

VDD GND

ALERT#

Capaciti ve To uch S ensi ng

Algorithm

CS1 CS2 CS3

LED1

LED Driver, Breathe, and

Dimness control

LED2 LED3

Reel size is 4,000 pieces

This product meets the halogen maximum concentration values per IEC61249-2-21

For RoHS compliance and environmental information, please visit www.smsc.com/rohs

Please contact your SMSC sales representative for additional documentation related to this product

such as application notes, anomaly sheets, and design guidelines.

ORDERING NUMBER PACKAGE FEATURES

CAP1133-1-AIA-TR 10-pin DFN 3mm x 3mm

(Lead-free RoHS compliant) Three capacitive touch sensor inputs,

Three LED drivers, SMBus interface

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 2 SMSC CAP1133

DATASHEET

Circuit diagrams and other informa tion relating to SMSC products are included as a means of illustrating typical applications. Consequently, complete informa tion sufficient for

construction purposes is not necessarily given. Although the information has been checked and is believed to be accurate, no responsibility is assumed for inaccuracies. SMSC

reserves the right to make changes to specifications and product descriptions at any time without notice. Contact your local SMSC sales office to obtain the latest specifications

before placing your product order. The provision of this information does not convey to the purchaser of the described semiconductor devices any licenses under any patent

rights or other intellectual property rights of SMSC or others. All sales are expressly conditional on your agreement to the terms and conditions of the most recently dated

version of SMSC's standard Terms of Sale Agreement dated before the date of your order (the "Terms of Sale Agreement"). The product may contain design defects or errors

known as anomalies which may cause the product's functions to deviate from published specifications. Anomaly sheets are available upon request. SMSC products are not

designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property

damage. Any and all such uses without prior written approval of an Officer of SMSC and further testing and/or modification will be fully at the risk of the customer. Copies of

this document or other SMSC literature, as well as the Terms of Sale Agreement, may be obtained by visiting SMSC’s website at http://www.smsc.com. SMSC is a registered

trademark of Standard Microsystems Corporation (“SMSC”). Product names and company names are the trademarks of their respective holders.

The Microchip name and logo, and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

SMSC DISCLAIMS AND EXCLUDES ANY AND ALL WARRANTIES, INCLUDING WITHOUT LIMITATION ANY AND ALL IMPLIED WARR ANTIES OF ME RCHAN TABILITY,

FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND AGAINST INFRINGEMENT AND THE LIKE, AND ANY AND ALL WARRANTIES ARISING FROM ANY COURSE

OF DEALING OR USAGE OF TRADE. IN NO EVENT SHALL SMSC BE LIABLE FOR ANY DIRECT, INCIDENTAL, INDIRECT, SPECIAL, PUNITIVE, OR CONSEQUENTIAL

DAMAGES; OR FOR LOST DATA, PROFITS, SAVINGS OR REVENUES OF ANY KIND; REGARDLESS OF THE FORM OF ACTION, WHETHER BASED ON CONTRACT;

TORT; NEGLIGENCE OF SMSC OR OTHERS; STRICT LIABILITY; BREACH OF WARRANTY; OR OTHERWISE; WHETHER OR NOT ANY REMEDY OF BUYER IS HELD

TO HAVE FAILED OF ITS ESSENTIAL PURPOSE, AND WHETHER OR NOT S MSC HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

Ordering Information:

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 3 Revision 1.32 (01-05-12)

DATASHEET

Table of Contents

Chapter 1 Pin Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Chapter 2 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Chapter 3 Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.1 Communications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2 System Management Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2.1 SMBus Start Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2.2 SMBus Address and RD / WR Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2.3 SMBus Data Bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.2.4 SMBus ACK and NACK Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.2.5 SMBus Stop Bit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.2.6 SMBus Timeout. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.2.7 SMBus and I2C Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.3 SMBus Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

3.3.1 SMBus Write Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.3.2 SMBus Read Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.3.3 SMBus Send Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.3.4 SMBus Receive Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.4 I2C Protocols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.4.1 Block Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3.4.2 Block Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Chapter 4 General Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.1 Power States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.2 LED Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.2.1 Linking LEDs to Capacitive Touch Sensor Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.3 Capacitive Touch Sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.3.1 Sensing Cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.3.2 Recalibrating Sensor Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.3.3 Proximity Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.3.4 Multiple Touch Pattern Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.3.5 Low Frequency Noise Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.3.6 RF Noise Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.4 ALERT# Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.4.1 Sensor Interrupt Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Chapter 5 Register Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

5.1 Main Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

5.2 Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.2.1 General Status - 02h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.2.2 Sensor Input Status - 03h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

5.2.3 LED Status - 04h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.3 Noise Flag Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

5.4 Sensor Input De lta Co unt Reg i st er s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.5 Sensitivity Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

5.6 Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.6.1 Configuration - 20h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.6.2 Configuration 2 - 44h. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

5.7 Sensor Input Enable Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 4 SMSC CAP1133

DATASHEET

5.8 Sensor Input Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.9 Sensor Input Configuration 2 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.10 Averaging and Sampling Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.11 Calibration Activate Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

5.12 Interrupt Enable Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.13 Repeat Rate Enable Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

5.14 Multiple Touch Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.15 Multiple Touch Pattern Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

5.16 Multiple Touch Pattern Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.17 Recalibration Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.18 Sensor Input Threshold Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

5.19 Sensor Input Noise T hr es ho ld Re gist er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

5.20 Standby Channel Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

5.21 Standby Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

5.22 Standby Sensitivity Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

5.23 Standby Threshold Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

5.24 Sensor Input Base Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

5.25 LED Output Type Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

5.26 Sensor Input LED Linking Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

5.27 LED Polarity Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

5.28 LED Output Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

5.29 Linked LED Transition Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

5.30 LED Mirror Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

5.31 LED Behavior Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

5.32 LED Pulse 1 Period Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

5.33 LED Pulse 2 Period Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

5.34 LED Breathe Period Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5.35 LED Configuration Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

5.36 LED Duty Cycle Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

5.37 LED Direct Ramp Rates Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

5.38 LED Off Delay Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

5.39 Sensor Input Calibration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

5.40 Product ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

5.41 Manufacturer ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

5.42 Revision Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Chapter 6 Package Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

6.1 CAP1133 Package Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

6.2 Package Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Appendix ADevice Delta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

A.1 Delta from CAP1033 to CAP1133 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Chapter 7 Datasheet Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 5 Revision 1.32 (01-05-12)

DATASHEET

List of Figures

Figure 1.1 CAP1133 Pin Diagram (10-Pin DFN). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 3.1 SMBus Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 4.1 System Diagram for CAP1133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 4.2 Sensor Interrupt Behavior - Repeat Rate Enabled. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 4.3 Sensor Interrupt Behavior - No Repeat Rate Enabled. . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 5.1 Pulse 1 Behavior with Non-Inverted Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 5.2 Pulse 1 Behavior with Inverted Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Figure 5.3 Pulse 2 Behavior with Non-Inverted Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Figure 5.4 Pulse 2 Behavior with Inverted Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure 5.5 Breathe Behavior with Non-Inverted Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 5.6 Breathe Behavior with Inverted Polarity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Figure 5.7 Direct Behavior for Non-Inverted Polarity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Figure 5.8 Direct Behavior for Inverted Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Figure 6.1 10-Pin DFN 3mm x 3mm Package Drawings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Figure 6.2 10-Pin DFN 3mm x 3mm Package Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Figure 6.3 10-Pin DFN 3mm x 3mm PCB Footprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Figure 6.4 CAP1133 Package Marking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 6 SMSC CAP1133

DATASHEET

List of Tables

Table 1.1 Pin Description for CAP1133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 1.2 Pin Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Table 2.1 Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table 2.2 Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table 3.1 Protocol Format. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 3.2 Write Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 3.3 Read Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 3.4 Send Byte Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 3.5 Receive Byte Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 3.6 Block Write Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 3.7 Block Read Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 5.1 Register Set in Hexadecimal Order. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Table 5.2 Main Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 5.3 GAIN Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Table 5.4 Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 5.5 Noise Flag Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Table 5.6 Sensor Input Delta Co un t Reg ist er s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 5.7 Sensitivity Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 5.8 DELTA_SENSE Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 5.9 BASE_SHIFT Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Table 5.10 Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 5.11 Sensor Input Enable Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 5.12 Sensor Input Config u ratio n Re gist er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 5.13 MAX_DUR Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 5.14 RPT_RATE Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Table 5.15 Sensor Input Configuration 2 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 5.16 M_PRESS Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 5.17 Averaging and Sampling Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 5.18 AVG Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 5.19 SAMP_TIME Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Table 5.20 CYCLE_TIME Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 5.21 Calibration Activate Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 5.22 Interrupt Enable Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Table 5.23 Repeat Rate Enable Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Table 5.24 Multiple Touch Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 5.25 B_MULT_T Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 5.26 Multiple Touch Pattern Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 5.27 MTP_TH Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Table 5.28 Multiple Touch Pattern Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 5.29 Recalibration Configuration Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 5.30 NEG_DELTA_CNT Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 5.31 CAL_CFG Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 5.32 Sensor Input Threshold Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 5.33 Sensor Input Noise Threshold Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Table 5.34 CSx_BN_TH Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 5.35 Standby Channel Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 5.36 Standby Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Table 5.37 STBY_AVG Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 5.38 STBY_SAMP_TIME Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 5.39 STBY_CY_TIME Bit Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 5.40 Standby Sensitivity Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 5.41 STBY_SENSE Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 7 Revision 1.32 (01-05-12)

DATASHEET

Table 5.42 Standby Threshold Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Table 5.43 Sensor Input Base Count Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Table 5.44 LED Output Type Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 5.45 Sensor Input LED Linking Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Table 5.46 LED Polarity Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Table 5.47 LED Output Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Table 5.48 LED Polarity Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Table 5.49 Linked LED Transition Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Table 5.50 LED Mirror Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 5.51 LED Behavior Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 5.52 LEDx_CTL Bit Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Table 5.53 LED Pulse 1 Period Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 5.54 LED Pulse / Breathe Period Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Table 5.55 LED Pulse 2 Period Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Table 5.56 LED Breathe Period Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Table 5.57 LED Configuration Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Table 5.58 PULSEX_CNT Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Table 5.59 LED Duty Cycle Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Table 5.60 LED Duty Cycle Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table 5.61 LED Direct Ramp Rates Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Table 5.62 Rise / Fall Rate Decode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Table 5.63 LED Off Delay Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Table 5.64 Breathe Off Delay Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Table 5.65 Off Delay Decode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Table 5.66 Sensor Input Calibration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table 5.67 Product ID Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table 5.68 Vendor ID Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table 5.69 Revision Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Table A.1 Register Delta From CAP1033 to CAP1133 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Table 7.1 Customer Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 8 SMSC CAP1133

DATASHEET

Chapter 1 Pin Description

Figure 1.1 CAP1133 Pin Diagram (10-Pin DFN)

Table 1.1 Pin Description for CAP1133

NUMBER PIN NAME PIN FUNCTION PIN TYPE UNUSED

CONNECTION

1ALERT#

Active low alert / interrupt output usable for SMBus a lert OD (5V) Connect to

Ground

Active high alert / interrupt output usable for SMBus

alert DO leave open

2 SMDATA Bi-directional, open-drain SMBu s data - requires pull-up DIOD (5V) n/a

3 SMCLK SMBus clock input - requires pull-up resistor DI (5V)

4 VDD Positive Power supply Power n/a

5LED1

Open drain LED 1 driver (default) OD (5V) Connect to

Ground

Push-pull LED 1 driver DO leave open or

connect to

Ground

6LED2

Open drain LED 2 driver (default) OD (5V) Connect to

Ground

Push-pull LED 2 driver DO leave open or

connect to

Ground

GND

CS2

CS1

CS3

LED1

ALERT#

SMDATA

VDD

SMCLK

LED3

LED2

CAP1133

3mm x 3mm DF N

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 9 Revision 1.32 (01-05-12)

DATASHEET

APPLICATION NOTE: When the ALERT# pin is configured as an active low output, it will be open drain. When it

is configured as an active high output, it will be push-pull.

APPLICATION NOTE: For th e 5V tol erant pins that ha ve a pull-u p re sistor, the pull-up voltage must not exceed 3.6V

when the CAP1133 is unpowered.

The pin types are described in Table 1.2. All pins labeled with (5V) are 5V tolerant.

7LED3

Open drain LED 3 driver (default) OD (5V) Connect to

Ground

Push-pull LED 3 driver DO leave open or

connect to

Ground

8 CS3 Capacitive Touch Sensor Input 3 AIO Connect to

Ground

9 CS2 Capacitive Touch Sensor Input 2 AIO Connect to

Ground

10 CS1 Capacitive Touch Sensor Input 1 AIO Connect to

Ground

Bottom

Pad GND Ground Power n/a

Table 1.2 Pin Types

PIN TYPE DESCRIPTION

Power This pin is used to supply power or ground to the device.

DI Digital Input - This pin is used as a digital input. This pin is 5V tolerant.

AIO Analog Input / Output -This pin is used as an I/O for analog signals.

DIOD Digital Input / Open Drain Output - This pin is used as a digital I/O. When it is used as an

output, it is open drain and requires a pull-up resistor. This pin is 5V tolerant.

OD Open Drain Digital Output - This pin is used as a di gital output. It is ope n dra in and re qui res

a pull-up resistor. This pin is 5V tolerant.

DO Push-pull Digital Output - This pin is used as a digital output and can sink and source

current.

DIO Push-pull Digital Input / Output - This pin is used as an I/O for digital signals.

Table 1.1 Pin Description for CAP1133 (continued)

NUMBER PIN NAME PIN FUNCTION PIN TYPE UNUSED

CONNECTION

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 10 SMSC CAP1133

DATASHEET

Chapter 2 Electrical Specifications

Note 2.1 Stresses abo ve those listed could cau se permanent damage to the d evice. This is a stress

rating only and functional operation of the device at any other condition above those

indicated in the operation sections of this specification is not implied.

Note 2.2 For the 5V tolerant pins that have a pull-up resistor, the voltage difference between

V5VT_PIN and VDD must never exceed 3.6V.

Note 2.3 The Package Power Dissipation specification assumes a recommended thermal via design

consisting of a 2x2 matrix of 0.3mm (12mil) vias at 1.0mm pitch connected to the ground

plane with a 1.6 x 2.3mm thermal landing.

Table 2.1 Absolute Maximum Ratings

Voltage on 5V tolerant pins (V5VT_PIN) -0.3 to 5.5 V

Voltage on 5V tolerant pins (|V5VT_PIN - VDD|) Note 2.2 0 to 3.6 V

Voltage on VDD pin -0.3 to 4 V

Voltage on any other pin to GND -0.3 to VDD + 0.3 V

Package Power Dissipation up to TA = 85°C for 10 pin DFN

(see Note 2.3)0.7 W

Junction to Ambient (θJA) 77.7 °C/W

Operating Ambient Temperature Range -40 to 125 °C

Storage Temperature Range -55 to 150 °C

ESD Rating, All Pins, HBM 8000 V

Table 2.2 Electrical Specifications

VDD = 3V to 3.6V, TA = 0°C to 85°C, all Typical values at TA = 27°C unless otherwise noted.

CHARACTERISTIC SYMBOL MIN TYP MAX UNIT CONDITIONS

DC Power

Supply Voltage VDD 3.0 3.3 3.6 V

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 11 Revision 1.32 (01-05-12)

DATASHEET

Supply Current

ISTBY 120 170 uA

Standby state active

1 sensor input monitored

No LEDs active

Default conditions (8 avg, 70ms

cycle time)

ISTBY 50 uA Standby state active

1 sensor input monitored

No LEDs active

1 avg, 140ms cycle time,

IDSLEEP 515uA

Deep Sleep state active

LEDs at 100% or 0% Duty Cycle

No communications

TA < 40°C

3.135 < VDD < 3.465V

IDD 500 600 uA Capacitive Sensing Active

No LEDs active

Capacitive Touch Sensor Inputs

Maximum Base

Capacitance CBASE 50 pF Pad untouched

Minimum Detectable

Capacitive Shift ΔCTOUCH 20 fF Pad touched - default condition s

(1 avg, 35ms cycle time, 1x

sensitivity)

Recommended Cap

Shift ΔCTOUCH 0.1 2 pF Pad touched - Not tested

Power Supply

Rejection PSR ±3 ±10 counts

/ V

Untouched Current Counts

Base Capacitance 5pF - 50pF

Maximum sensitivity

Negative Delta Counts disabled

All other parameters default

Timing

Time t o

communications

ready tCOMM_DLY 15 ms

Time to first

conversion ready tCONV_DLY 170 200 ms

LED Drivers

Duty Cycle DUTYLED 0 100 % Programmable

Drive Frequency fLED 2kHz

Sinking Current ISINK 24 mA VOL = 0.4

Sourcing Current ISOURCE 24 mA VOH = VDD - 0.4

Table 2.2 Electrical Specifications (continued)

VDD = 3V to 3.6V, TA = 0°C to 85°C, all Typical values at TA = 27°C unless otherwise noted.

CHARACTERISTIC SYMBOL MIN TYP MAX UNIT CONDITIONS

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 12 SMSC CAP1133

DATASHEET

Note 2.4 The ALERT pin will not glitch high or low at power up if connected to VDD or another

voltage.

Leakage Current ILEAK ±5 uA powered or unpowered

TA < 85°C

pull-up voltage < 3.6V if

unpowered

I/O Pins

Output Low Voltage VOL 0.4 V ISINK_IO = 8mA

Output High Voltage VOH VDD -

0.4 VI

SOURCE_IO = 8mA

Input High Voltage VIH 2.0 V

Input Low Voltage VIL 0.8 V

Leakage Current ILEAK ±5 uA powered or unpowered

TA < 85°C

pull-up voltage < 3.6V if

unpowered

SMBus Timing

Input Capacitance CIN 5pF

Clock Frequency fSMB 10 400 kHz

Spike Suppression tSP 50 ns

Bus Free Time Stop

to Start tBUF 1.3 us

Start Setup Time tSU:STA 0.6 us

Start Hold Time tHD:STA 0.6 us

Stop Setup Time tSU:STO 0.6 us

Data Hold Time tHD:DAT 0 us When transmitting to the master

Data Hold Time tHD:DAT 0.3 us When receiving from the master

Data Setup Time tSU:DAT 0.6 us

Clock Low Period tLOW 1.3 us

Clock High Period tHIGH 0.6 us

Clock / Data Fall

Time tFALL 300 ns Min = 20+0.1CLOAD ns

Clock / Data Rise

Time tRISE 300 ns Min = 20+0.1CLOAD ns

Capacitive Load CLOAD 400 pF per bus line

Table 2.2 Electrical Specifications (continued)

VDD = 3V to 3.6V, TA = 0°C to 85°C, all Typical values at TA = 27°C unless otherwise noted.

CHARACTERISTIC SYMBOL MIN TYP MAX UNIT CONDITIONS

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 13 Revision 1.32 (01-05-12)

DATASHEET

Note 2.5 The SMCLK and SMDATA pins will not glitch low at power up if connected to VDD or

another voltage.

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 14 SMSC CAP1133

DATASHEET

Chapter 3 Communications

3.1 Communications

The CAP1133 communicates using the SMBus or I2C protocol.

The CAP1133 supports the following protocols: Se nd Byte, Receive Byte, Read Byte, Write Byte, Read

Block, and Write Block. In addition, the device supports I2C formatting for block read and block write

protocols.

3.2 System Management Bus

The CAP1133 communicates with a host controller, such as an SMSC SIO, through the SMBus. The

SMBus is a two-wire serial communication protocol between a computer host and its peripheral

devices. A detailed timi ng diagram is shown in Figure 3.1. Stretching of the SMCLK sign al is supported;

however, the CAP1133 will not stretch the clock signal.

3.2.1 SMBus Start Bit

The SMBus Start bit is defined as a transition of the SMBus Data line from a logic ‘1’ state to a logic

‘0’ state while the SMBus Clock line is in a logic ‘1’ state.

3.2.2 SMBus Address and RD / WR Bit

The SMBus Address Byte consists of the 7-bit client address followed by the RD / WR indicator bit. If

this RD / WR bit is a logic ‘0’, then the SMBus Ho st is writing data to the client device. If this RD / WR

bit is a logic ‘1’, then the SMBus Host is reading data from the client device.

The CAP1133 responds to SMBus address 0101_000(r/w).

3.2.3 SMBus Data Bytes

All SMBus Data bytes are sent most significant bit first and composed of 8-bits of information.

Figure 3.1 SMBus Timing Diagram

SMDATA

SMCLK

TLOW

TRISE

THIGH

TFALL

TBUF

THD:STA

PSS - Start Condition P - Stop Condition

THD:DAT TSU:DAT TSU:STA

THD:STA

TSU:STO

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3.2.4 SMBus ACK and NACK Bits

The SMBus client will acknowledge all data bytes that it receives. This is done by the client device

pulling the SMBus Data line low after the 8th bit of each byte that is transmitted. This applies to both

the Write Byte and Block Write protocols.

The Host will NACK (not acknowledge) the last data byte to be received from the client by holding the

SMBus data line high after the 8th data bit has been sent. For the Block Read protocol, the Host will

ACK each data byte that it receives except the last data byte.

3.2.5 SMBus Stop Bit

The SMBus Stop bit is defined as a transition of the SMBus Data line from a logic ‘0’ state to a logic

‘1’ state while the SMBus clock line is in a logi c ‘1’ state. When the CAP1133 detects an SMBus Stop

bit and it has been communicating with the SMBus protocol, it will reset its client i nterface and prepare

to receive further communications.

3.2.6 SMBus Timeout

The CAP1133 includes a n SMBus timeout fea ture. Following a 30ms peri od of inactivity on the SMBus

where the SMCLK pin is held low, the device will timeout and reset the SMBus interface.

The timeout function defaults to disabled. It can be enabled by setting the TIMEOUT bit in the

Configuration register (see Section 5.6, "Configuration Registers").

3.2.7 SMBus and I2C Compatibility

The major differences between SMBus and I2C devices are highlighted here. For more information,

refer to the SMBus 2.0 and I2C specifications. For information on using the CAP1133 in an I2C system,

refer to SMSC AN 14.0 SMSC Dedicated Slave Devices in I2C Systems.

1. CAP1133 supports I2C fast mode at 400kHz. This covers the SMBus max time of 100kHz.

2. Minimum frequency for SMBus communications is 10kHz.

3. The SMBus client protocol will reset if the clock is held at a logic ‘0’ for longer than 30ms. This

timeout functionality is disabled by default in the CAP1133 and can be enabled by writing to the

TIMEOUT bit. I2C does not have a timeout.

4. The SMBus client protocol will reset if both the clock and da ta lines are held at a logic ‘1’ for longer

than 200µs (idle condition). T his fun ction is disab led by defa ult in th e CAP1133 and can b e enabl ed

by writing to the TIMEOUT bit. I2C does not have an idle condition.

5. I2C devices do not suppo rt the Ale rt Respon se Addre ss functionality (wh ich is op ti onal for SMBus).

6. I2C devices support block read and write differently. I2C protocol allows for unlimited number of

bytes to be sent in either direction. The SMBus protocol requires that an additional data byte

indicating number of bytes to read / write is transmitted. The CAP1133 supports I2C formatting only.

3.3 SMBus Protocols

The CAP1133 is SMBus 2.0 compatible and supports Write Byte, Read Byte, Send Byte, and Receive

Byte as valid protocols as shown below.

All of the below protocols use the convention in Table 3.1.

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3.3.1 SMBus Write Byte

The Write Byte is used to write one byte of data to a specific register as shown in Table 3.2.

3.3.2 SMBus Read Byte

The Read Byte protocol is used to read one byte of data from the registers as shown in Table 3.3.

3.3.3 SMBus Send Byte

The Send Byte protocol is used to set the internal address register pointer to the correct address

location. No data is transferred during the Send Byte protocol as shown in Table 3.4.

APPLICATION NOTE: The Send Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).

3.3.4 SMBus Receive Byte

The Receive Byte protocol is used to read data from a register when the internal register address

pointer is known to be at the right loca tion (e.g., set via Send Byte). This is used for con secutive reads

of the same register as shown in Table 3.5.

APPLICATION NOTE: The Receive Byte protocol is not functional in Deep Sleep (i.e., DSLEEP bit is set).

Table 3.1 Protocol Format

DATA SENT

TO DEVICE DAT A SENT TO

THE HOST

Data sent Data sent

Table 3.2 Writ e By te Prot oc ol

START SLAVE

ADDRESS WR ACK REGISTER

ADDRESS ACK REGISTER

DATA ACK STOP

1 ->0 0101_000 0 0 XXh 0 XXh 0 0 -> 1

Table 3.3 Read Byte Protocol

START SLAVE

ADDRESS WR ACK REGISTER

ADDRESS ACK START CLIENT

ADDRESS RD ACK REGISTER

DATA NACK STOP

1->0 0101_000 0 0 XXh 0 1 ->0 0101_000 1 0 XXh 1 0 -> 1

Table 3.4 Send Byte Protocol

START SLAVE

ADDRESS WR ACK REGISTER

ADDRESS ACK STOP

1 -> 0 0101_000 0 0 XXh 0 0 -> 1

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3.4 I2C Protocols

The CAP1133 supports I2C Block Write and Block Read.

The protocols listed below use the convention in Table 3.1.

3.4.1 Block Write

The Block Write is used to write multiple data bytes to a group of contiguous registers as shown in

Table 3.6.

APPLICATION NOTE: When using the Block Write protocol, the internal address pointer will be automatically

incremented after every data byte is received. It will wrap from FFh to 00h.

3.4.2 Block Read

The Block Read is used to read multiple data bytes from a group of contiguous registers as shown in

Table 3.7.

APPLICATION NOTE: When using the Block Read protocol, the internal address pointer will be automatically

incremented after every data byte is received. It will wrap from FFh to 00h.

Table 3.5 Receive Byte Protocol

START SLAVE

ADDRESS RD ACK REGISTER DATA NACK STOP

1 -> 0 0101_000 1 0 XXh 1 0 -> 1

Table 3.6 Block Write Protocol

START SLAVE

ADDRESS WR ACK REGISTER

ADDRESS ACK REGISTER

DATA ACK

1 ->0 0101_000 0 0 XXh 0 XXh 0

DATA ACK REGISTER

DATA ACK . . . REGISTER

DATA ACK STOP

XXh 0 XXh 0 . . . XXh 0 0 -> 1

Table 3.7 Block Read Protocol

START SLAVE

ADDRESS WR ACK REGISTER

ADDRESS ACK START SLAVE

ADDRESS RD ACK REGISTER

DATA

1->0 0101_000 0 0 XXh 0 1 ->0 0101_000 1 0 XXh

ACK REGISTER

DATA ACK REGISTER

DATA ACK . . . REGISTER

DATA NACK STOP

0 XXh 0 XXh 0 XXh 0 . . . XXh 1 0 -> 1

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Chapter 4 General Description

The CAP1133 is a multiple channel Capacitive Touch sensor with multiple power LED drivers. It

contains three (3) individual capacitive touch sensor inputs with programmable sensitivity for use in

touch sensor applications. Each sensor input automatically recalibrates to compensate for gradual

environmental changes.

The CAP1133 also contains three (3) low side (or push-pull) LED drivers that offer full-on / off, variable

rate blinking, dimness controls, and breathing. Each of the LED drivers may be linked to one of the

sensor inputs to be actuated when a touch is detected. As well, each LED driver may be individually

controlled via a host controller.

The CAP1133 offers multiple power states. It operates at the lowest quiescent current during its Deep

Sleep state. In the low power Standby state, it can monitor one or more channels and respond to

communications normally.

The device communicates with a host controller using SMBus / I2C. The host controller may poll the

device for updated information at an y time or it may configure the device to flag an interrupt whenever

a touch is detected on any sensor pad.

A typical system diagram is shown in Figure 4.1.

Figure 4.1 System Diagram for CAP1133

CAP1133

LED3

SMDATA

SMCLK

Em be dded C ontroller

VDD

ALERT#

LED2

LED1

CS3

CS2

CS1

Touch

Button

Touch

Button

Touch

Button

3.3V – 5V

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4.1 Power States

The CAP1133 has three operating states depending on the status of the STBY and DSLEEP bits.

When the device transitions b etween power states, previously detected touc hes (for inactive channels)

are cleared and the status bits reset.

1. Fully Active - The device is fully active. It is monitoring all active capacitive sensor inputs and

driving all LED channels as defined.

2. Standby - The device is in a low er power state. It will measure a programmable number of channels

using the Standby Configuration controls (see Section 5.20 through Section 5.22). Interrupts will still

be generated based on the active channels. The device will still respond to communications

normally and can be returned to the Fully Active state of operation by clearing the STBY bit.

3. Deep Sleep - The device is in its lowest power state. It is not monitoring any capacitive sensor

inputs and not driving any LEDs. All LEDs will be driven to their programmed non-actuated state

and no PWM operati ons will be done. While in Deep Sleep, the device can be awakened by SMBus

communications targeting the device. This will not cause the DSLEEP to be cleared so the device

will return to Deep Sleep once all communications have stopped.

APPLICATION NOTE: In the Deep Sleep state, the LED output will be either high or low and will not be PWM’d at

the min or max duty cycle.

4.2 LED Drivers

The CAP1133 contains three (3) LED drivers. Each LED driver can be linked to its respective

capacitive touch sensor input or it can be controlled by the host. Each LED driver can be configured

to operate in one of the following modes with either push-pull or open drain drive.

1. Direct - The LED is configured to be on or off when the corresponding input stimulus is on or off

(or inverted). The brightness of the LED can be programmed from full off to full on (default).

Additionally, the LED contains controls to individua lly configure ramping on, off, and turn-off delay.

2. Pulse 1 - The LED is configured to “Pulse” (transition ON-OFF-ON) a programmable number of

times with programmable rate and min / max brightness. This behavior may be actuated when a

press is detected or when a release is detected.

3. Pulse 2 - The LED is configured to “Pulse” while actuated and then “Pulse” a programmable

number of times with programmable rate and min / max brightness when the sensor pad is

released.

4. Breathe - The LED is configured to transition continuously ON-OFF-ON (i.e. to “Breathe”) with a

programmable rate and min / max brightness.

When an LED is not linked to a sensor and is actuated by the host, there’s an option to assert the

ALERT# pin when the initiated LED behavior has completed.

4.2.1 Linking LEDs to Capacitive Touch Sensor Inputs

All LEDs can be linked to the corresponding capacitive touch sensor input so that when the sensor

input detects a touch, the corresponding LED will be actuated at one of the programmed responses.

4.3 Capacitive Touch Sensing

The CAP1133 contains three (3) independent capacitive touch sensor inputs. Each sensor input has

dynamic range to detect a change of capacitance due to a touch. Additionally, each sensor input can

be configured to be automatically and routinely re-calibrated.

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4.3.1 Sensing Cycle

Each capacitive touch sensor input has controls to be activated and included in the sensing cycle.

When the device is active, it automatically initiates a sensing cycle and repeats the cycle every time

it finishes. The cycle polls through each active sensor input starting with CS1 and extending through

CS3. As each capacitive touch sensor input is polled, its measurement is compared against a baseline

“Not Touched” measurement. If the delta measurement is large enough, a touch is detected and an

interrupt is generated.

The sensing cycle time is programmable (see Section 5.10, "Averaging and Sampling Configuration

4.3.2 Recalibrating Sensor Inputs

There are various options for recalibratin g the capacitive touch sensor inputs. Recalibrati on re-sets the

Base Count Registers (Section 5.24, "Sensor Input Base Count Registers") which contain the “not

touched” values used for touch detection comparisons.

APPLICATION NOTE: The device will recalibrate all sensor inputs that were disabled when it transitions from

Standby. Likewise, the device will recalibrate all sensor inputs when waking out of Deep

Sleep.

4.3.2.1 Manual Recalibration

The Calibration Activate Registers (Section 5.11, "Calibration Activate Register") force recalibration of

selected sensor inputs. When a bit is set, the corresponding capacitive touch sensor input will be

recalibrated (both analog and digital). The bit is automatically cleared once the recalibration routine

has finished.

Note: During this recalibration routine, the sensor inputs will not detect a press for up to 200ms and

the Sensor Base Count Register values will be invalid. In addition, any press on the

corresponding sensor pads will invalidate the recalibration.

4.3.2.2 Automatic Recalibration

Each sensor input is regularly recalibrated at a programmable rate (see Section 5.17, "Recalibration

Configuration Register"). By default, the recalibration routine stores the average 64 previous

measurements and periodically u pdates the base “not touched” setting for the capacitive touch sensor

input.

Note: Automatic recalibration only works when the delta count is below the active sensor input

threshold. It is disabled when a touch is detected.

4.3.2.3 Negative Delta Count Recalibration

It is possible that the device loses sensitivity to a touch. This may happen as a result of a noisy

environment, an accidental recalibration during a touch, or other environmental changes. When this

occurs, the base untouched sensor input may generate negative delta count values. The

NEG_DELTA_CNT bits (see Section 5.17, "Recalibration Configuration Register") can be set to force

a recalibration after a specified number of consecutive negative delta readings.

Note: During this recalibration, the device will not respond to touches.

4.3.2.4 Delayed Recalibration

It is possible that a “stuck button” occurs when some thing is placed on a button wh ich causes a touch

to be detected for a long period. By setting the MAX_DUR_EN bit (see Section 5.6, "Configuration

Registers"), a recalibration can be forced when a touch is held on a button for longer than the dura tion

specified in the MAX_DUR bits (see Section 5.8, "Sensor Input Configuration Register").

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Note: Delayed recalibration only works when the delta count is above the active sensor input

threshold. If enabled, it is invoked when a sensor pad touch is held longer th an the MAX_DUR

bit setting.

4.3.3 Proximity Detection

Each sensor input can be configured to detect changes in capacitance due to proximity of a touch.

This circuitry detects the change of capacitance that is generated as an object approaches, but does

not physically touch, the enabled sensor pad(s). When a sensor input is selected to perform proximity

detection, it will be sampled from 1x to 128x per sampling cycle. The larger the number of samples

that are taken, the greater the range of proximity detection is available at the cost of an increased

overall sampling time.

4.3.4 Multiple Touch Pattern Detection

The multiple touch pattern (MTP) detection circuitry can be used to detect lid closure or other similar

events. An event can be flagged based on either a minimum number of sensor inputs or on specific

sensor inputs simultaneously exceeding an MTP threshold or having their Noise Flag Status Register

bits set. An interrupt can also be generated. During an MTP event, all touches are blocked (see

Section 5.15, "Multiple Touch Pattern Configuration Register").

4.3.5 Low Frequency Noise Detection

Each sensor input has an EMI noise detector th at will sense if low frequency noise is injected onto the

input with sufficient power to corrupt the readings. If this occurs, the device will reject the corrupted

sample and set the corresponding bit in the Noise Status register to a logic ‘1’.

4.3.6 RF Noise Detection

Each sensor input contains an integrated RF noise detector. This block will detect injected RF noise

on the CS pin. The detector threshold is dependent upon the noise frequency. If RF noise is detected

on a CS line, that sample is removed and not compared against the threshold.

4.4 ALERT# Pin

The ALERT# pin is an active low (or active high when configured) output that is driven when an

interrupt event is detected.

Whenever an interrupt is generated, the INT bit (see Section 5.1, "Main Control Register") is set. The

ALERT# pin is cleared when the INT bit is cleared by the user. Addi tionally, when the INT bit is cleared

by the user, status bits are only cleared if no touch is detected.

4.4.1 Sensor Interrupt Behavior

The sensor interrupts are generated in one of two ways:

1. An interrupt is generated when a touch is detected and, as a user selectable option, when a release

is detected (by default - see Section 5.6). See Figure 4.3.

2. If the repeat rate is enabled then, so long as the touch is held, another interrupt will be generated

based on the programmed repeat rate (see Figure 4.2).

When the repeat rate is enabled , the device u ses an additi onal control called MPRESS tha t dete rmi nes

whether a touch is flagged as a simple “touch” or a “press and hold”. The MPRESS[3:0] bits set a

minimum press timer. When the button is touched, the timer begins. If the sensor pad is released

before the minimum press timer expires, it is flagged as a touch and an interrupt is generated upon

release. If the sensor input detects a touch for longer than this timer value, it is flagged as a “press

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and hold” event. So long as the touch is held, interrupts will be generated at the programmed repeat

rate and upon release (if enabled).

APPLICATION NOTE: Figure 4.2 and Figure 4.3 show default operation which is to generate an interrupt upon

sensor pad release and an active-low ALERT# pin.

APPLICATION NOTE: The host may need to poll the device twice to determine that a release has been detected.

Figure 4.2 Sensor Interrupt Behavior - Repeat Rate Enabled

Figure 4.3 Sensor Interrupt Behavior - No Repeat Rate Enabled

Touch Detected

INT bit

Button Status

Write to INT bit

Polling Cycle

(35ms)

Min Press Setting

(280ms)

Interrupt on

Touch

Button Repeat Rate

(175ms) Button Repeat Rate

(175ms)

Interrupt on

Release

(optional)

ALERT# pin

(active low)

Touch Detected

INT bit

Button Status

Write to INT bit

Polling Cycl e

(35ms)

Interrupt on

Touch Interrupt on

Release

(optional)

ALERT# pin

(active low)

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Chapter 5 Register Description

The registers shown in Table 5.1 are accessible through the communications protocol. An entry of ‘-’

indicates that the bit is not used and will always read ‘0’.

Table 5.1 Register Set in Hexadecimal Order

ADDRESS R/W REGISTER NAME FUNCTION DEFAULT

VALUE PAGE

00h R/W Main Control Controls general power states and

power dissipation 00h Page 26

02h R General Status Stores general status bits 00h Page 27

03h R Sensor Input Status Returns the state of the sampled

capacitive touch sensor inputs 00h Page 27

04h R LED Status Stores status bits for LEDs 00h Page 27

0Ah R Noise Flag Status Stores the noise flags for sensor

inputs 00h Page 28

10h R Sensor Input 1 Delta

Count Stores the delta count for CS1 00h Page 29

11h R Sensor Input 2 Delta

Count Stores the delta count for CS2 00h Page 29

12h R Sensor Input 3 Delta

Count Stores the delta count for CS3 00h Page 29

1Fh R/W Sensitivity Control Controls the sensitivity of the

threshold and delta counts and data

scaling of the base counts 2Fh Page 29

20h R/W Configuration Controls general functionality 20h Page 31

21h R/W Sensor Input Enable Controls whether the capacitive

touch sensor inputs are sampled 07h Page 32

22h R/W Sensor Input

Configuration Controls max duration and auto-

repeat delay for sensor inputs

operating in the full power state A4h Page 33

23h R/W Sensor Input

Configuration 2 Controls the MPRESS controls for all

sensor inputs 07h Page 35

24h R/W Averaging and

Sampling Config Controls averaging and sampling

window 39h Page 36

26h R/W Calibration Activate Forces re-calibration for capacitive

touch sensor inputs 00h Page 37

27h R/W Interrupt Enable Enables Interrupts associated with

capacitive touch sensor inputs 07h Page 38

28h R/W Repeat Rate Enable Enables repeat rate for all sensor

inputs 07h Page 38

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2Ah R/W Multiple Touch

Configuration Determines the number of

simultaneous touches to flag a

multiple touch condition 80h Page 39

2Bh R/W Mu ltiple Touch Pattern

Configuration Determines the multiple touch

pattern (MTP) configuration 00h Page 39

2Dh R/W Multiple Touch Pattern Determines the pattern or number of

sensor inputs used by the MTP

circuitry 07h Page 41

2Fh R/W Recalibration

Configuration Determines re-calibration timin g and

sampling window 8Ah Page 41

30h R/W Sensor Input 1

Threshold Stores the delta count threshold to

determine a touch for Capacitive

Touch Sensor Input 1 40h Page 43

31h R/W Sensor Input 2

Threshold Stores the delta count threshold to

determine a touch for Capacitive

Touch Sensor Input 2 40h Page 43

32h R/W Sensor Input 3

Threshold Stores the delta count threshold to

determine a touch for Capacitive

Touch Sensor Input 3 40h Page 43

38h R/W Sensor Input Noise

Threshold Stores controls for selecting the

noise threshold for al l sensor inputs 01h Page 43

Standby Configuration Registers

40h R/W Standby Channel Controls which sensor inputs are

enabled while in standby 00h Page 44

41h R/W Standby Configuration Controls averaging and cycle time

while in standby 39h Page 44

42h R/W Standby Sensitivity Controls sensitivity settings used

while in standby 02h Page 46

43h R/W Standby Threshold Stores the touch detection threshold

for active sensor inputs in standby 40h Page 47

44h R/W Configuration 2 Stores additional configuration

controls for the device 40h Page 31

Base Count Registers

50h R Sensor Input 1 Base

Count Store s the reference count value for

sensor input 1 C8h Page 47

51h R Sensor Input 2 Base

Count Store s the reference count value for

sensor input 2 C8h Page 47

52h R Sensor Input 3 Base

Count Store s the reference count value for

sensor input 3 C8h Page 47

LED Controls

71h R/W LED Output Type Controls the output type for the LED

outputs 00h Page 48

Table 5.1 Register Set in Hexadecim al Order (continued)

ADDRESS R/W REGISTER NAME FUNCTION DEFAULT

VALUE PAGE

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72h R/W Sensor Input LED

Linking Controls linking of sensor inputs to

LED channels 00h Page 48

73h R/W LED Polarity Controls the output polarity of LEDs 00h Page 49

74h R/W LED Output Control Controls the output state of the LEDs 00h Page 50

77h R/W LED Linked Transition

Control Controls the transition when LEDs

are linked to CS channels 00h Page 51

79h R/W LED Mirror Control Controls the mirroring of duty cycles

for the LEDs 00h Page 52

81h R/W LED Behavior 1 Controls the behavior and respon se

of LEDs 1 - 3 00h Page 52

84h R/W LED Pulse 1 Period Controls the period of each breathe

during a pulse 20h Page 54

85h R/W LED Pulse 2 Period Controls the period of th e breathing

during breathe and pulse operation 14h Page 56

86h R/W LED Breathe Period Controls the period of an LED

breathe operation 5Dh Page 57

88h R/W LED Config Controls LED configuration 04h Page 57

90h R/W LED Pulse 1 Duty

Cycle Determines the min and max duty

cycle for the pulse operation F0h Page 58

91h R/W LED Pulse 2 Duty

Cycle Determines the min and max duty

cycle for breathe and pulse

operation F0h Page 58

92h R/W LED Breathe Duty

Cycle Determines the min and max duty

cycle for the breathe operation F0h Page 58

93h R/W LED Direct Duty Cycle Determines the min and max duty

cycle for Direct mode LED operation F0h Page 58

94h R/W LED Direct Ramp

Rates Determines the rising and falling

edge ramp rates of the LEDs 00h Page 59

95h R/W LED Off Delay Determines the off delay for all LED

behaviors 00h Page 60

B1h R Sensor Input 1

Calibration Stores the upper 8-bit calibration

value for sensor input 1 00h Page 64

B2h R Sensor Input 2

Calibration Stores the upper 8-bit calibration

value for sensor input 2 00h Page 64

B3h R Sensor Input 3

Calibration Stores the upper 8-bit calibration

value for sensor input 3 00h Page 64

B9h R Sensor Input

Calibration LSB 1 Stores the 2 LSBs of the calibration

value for sensor inputs 1 - 3 00h Page 64

FDh R Product ID Stores a fixed value that identifies

each product 54h Page 64

Table 5.1 Register Set in Hexadecim al Order (continued)

ADDRESS R/W REGISTER NAME FUNCTION DEFAULT

VALUE PAGE

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During Power-On-Reset (POR), the default val ues are stored in the registers. A POR is initiated when

power is first applied to the part and the voltage on the VDD supply surpasses the POR level as

specified in the electrical characteristics. Any reads to undefined registers will return 00h. Writes to

undefined registers will not have an effect.

When a bit is “set”, this means that the user writes a logic ‘1’ to it. When a b it is “cleared”, this means

that the user writes a logic ‘0’ to it.

5.1 Main Control Register

The Main Control register controls the primary power state of the device.

Bits 7 - 6 - GAIN[1:0] - Controls the gain used by the capa citive touch sensing circuitry. As the gain is

increased, the effective sensitivity is likewise increased as a smaller delta capacitance is required to

generate the same delta count values. The sensitivit y settings may need to be adjusted along with the

gain settings such that data overflow does not occur.

APPLICATION NOTE: The gain settings apply to both Standby and Active states.

Bit 5 - STBY - Enables Standby.

‘0’ (default) - Sensor input scanning is active and LEDs are functional.

‘1’ - Capacitive touch sensor input scanning is limited to the sensor inputs set in the Standby

Channel register (see Section 5.20). The status registers will not be cleared until read. LEDs that

are linked to capacitive touch sensor inputs will remain linked and active. Sensor inputs that are

FEh R Manufacturer ID Stores a fixed value that identifies

SMSC 5Dh Page 64

FFh R Revision Stores a fixed valu e that represents

the revision number 83h Page 64

Table 5.2 Main Control Register

ADDRR/W REGISTER B7 B6B5 B4 B3B2B1B0DEFAULT

00h R/W Main Control GAIN[1:0] STBY DSLEEP - - - INT 00h

Table 5.3 GAIN Bit Decode

GAIN[1:0]

CAPACITIVE TOUCH SENSOR GAIN10

00 1

01 2

10 4

11 8

Table 5.1 Register Set in Hexadecim al Order (continued)

ADDRESS R/W REGISTER NAME FUNCTION DEFAULT

VALUE PAGE

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no longer sampled will flag a release and then remain in a non-touched state. LEDs that are

manually controlled will be unaffected.

Bit 4 - DSLEEP - Enables Deep Sleep by deactivating all functions.

‘0’ (default) - Sensor input scanning is active and LEDs are functional.

‘1’ - All sensor input scanning is disabled. All LEDs are driven to their programmed non-actuated

state and no PWM operations will be done. The status registers are automa tically cleared and the

INT bit is cleared.

Bit 0 - INT - Indicates that there is an interrupt. When this bit is set, it asserts the ALERT# pin. If a

channel detects a touch and its associated interrupt enable bit is not set to a logic ‘1’, no action is

taken.

This bit is cleared by writing a logic ‘0’ to it. When this bit is cleare d, the ALERT# pin will be deasserted

and all status registers will be cleared if the condition has been removed.

‘0’ - No interrupt pending.

‘1’ - A touch has been detected on one or more channels and the interrupt has been asserted.

5.2 Status Registers

All status bits are cleared when the device enters the Deep Sleep (DSLEEP = ‘1’ - see Section 5.1).

5.2.1 General Status - 02h

Bit 4 - LED - Indicates that one or more LEDs have finished their programmed activity. This bit is set

if any bit in the LED Status register is set.

Bit 2 - MULT - Indicates that the device is blocking detected touches due to the Multiple Touch

detection circuitry (see Section 5.14). This bit will not cause the INT bit to be set and hence will not

cause an interrupt.

Bit 1 - MTP - Indicates that the device has detected a number of sensor inputs that exceed the MTP

threshold either via the pattern recognition or via the number of sensor inpu ts (see Section 5.15). This

bit will cause the INT bit to be set if the MTP_ALERT bit is also set. This bit will not be cleared until

the condition that caused it to be set has been removed.

Bit 0 - TOUCH - Indicates that a touch was detected. Th is bit is set if any bit in the Sensor Input Status

5.2.2 Sensor Input Status - 03h

The Sensor Input Status Register stores status bits that indicate a touch has been detected. A value

of ‘0’ in any bit indicates that no touch has been detected. A value of ‘1’ in any bit indicates that a

touch has been detected.

Table 5.4 Status Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

02h R General Status - - - LED - MULT MTP TOUCH 00h

03h R Sensor Input

Status - - - - - CS3 CS2 CS1 00h

04h R LED Status - - - - - LED3_

DN LED2_

DN LED1_

DN 00h

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All bits are cleared when the INT bit is cl eared and if a tou ch on the respe ctive capaciti ve touch sensor

input is no longer present. If a touch is still detected, th e bits will not be cleared (but this will not ca use

the interrupt to be asserted - see Section 5.6).

Bit 2 - CS3 - Indicates that a touch was detected on Sensor Input 3. This sensor input can be linked

to LED3.

Bit 1 - CS2 - Indicates that a touch was detected on Sensor Input 2. This sensor input can be linked

to LED2.

Bit 0 - CS1 - Indicates that a touch was detected on Sensor Input 1. This sensor input can be linked

to LED1.

5.2.3 LED Status - 04h

The LED Status Registers indicate when an LED has completed its configured behavior (see Section

5.31, "LED Behavior Register") after being actuated by the host (see Section 5.28, "LED Output

Control Register"). These bits are ignored when the LED is linked to a capacitive sensor in put. All LED

Status bits are cleared when the INT bit is cleared.

Bit 2 - LED3_DN - Indicates that LED3 has finished its behavior after being actuated by the host.

Bit 1 - LED2_DN - Indicates that LED2 has finished its behavior after being actuated by the host.

Bit 0 - LED1_DN - Indicates that LED1 has finished its behavior after being actuated by the host.

5.3 Noise Flag Status Registers

The Noise Flag Status registers store status bits that are generated from the analog block if the

detected noise is above the operating region of the analog detector or the RF noise detector. These

bits indicate that the most recently received data from the sensor input is invalid and should not be

used for touch detection. So long as the bit is set for a particular channel, the delta count value is reset

to 00h and thus no touch is detected.

These bits are not sticky and will be cleared automatically if the analog block does not report a noise

error.

APPLICATION NOTE: If the MTP detection circuitry is enabled, these bits count as sensor inputs above the MTP

threshold (see Section 4.3.4, "Multiple Touch Pattern Detection") even if the corresponding

delta count is not. If the corresponding delta count also exceeds the MT P threshold, it is not

counted twice.

APPLICATION NOTE: Regardless of the state of the Noise Status bits, if low frequency noise is detected on a

sensor input, that sample will be discarded unless the DIS_ANA_NOISE bit is set. As well,

if RF noise is detected on a sensor input, that sample will be discarded unless the

DIS_RF_NOISE bit is set.

Table 5.5 Noise Flag Status Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

0Ah R Noise Flag

Status ---CS3_

NOISE CS2_

NOISE CS1_

NOISE 00h

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5.4 Sensor Input Delta Count Registers

The Sensor Input Delta Count registers store the delta count that is compared against the threshold

used to determine if a touch has been detected. The count value represents a change in input due to

the capacitance associated with a touch on one of the sensor inputs and is referenced to a calibrated

base “Not Touched” cou nt value. The del ta is an instantaneous change and is updated once p er se nsor

input per sensing cycle (see Section 4.3.1, "Sensing Cycle").

The value presented is a standard 2’s complement number. In addition, the value is capped at a value

of 7Fh. A reading of 7Fh indicates that the sensitivity settings are too high and should be adjusted

accordingly (see Section 5.5).

The value is also capped at a negative value of 80h for negative delta counts which may result upon

a release.

5.5 Sensitivity Control Register

The Sensitivity Control register controls the sensitivity of a touch detection.

Bits 6-4 DELTA_SENSE[2:0] - Controls the sensitivity of a touch detection. The sensitivity settings act

to scale the relative delta count value higher or lower based on the system parameters. A setting of

000b is the most sensitive while a setting of 111b is the le ast sensitive. At the more sensitive settings,

touches are dete cted for a smaller delta capacitance corresponding to a “l ighter” touch. These settings

are more sensitive to no ise, however, and a noisy environment may flag more false touches with higher

sensitivity levels.

APPLICATION NOTE: A value of 128x is the most sensitive setting available. At the most sensitivity settings, the

MSB of the Delta Count register re presents 64 out of ~25,000 which co rresponds to a touch

of approximately 0.25% of the base capacitance (or a ΔC of 25fF from a 10pF base

capacitance). Conversely, a value of 1x is the least sensitive setting available. At these

settings, the MSB of the Delta Count register corresponds to a delta count of 8192 counts

out of ~25,000 which corresponds to a touch of approximately 33% of the base capacitance

(or a ΔC of 3.33pF from a 10pF base capacitance).

Table 5.6 Sensor Input Delta Count Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

10h R Sensor Input 1

Delta Count Sign 64 32 16 8 4 2 1 00h

11h R Sensor Input 2

Delta Count Sign 64 32 16 8 4 2 1 00h

12h R Sensor Input 3

Delta Count Sign 64 32 16 8 4 2 1 00h

Table 5.7 Sensitivity Control Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

1Fh R/W Sensitivity Control - DELTA_SENSE[2:0] BASE_SHIFT[3:0] 2Fh

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Bits 3 - 0 - BASE_SHIFT[3:0] - Controls the scaling and data presentation of the Base Count registers.

The higher the value of these bits, the larger the range and the lower the resolution of the data

presented. The scale factor represents the multiplier to the bit-weighting presented in these register

descriptions.

APPLICATION NOTE: The BASE_SHIFT[3:0] bits normally do not need to be updated. These settings will not affect

touch detection o r sensitivity. These bits are sometimes h elpful in analyzing the Cap Sensing

board performance and stability.

Table 5.8 DELTA_SENSE Bit Decode

DELTA_SENSE[2:0]

SENSITIVITY MULTIPLIER210

0 0 0 128x (most sensitive)

001 64x

0 1 0 32x (default)

011 16x

100 8x

101 4x

110 2x

1 1 1 1x - (least sensitive)

Table 5.9 BASE_SHIFT Bit Decode

BASE_SHIFT[3:0] DATA SCALING

FACTOR32 1 0

00 0 0 1x

00 0 1 2x

00 1 0 4x

00 1 1 8x

01 0 0 16x

01 0 1 32x

01 1 0 64x

0 1 1 1 128x

1 0 0 0 256x

All others 256x

(default = 1111b)

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5.6 Configuration Registers

The Configuration registers control general global functionality that affects the entire device.

5.6.1 Configuration - 20h

Bit 7 - TIMEOUT - Enables the timeout and idle functionality of the SMBus protocol.

‘0’ (default for Fu nctional Revision C) - T he SMBus ti meout and idle functiona lity are disabled. The

SMBus interface will not time out if the clock line is held low. Likewise, it will not reset if both the

data and clock lines are held high for longer than 200us. This is used for I2C compliance.

‘1’ (default for Functional Revision B) - The SMBus timeout and idle functional ity are enabled. The

SMBus interface will time out if the clock line is held low for longer than 30ms. Likewise, it will reset

if both the data and clock lines are held high for longer than 200us.

Bit 5 - DIS_DIG_NOISE - Determines whether the digital noise threshold (see Section 5.19, "Sensor

Input Noise Threshold Register") is used by the device. Setting this bit disables the feature.

‘0’ - The digital noise thresh old is use d. If a delta cou nt value excee ds the noise thre shold but do es

not exceed the touch threshold, the sample is discarded and not used for the automatic re-

calibration routine.

‘1’ (default) - The noise threshol d is disabled. Any delta count that is less than the touch threshold

is used for the automatic re-calibration routine.

Bit 4 - DIS_ANA_NOISE - Determines whether the analog noise filter is enabled. Setting this bit

disables the feature.

‘0’ (default) - If low frequency noise is detected by the analog block, the delta count on the

corresponding channel is set to 0. Note that this does not require that Noise Status bits be set.

‘1’ - A touch is not blocked even if low frequency noise is detected.

Bit 3 - MAX_DUR_EN - Determines whether the maximum duration recalibration is enabled.

‘0’ (default) - The maximum duration recalibration functionality is disabled. A touch may be held

indefinitely and no re-calibration will be performed on any sensor input.

‘1’ - The maximum duration recalibration functional ity is enabled. If a touch is held for longer than

the MAX_DUR bit settings, then the re-calibration routine will be restarted (see Section 5.8).

5.6.2 Configuration 2 - 44h

Bit 7 - INV_LINK_TRAN - Determines the behavior of the Linked LED Transition controls (see

Section 5.29).

‘0’ (default) - The Linked LED Transition controls set the min duty cycle equal to the max duty cycle.

‘1’ - The Linked LED Transition controls will invert the touch signal. For example, a touch signal

will be inverted to a non-touched signal.

Table 5.10 Configuration Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

20h R/W Configuration TIMEOUT - DIS_ DIG_

NOISE DIS_ ANA_

NOISE MAX_

DUR_EN --- A0h

(rev B)

20h

(rev C)

44h R/W Configuration 2 INV_LINK_

TRAN ALT_

POL BLK_PWR_

CTRL BLK_POL_

MIR SHOW_

RF_

NOISE

DIS_

RF_

NOISE -INT_

REL_n 40h

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Bit 6 - ALT_POL - Determines the ALERT# pin polarity and behavior.

‘0’ - The ALERT# pin is active high and push-pull.

‘1’ (default) - The ALERT# pin is active low and open drain.

Bit 5 - BLK_PWR_CTRL - Dete rmines whether the de vice will redu ce power consumption while waiting

between conversion time completion and the end of the polling cycle.

‘0’ (default) - The device will always power d own as much as possibl e during the time between the

end of the last conversion and the end of the polling cycle.

‘1’ - The device will not power down the Cap Sensor during the time between the end of the last

conversion and the end of the polling cycle.

Bit 4 - BLK_POL_MIR - Determin es whether the LED Mirror Control register bits are linked to the LED

Polarity bits. Setting this bit blocks the normal behavior which is to automatically set and clear the LED

Mirror Control bits when the LED Polarity bits are set or cleared.

‘0’ (default) - When the LED Polarity controls are set, the corresponding LED Mirror control is

automatically set. Likewise, when the LED Polarity controls are cleared, the corresponding LED

Mirror control is also cleared.

‘1’ - When the LED Polarity controls are set, the corresponding LED Mirror control is not

automatically set.

Bit 3 - SHOW_RF_NOISE - Determines whether the Noise Status bits will show RF Noise as the only

input source.

‘0’ (default) - The Noise Status registers will show both RF noise and low frequency EMI noise if

either is detected on a capacitive touch sensor input.

‘1’ - The Noise S tatus registers will only show RF noise if it is detected on a capacitive touch sensor

input. EMI noise will stil l be d etected a nd tou ches will be blocke d n ormally; howeve r, the status bits

will not be updated.

Bit 2 - DIS_RF_NOISE - Determines whether the RF noise filter is enabled. Setting this bit disables

the feature.

‘0’ (default) - If RF noise is detected by the analog block, the delta count on the corresponding

channel is set to 0. Note that this does not require that Noise Status bits be set.

‘1’ - A touch is not blocked even if RF noise is detected.

Bit 0 - INT_REL_n - Controls the interrupt behavior when a release is detected on a button.

‘0’ (default) - An interrupt is generated when a press is detected and again when a release is

detected and at the repeat rate (if enabled - see Section 5.13).

‘1’ - An interrupt is generated when a press is detected and at the repeat rate but not when a

release is detected.

5.7 Sensor Input Enable Registers

The Sensor Input Enable registers determine whether a capacitive touch sensor input is included in

the sampling cycle. The length of the sampling cycle is not affected by the number of sensor inputs

measured.

Table 5.11 Sensor Input Enable Registers

ADDRR/WREGISTERB7 B6B5B4B3B2B1B0DEFAULT

21h R/W Sensor Input

Enable - - - - - CS3_EN CS2_EN CS1_EN 07h

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Bit 2 - CS3_EN - Enables the CS3 input to be included during the sampling cycle.

‘0’ - The CS3 input is not included in the sampling cycle.

‘1’ (default) - The CS3 input is included in the sampling cycle.

Bit 1 - CS2_EN - Enables the CS2 input to be included during the sampling cycle.

Bit 0 - CS1_EN - Enables the CS1 input to be included during the sampling cycle.

5.8 Sensor Input Configuration Register

The Sensor Input Config uration Register controls timi ngs associated with the Capacitive sensor inputs

1 - 3.

Bits 7 - 4 - MAX_DUR[3:0] - (default 1010b) - Determines the maximum time that a sensor pad is

allowed to be touched until the capacitive touch sensor input is recalibrated, as shown in Table 5.13.

Table 5.12 Sensor Input Configuration Register

ADDRR/W REGISTER B7B6B5B4B3B2B1B0DEFAULT

22h R/W Sensor Input

Configuration MAX_DUR[3:0] RPT_RATE[3:0] A4h

Table 5.13 MAX_DUR Bit Decode

MAX_DUR[3:0]

TIME BEFORE RECALIBRATION32 1 0

0 0 0 0 560ms

0 0 0 1 840ms

0 0 1 0 1120ms

0 0 1 1 1400ms

0 1 0 0 1680ms

0 1 0 1 2240ms

0 1 1 0 2800ms

1 1 1 3360ms

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Bits 3 - 0 - RPT_RATE[3:0] - (default 0 100 b) Dete rmines the time d uration be twe en interrupt a sserti ons

when auto repeat is enabled. The resolution is 35ms the range is from 35ms to 560ms as shown in

Table 5.14.

1 0 0 0 3920ms

1 0 0 1 4480ms

1 0 1 0 5600ms (default)

1 0 1 1 6720ms

1 1 0 0 7840ms

1 1 0 1 8906ms

1 1 1 0 10080ms

1 1 1 1 11200ms

Table 5.14 RPT_RATE Bit Decode

RPT_RATE[3:0]

INTERRUPT REPEAT RATE3210

0000 35ms

0001 70ms

0 0 1 0 105ms

0 0 1 1 140ms

0 1 0 0 175ms (default)

0 1 0 1 210ms

0 1 1 0 245ms

0 1 1 1 280ms

1 0 0 0 315ms

1 0 0 1 350ms

1 0 1 0 385ms

1 0 1 1 420ms

1 1 0 0 455ms

1 1 0 1 490ms

1 1 1 0 525ms

1 1 1 1 560ms

Table 5.13 MAX_DUR Bit Decode (continued)

MAX_DUR[3:0]

TIME BEFORE RECALIBRATION32 1 0

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5.9 Sensor Input Configuration 2 Register

Bits 3 - 0 - M_PRESS[3:0] - (default 0111b) - Determines the minimum amount of time that sensor

inputs configured to use auto repeat must detect a sensor pad touch to detect a “press and hold” eve nt.

If the sensor input detects a touch for longer than the M_PRESS[3:0] settings, a “press and hold” event

is detected. If a sensor input detects a touch for less than or equal to the M_PRESS[3:0] settings, a

touch event is detected.

The resolution is 35ms the range is from 35ms to 560ms as shown in Table 5.16.

Table 5.15 Sensor Input Configuration 2 Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

23h R/W Sensor Input

Configuration 2 - - - - M_PRESS[3:0] 07h

Table 5.16 M_PRESS Bit Decode

M_PRESS[3:0]

M_PRESS SETTINGS3210

0000 35ms

0001 70ms

0 0 1 0 105ms

0 0 1 1 140ms

0 1 0 0 175ms

0 1 0 1 210ms

0 1 1 0 245ms

0 1 1 1 280ms (default)

1 0 0 0 315ms

1 0 0 1 350ms

1 0 1 0 385ms

1 0 1 1 420ms

1 1 0 0 455ms

1 1 0 1 490ms

1 1 1 0 525ms

1 1 1 1 560ms

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5.10 Averaging and Sampling Configuration Register

The Averaging and Sampling Config uration register controls the number of samples taken and th e total

sensor input cycle time for all active sensor inputs while the device is functioning in Active state.

Bits 6 - 4 - AVG[2:0] - Determines the number of sample s that are taken for all active channe ls during

the sensor cycle as shown in Table 5.18. All samples are taken consecutively on the same channel

before the next cha nnel is sampled and the resul t is averaged over the number of samples measured

before updating the measured results.

For example, if CS1, CS2, and CS3 are sampled during the sensor cycle, and the AVG[2:0] bits are

set to take 4 samples per channel, the n the full sensor cycle will be: C S1, CS1, CS1, CS1, CS2, CS2,

CS2, CS2, CS3, CS3, CS3, CS3.

Bits 3 - 2 - SAMP_TIME[1:0] - Determines the time to take a single sample as shown in Table 5.19.

Table 5.17 Averaging and Sampling Configuration Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

24h R/W Averaging and

Sampling

Config AVG[2:0] SAMP_TIME[1:0] CYCLE_TIME

[1:0] 39h

Table 5.18 AVG Bit Decode

AVG[2:0] NUMBER OF SAMPLES TAKEN

PER MEASUREMENT210

000 1

001 2

010 4

0 1 1 8 (default)

100 16

101 32

110 64

1 1 1 128

Table 5.19 SAMP_TIME Bit Decod e

SAMP_TIME[1:0]

SAMPLE TIME10

0 0 320us

0 1 640us

1 0 1.28ms (default)

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Bits 1 - 0 - CYCLE_TIME[1:0] - Determines the overall cycle time for all measured channels during

normal operation as shown in Table 5.20. All measured channels are sampled at the beginning of the

cycle time. If additional time is remaining, then the device is placed into a lower power state for the

remaining duration of the cycle.

APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is

less than the programmed cycle. The AVG[2:0] bits will take priority so that if more samples

are required than would normally be allowed during the cycle time, the cycle time will be

extended as necessary to accommodate the number of samples to be measured.

5.11 Calibration Activate Register

The Calibration Activate register forces the respective sensor inputs to be re-calibrated affecting both

the analog and digital blocks. During the re-calibration routine, the sensor inputs will not detect a press

for up to 600ms and the Sensor Input Base Count register values will be invalid. Duri ng this time, any

press on the corresponding sensor pads will invalidate the re-calib ration. When finished, the CALX[9 :0]

bits will be updated (see Section 5.39).

When the corresponding bit is set, the device will perform the calibration and the bit will be

automatically cleared once the re-calibration routine has finished.

Bit 2 - CS3_CAL - When set, the CS3 input is re-calibrated. This bit is automatically cleared once the

sensor input has been re-calibrated successfully.

Bit 1 - CS2_CAL - When set, the CS2 input is re-calibrated. This bit is automatically cleared once the

sensor input has been re-calibrated successfully.

1 1 2.56ms

Table 5.20 CYCLE_TIME Bit Decode

CYCLE_TIME[1:0]

OVERALL CYCLE TIME10

00 35ms

0 1 70ms (default)

1 0 105ms

1 1 140ms

Table 5.21 Calibration Activate Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

26h R/W Calibration

Activate ---

CS3_

CAL CS2_

CAL CS1_

CAL 00h

Table 5.19 SAMP_TIME Bit Decode (continued)

SAMP_TIME[1:0]

SAMPLE TIME10

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Bit 0 - CS1_CAL - When set, the CS1 input is re-calibrated. This bit is automatically cleared once the

sensor input has been re-calibrated successfully.

5.12 Interrupt Enable Register

The Interrupt Enable register determines whether a sensor pad touch or release (if enabled) causes

the interrupt pin to be asserted.

Bit 2 - CS3_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS3

(associated with the CS3 status bit).

‘0’ - The interrupt pin will not be asserted if a to uch is detected on CS3 (associated with the CS6

status bit).

‘1’ (default) - The interrupt pin will be asserted if a touch is detected on CS3 (associated with the

CS6 status bit).

Bit 1 - CS2_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS2

(associated with the CS2 status bit).

Bit 0 - CS1_INT_EN - Enables the interrupt pin to be asserted if a touch is detected on CS1

(associated with the CS1 status bit).

5.13 Repeat Rate Enable Register

The Repeat Rate Enable register enables the repeat rate of the sensor inputs as described in

Section 4.4.1.

Bit 2 - CS3_RPT_EN - Enables the repeat rate for capacitive touch sensor input 3.

‘0’ - The repeat rate for CS3 is d isabled. It will only generate an interrupt when a touch is detected

and when a release is detected no matter how long the touch is held for.

‘1’ (default) - The repeat rate for CS3 is ena bled. In the case of a “touch” event, it will ge nerate an

interrupt when a touch is detected and a release is detected (as determined by the INT_REL_n bit

- see Section 5.6). In the case of a “press and hold” event, it will generate an interrupt when a

touch is detected and at the repeat rate so long as the touch is held d.

Bit 1 - CS2_RPT_EN - Enables the repeat rate for capacitive touch sensor input 2.

Bit 0 - CS1_RPT_EN - Enables the repeat rate for capacitive touch sensor input 1.

Table 5.22 Interrupt Enable Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

27h R/W Interrupt

Enable ---

CS3_

INT_EN CS2_

INT_EN CS1_

INT_EN 07h

Table 5.23 Repeat Rate Enable Register

ADDRR/WREGISTERB7B6B5B4B3B2B1B0DEFAULT

28h R/W Repeat Rate

Enable -----

CS3_

RPT_EN CS2_

RPT_EN CS1_

RPT_EN 07h

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5.14 Multiple Touch Configuration Register

The Multiple To uch Configuration register controls th e settings for the multiple t ouch detection circuitry.

These settings determine the number of simultaneous buttons that may be pressed before additional

buttons are blocked and the MULT status bit is set.

Bit 7 - MULT_BLK_EN - Enables the multiple button blocking circuitry.

‘0’ - The multiple touch circuitry is disabled. The device will not block multiple touches.

‘1’ (default) - The multiple touch circuitry is enabled. The device will flag the number of touches

equal to programme d multiple touch threshold and block all others. It will remembe r which sensor

inputs are valid and block all others until that sensor pad has been released. Once a sensor pad

has been released, the N detected touches (determined via the cycle order of CS1 - CS3) will be

flagged and all others blocked.

Bits 3 - 2 - B_MULT_T[1:0] - Determines the number of simultaneous touches on all sensor pads

before a Multiple Touch Event is detected and sensor inputs are blocked. The bit decode is given by

Table 5.25.

5.15 Multiple Touch Pattern Configuration Register

The Multiple Touch Pattern Configuration register controls the settings for the multiple touch pattern

detection circuitry. This circuitry works like the multiple touch detection circuitry with the following

differences:

Table 5.24 Multiple Touch Configuration

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

2Ah R/W Multiple Touch

Config MULT_

BLK_

EN - - - B_MULT_T[1:0] - - 80h

Table 5.25 B_MULT_T Bit Decode

B_MULT_T[1:0]

NUMBER OF SIMULTANEOUS TOUCHES10

0 0 1 (default)

01 2

10 3

11 3

Table 5.26 Multiple Touch Pattern Configuration

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

2Bh R/W Multiple T ouch

Pattern Config MTP_ EN - - MTP_TH[1:0] COMP_

PTRN MTP_

ALERT 00h

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1. The detection threshold is a percentage of the touch detection threshold as defined by the

MTP_TH[1:0] bits whereas the multiple touch circuitry uses the touch detection threshold.

2. The MTP detection circuitry either will detect a specific pattern of sensor inputs as determined by

the Multiple To uch Pattern register settings or it will use the Multiple Touch Pattern register settings

to determine a minimum number of sensor inputs that will cause the MTP circuitry to flag an event.

When using pattern recognition mode, if all of the sensor inputs set by the Multiple Touch Pattern

Status bits set, the MTP bit will be set. When using the absolute number mode, if the number of

sensor inputs with thresholds above the MTP threshold or with Noise Flag Status bits set is equal

to or greater than this number, the MTP bit will be set.

3. When an MTP event occurs, all touches are blocked and an interrupt is generated.

4. All sensor inputs will remain blocked so long as the requisite number of sensor inputs are above

the MTP threshold or have Noise Flag Status bits set. Once this condition is removed, touch

detection will be restored. Note that the MTP status bit is only cleared by writing a ‘0’ to the INT

bit once the condition has been removed.

Bit 7 - MTP_EN - Enables the multiple touch pattern detection circuitry.

‘0’ (default) - The MTP detection circuitry is disabled.

‘1’ - The MTP detection circuitry is enabled.

Bits 3-2 - MTP_TH[1:0] - Determine the MTP threshold, as shown in Table 5.27. This threshold is a

percentage of sensor input threshold (see Section 5.18, "Sensor Input Threshold Re gisters") when the

device is in the Fully Active state or of the standby threshold (see Section 5.23, "Standby Threshold

Bit 1 - COMP_PTRN - Determines whether the MTP detection circuitry will use the Multiple Touch

Pattern register as a specific pattern of sensor inputs or as an absolute number of sensor inputs.

‘0’ (default) - The MTP detection circuitry will use the Multiple Touch Pattern register bit settings as

an absolute minimum number of sensor inputs that must be above the threshold or have Noise

Flag Status bits set. The number will be equal to the number of bits set in the register.

‘1’ - The MTP detection circuitry will use pattern recognition. Each bit set in the Multiple Touch

Pattern register indicates a specific sensor input tha t must have a delta count greater than the MTP

threshold or have a Noise Flag Status bit set. If the criteria are met, the MTP status bit will be set.

Bit 0 - MTP_ALERT - Enables an interrupt if an MTP event occurs. In either condition, the MTP status

bit will be set.

‘0’ (default) - If an MTP event occurs, the ALERT# pin is not asserted.

‘1’ - If an MTP event occurs, the ALERT# pin will be asserted.

Table 5.27 MTP_TH Bit Decode

MTP_TH[1:0]

THRESHOLD DIVIDE SETTING10

0 0 12.5% (default)

0125%

1 0 37.5%

1 1 100%

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DATASHEET

5.16 Multiple Touch Pattern Register

The Multiple Touch Pattern register acts as a pattern to identify an expected sensor input profile for

diagnostics or other significant events. There are two methods for how the Multiple Touch Pattern

threshold or have Noise Flag Status bits set. Which method is used is based on the COMP_PTRN bit

(see Section 5.15). The methods are described below.

1. Specific Sensor Inputs: If, during a single polling cycle, the specific sensor inputs above the MTP

threshold or with Noise Flag Status bits set match those bits set in the Multiple Touch Pattern

2. Number of Sensor Inputs: If, during a single polling cycle, the number of sensor inputs with a delta

count above the MTP threshold or with Noise Flag Status bits set is equal to or greater than the

number of pattern bits set, an MTP event is flagged.

Bit 2 - CS3_PTRN - Determines whether CS3 is considered as part of the Multiple Touch Pattern.

‘0’ - CS3 is not considered a part of the pattern.

‘1’ - CS3 is considered a part of the pattern or the absolute number of senso r inputs that must have

a delta count greater than the MT P threshold or have the No ise Flag Status bit set is increase d by

Bit 1 - CS2_PTRN - Determines whether CS2 is considered as part of the Multiple Touch Pattern.

Bit 0 - CS1_PTRN - Determines whether CS1 is considered as part of the Multiple Touch Pattern.

5.17 Recalibration Configuration Register

The Recalibration Configuration register controls the automatic re-calibration routine settings as well

as advanced controls to program the Sensor Input Threshold register settings.

Bit 7 - BUT_LD_TH - Enables setting all Sensor Input Threshold registers by writing to the Sensor

Input 1 Threshold register.

‘0’ - Each Sensor Input X Threshold register is updated individually.

‘1’ (default) - Writing the Sensor Input 1 Threshol d register will automatically overwrite the Se nsor

Input Threshold registers for all sensor inputs (Sensor Input Threshold 1 through Sensor Input

Threshold 3). The individual Sensor Input X Threshold registers (Sensor Input 2 Threshold and

Sensor Input 3 Threshold) can be individually updated at any time.

Table 5.28 Multiple Touch Pattern Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

2Dh R/W Multiple

Touch

Pattern ---

CS3_

PTRN CS2_

PTRN CS1_

PTRN 07h

Table 5.29 Recalibration Configuration Regis te r s

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

2Fh R/W Recalibration

Configuration BUT_

LD_TH NO_

CLR_

INTD

NO_

CLR_

NEG NEG_DELTA_

CNT[1:0] CAL_CFG[2:0] 8Ah

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Bit 6 - NO_CLR_INTD - Controls whether the accumulati on of intermediate data is cleared if the noise

status bit is set.

‘0’ (default) - The accumulation of intermediate data is cleared if the noise status bit is set.

‘1’ - The accumulation of intermediate data is not cleared if the noise status bit is set.

APPLICATION NOTE: Bits 5 and 6 should both be set to the same value. Either both should be set to ‘0’ or both

should be set to ‘1’.

Bit 5 - NO_CLR_NEG - Controls whether the consecutive negative delta counts counter is cleared if

the noise status bit is set.

‘0’ (default) - The consecutive negative delta counts counter is cleared if the noise status bit is set.

‘1’ - The consecutive negative delta counts counter is not cleared if the noise status bit is set.

Bits 4 - 3 - NEG_DELTA_CNT[1:0] - Determines the number of negative delta counts necessary to

trigger a digital re-calibration as shown in Table 5.30.

Bits 2 - 0 - CAL_CFG[2:0] - Determines the update time and number of samples of the automatic re-

calibration routine. The settings apply to all sensor inputs universally (though individual sensor inputs

can be configured to support re-calibration - see Section 5.11).

Table 5.30 NEG_DELTA_CNT Bit Decode

NEG_DELTA_CNT[1:0] NUMBER OF CONSECUTIVE NEGATIVE DELTA

COUNT VALUES10

00 8

0 1 16 (default)

10 32

1 1 None (disabled)

Table 5.31 CAL_CFG Bit Decode

CAL_CFG[2:0] RECALIBRATION

SAMPLES (SEE

Note 5.1) UPDATE TIME (SEE

Note 5.2)210

0 0 0 16 16

001 32 32

0 1 0 64 64 (default)

0 1 1 128 128

100 256 256

1 0 1 256 1024

1 1 0 256 2048

1 1 1 256 4096

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DATASHEET

Note 5.1 Recalibration Samples refers to the number of samples that are measured and averaged

before the Base Count is u pdate d ho wever does not con trol the base count upda te period.

Note 5.2 Update Time refers to the amount of time (i n polling cycle periods) that elapses before the

Base Count is updated. The time will depend upon the number of channels active, the

averaging setting, and the programmed cycle time.

5.18 Sensor Input Threshold Registers

The Sensor Input Threshold registers store the delta threshold that is used to determine if a touch has

been detected. When a touch occurs, the input signal of the corresponding sensor pad changes due

to the capacitance associated with a touch. If the sensor input change excee ds the threshold settings,

a touch is detected.

When the BUT_LD_TH bit is set (see Section 5.17 - bit 7), w riting data to the Sensor Inpu t 1 Thresho ld

5.19 Sensor Input Noise Threshold Register

The Sensor Input Noise Threshold register controls the value of a secondary internal threshold to

detect noise and improve the auto matic recalibration routine . If a capacitive touch sensor inpu t exceeds

the Sensor Input Noise Threshold but does not exceed the sensor input threshold, it is determined to

be caused by a noise spike. That sample is not used by the automatic re-calibration routine. This

feature can be disabled by setting the DIS_DIG_NOISE bit.

Bits 1-0 - CS1_BN_TH[1:0] - Controls the noise threshold for all capacitive touch sensor inputs, as

shown in Table 5.34. The threshold is proportional to the threshold setting.

Table 5.32 Sensor Input Threshold Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

30h R/W Sensor Inp ut 1

Threshold -6432168421 40h

31h R/W Sensor Inp ut 2

Threshold -6432168421 40h

32h R/W Sensor Inp ut 3

Threshold -6432168421 40h

Table 5.33 Sensor Input Noise Threshold Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

38h R/W Sensor Input

Noise Threshold CS_BN_TH

[1:0] 01h

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5.20 Standby Channel Register

The Standby Channel register controls which (if any) capacitive touch sensor inputs are active during

Standby.

Bit 2 - CS3_STBY - Controls whether the CS3 channel is active in Standby.

‘0’ (default) - The CS3 channel not be sampled during Standby mode.

‘1’ - The CS3 channel will be sampled during Standby Mode. It will use the Standby threshold

setting, and the standby averaging and sensitivity settings.

Bit 1 - CS2_STBY - Controls whether the CS2 channel is active in Standby.

Bit 0 - CS1_STBY - Controls whether the CS1 channel is active in Standby.

5.21 Standby Configuration Register

The Standby Configuration register controls averaging and cycle time for those sensor inputs that are

active in Standby. This register is useful for det ecting proximity on a small number of sensor inputs as

it allows the user to change averaging and sample times on a limited number of sensor inputs and still

maintain normal functionality in the fully active state.

Bit 7 - AVG_SUM - Determines whether the active sensor i nputs will average the p rogrammed number

of samples or whether they will accumulate for the programmed number of samples.

Table 5.34 CSx_BN_TH Bit Decode

CS_BN_TH[1:0]

PERCENT THRESHOLD SETTING10

0025%

0 1 37.5% (default)

1050%

1 1 62.5%

Table 5.35 Standby Channel Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

40h R/W Standby

Channel -----

CS3_

STBY CS2_

STBY CS1_

STBY 00h

Table 5.36 Standby Configuration Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

41h R/W Standby

Configuration AVG_

SUM STBY_AVG[2:0] STBY_SAMP_

TIME[1:0] STBY_CY_TIME

[1:0] 39h

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DATASHEET

‘0’ - (default) - The active sensor input delta count values will be based on the average of the

programmed number of samples when compared against the threshold.

‘1’ - The active sensor input delta count values will be based on the summation of the programmed

number of samples when compared against the threshold. This bit should only be set when

performing proximity detection as a physical touch will overflow the delta count registers and may

result in false readings.

Bits 6 - 4 - STBY_AVG[2:0] - Determines the number of samples that are taken for all active channels

during the sensor cycle as shown in Table 5.37. All samples are taken consecutively on the same

channel before the next channel is sampled and the result is averaged over the number of samples

measured before updating the measured results.

Bit 3-2 - STBY SAMP_TIME[1:0] - Determines the time to take a single sample when the device is in

Standby as shown in Table 5.38.

Bits 1 - 0 - STBY_CY_TIME[2:0] - Determines the overall cycle time for all measured channels during

standby operation as shown in Table 5.39. All measured channel s are sampled at the beginning of the

cycle time. If additional time is remaining, the device is placed into a lower power state for the

remaining duration of the cycle.

Table 5.37 STBY_AVG Bit Decode

STBY_AVG[2:0] NUMBER OF SAMPLES TAKEN

PER MEASUREMENT210

000 1

001 2

010 4

0 1 1 8 (default)

100 16

101 32

110 64

1 1 1 128

Table 5.38 STBY_SAMP_TIME Bit Decode

STBY_SAMP_TIME[1:0]

SAMPLING TIME10

0 0 320us

0 1 640us

1 0 1.28ms (default)

1 1 2.56ms

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APPLICATION NOTE: The programmed cycle time is only maintained if the total averaging time for all samples is

less than the programmed cycle. The STBY_AVG[2:0] bits will take priority so that if more

samples are required than would normally be allowed during the cycle time, the cycle time

will be extended as necessary to accommodate the number of samples to be measured.

5.22 Standby Sensitivity Register

The Standby Sensitivity register controls the sensitivity for sensor inputs that are active in Standby.

Bits 2 - 0 - STBY_SENSE[2:0] - Controls the sensitivity for sensor inputs that are active in Standby.

The sensitivity settings act to scale the relative delta count value higher or lower based on the system

parameters. A setting of 000b is the most sensitive while a setting of 111b is the least sensitive. At the

more sensitive settings, touches are detected for a smaller delta C corresponding to a “lighter” touch.

These settings are more sensitive to noise however and a noisy environment may flag more false

touches than higher sensitivity levels.

APPLICATION NOTE: A value of 128x is the most sensitive setting available. At the most sensitivity settings, the

MSB of the Delta Count register re presents 64 out of ~25,000 which co rresponds to a touch

of approximately 0.25% of the base capacitance (or a ΔC of 25fF from a 10pF base

capacitance). Conversely a value of 1x is the least sensitive setting available. At these

settings, the MSB of the Delta Count register corresponds to a delta count of 8192 counts

out of ~25,000 which corresponds to a touch of approximately 33% of the base capacitance

(or a ΔC of 3.33pF from a 10pF base capacitance).

Table 5.39 STBY_CY_TIME Bit Decode

STBY_CY_TIME[1:0]

OVERALL CYCLE TIME10

00 35ms

0 1 70ms (default)

1 0 105ms

1 1 140ms

Table 5.40 Sta nd by Sensitivity Register

ADDRR/WREGISTER B7 B6B5B4B3B2B1B0DEFAULT

42h R/W Standby

Sensitivity - - - - - STBY_SENSE[2:0] 02h

Table 5.41 STBY_SENSE Bit Decode

STBY_SENSE[2:0]

SENSITIVITY MULTIPLIER210

0 0 0 128x (most sensitive)

001 64x

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DATASHEET

5.23 Standby Threshold Register

The Standby Threshold register stores the delta threshol d that is used to dete rmine if a touch h as been

detected. When a touch occurs, the input signal of the corresponding sensor pad changes due to the

capacitance associated with a touch. If the sensor input change exceeds the threshold settings, a

touch is detected.

5.24 Sensor Input Base Count Registers

The Sensor Input Base Count registers store the calibrated “Not Touched” input value from the

capacitive touch sensor inputs. These registers are periodically updated by the re-calibration routine.

The routine uses an internal adder to add the current count value for each reading to the sum of the

previous readings until sample size has been reached. At this point, the upper 16 bits are taken and

used as the Sensor Input Base Count. The internal adder is then reset and the re-calibration routine

continues.

The data presented is determined by the BASE_SHIFT[3:0] bits (see Section 5.5).

0 1 0 32x (default)

011 16x

100 8x

101 4x

110 2x

1 1 1 1x - (least sensitive)

Table 5.42 Standby Threshold Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

43h R/W Standby

Threshold -6432168421 40h

Table 5.43 Sensor Input Base Count Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

50h R Sensor Input 1

Base Count 128 64 32 16 8 4 2 1 C8h

51h R Sensor Input 2

Base Count 128 64 32 16 8 4 2 1 C8h

52h R Sensor Input 3

Base Count 128 64 32 16 8 4 2 1 C8h

Table 5.41 STBY_SENSE Bit Decode (continued)

STBY_SENSE[2:0]

SENSITIVITY MULTIPLIER210

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5.25 LED Output Type Register

The LED Output Type register controls the type of output for the LED pins. Each pin is controlled by

a single bit. Refer to application note 21.4 CAP1188 Family LED Configuration Options for more

information about implementing LEDs.

Bit 2 - LED3_OT - Determines the output type of the LED3 pin.

‘0’ (default) - The LED3 pin is an open-drain output with an external pull-up resistor. When the

appropriate pin is set to the “active” state (logic ‘1’), the pin will be driven low. Conversely, when

the pin is set to the “inactive” state (logic ‘0’), the pin will be left in a High Z state and pulled high

via an external pull-up resistor.

‘1’ - The LED3 pin is a push-pull output. When driving a logic ‘1’, the pin is driven high. When

driving a logic ‘0’, the pin is driven low.

Bit 1 - LED2_OT - Determines the output type of the LED2 pin.

Bit 0 - LED1_OT - Determines the output type of the LED1 pin.

5.26 Sensor Input LED Linking Register

The Sensor Input LED L inking register controls whet her a capacitive touch sensor input is lin ked to an

LED output. If the correspondi ng bit is set, then the appropriate LED output will cha nge states defined

by the LED Behavior controls (see Section 5.31) in response to the capacitive touch sensor input.

Bit 2 - CS3_LED3 - Links the LED3 o utput to a detected touch on the CS3 sensor in put. When a touch

is detected, the LED is actuated and will behave as determined by the LED Behavior controls.

‘0’ (default) - The LED 3 output is not associated with the CS3 input. If a touch is detected on the

CS3 input, the LED will not automatically be actuated. The LED is enabled and controlled via the

LED Output Control regi ster (see Section 5.28) and the LED Behavior registers (see Section 5.31).

‘1’ - The LED 3 output is associated with the CS3 input. If a touch is detected on the CS3 input,

the LED will be actuated and behave as defined in Table 5.52.

Bit 1 - CS2_LED2 - Links the LED2 o utput to a detected touch on the CS2 sensor in put. When a touch

is detected, the LED is actuated and will behave as determined by the LED Behavior controls.

Bit 0 - CS1_LED1 - Links the LED1 o utput to a detected touch on the CS1 sensor in put. When a touch

is detected, the LED is actuated and will behave as determined by the LED Behavior controls.

Table 5.44 LED Output Type Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

71h R/W LED Output

Type -----

LED3_

OT LED2_

OT LED1_

OT 00h

Table 5.45 Sensor Input LED Linking Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

72h R/W Sensor

Input LED

Linking -----

CS3_

LED3 CS2_

LED2 CS1_

LED1 00h

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DATASHEET

5.27 LED Polarity Register

The LED Polarity register controls the logical polarity of the LED outputs. When these bits are set or

cleared, the corresponding LED Mirror controls are also set or cleared (unless the BLK_POL_MIR bit

is set - see Section 5.6, "Configuration Registers"). Table 5.48, "LED Polarity Behavior" shows the

interaction between the polarity controls, output controls, and relative brightness.

APPLICATION NOTE: The polarity controls determine the final LED pin drive. A touch on a linked capacitive touch

sensor input is treated in the same way as the LED Output Control bit being set to a logic ‘1’.

APPLICATION NOTE: The LED drive assumes that the LEDs are configured such that if the LED pin is driven to

a logic ‘0’ then the LED will be on an d that the CAP1133 LED pin is sinking the LED current.

Conversely, if the LED pin is driven to a logic ‘1’, the LED will be off and there is no current

flow. See Figure 4.1, "System Diagram for CAP1133".

APPLICATION NOTE: This application note applies when the LED polarity is inverted (LEDx_POL = ‘0’). For LED

operation, the duty cycle settings determine the % of time that the LED pin will be driven to

a logic ‘0’ state in. The Max Duty Cycle settings define the ma ximum % of time that the LED

pin will be driven low (i.e. maximum % of time that the LED is on) while the Min Duty Cycle

settings determine the minimum % of time that the LED pin will be driven low (i .e. minimum

% of time that the LED is on). When there is no touch detected or the LED Output Control

Breathe operations will ramp the duty cycle from the minimum duty cycle to the maximum

duty cycle.

APPLICATION NOTE: This application note applies when the LED polarity is non-inverted (LEDx_POL = ‘1’). For

LED operation, the duty cycle settings determine the % of time that the LED pin will be driven

to a logic ‘1’ state. The Max Duty Cycle setting s define the maximum % of time that the LED

pin will be driven hi gh (i.e. maximum % of time that the LED is off) while the Min Duty Cycle

settings determine the minimum % of time that the LED pin will be driven high (i.e. mi nimum

% of time that the LED is off). When there is no touch detected or the LED Output Control

cycle setting. Breathe operations will ramp the du ty cycle from 100 minus the minimum duty

cycle to 100 minus the maximum duty cycle.

APPLICATION NOTE: The LED Mirror controls (see Section 5.30, "LED Mirror Control Register") work with the

polarity controls with respect to LED brightness but wil l not have a direct effect on the output

pin drive.

Bit 2 - LED3_POL - Determines the polarity of the LED3 output.

‘0’ (default) - The LED3 o utput is inverted. For example, a setting of ‘1’ in the LED Output Control

‘1’ - The LED3 output is non-inverted. For example, a setting of ‘1’ in the LED Output Control

determined by its output type

Bit 1 - LED2_POL - Determines the polarity of the LED2 output.

Bit 0 - LED1_POL - Determines the polarity of the LED1 output.

Table 5.46 LED Polarity Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

73h R/W LED Polarity - - - - - LED3_

POL LED2_

POL LED1_

POL 00h

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5.28 LED Output Control Register

The LED Output Control Register cont rols the output state of the LED pi ns that are not linke d to se nsor

inputs.

Note: If an LED is linked to a sensor input in the Sensor Input LED Linking Register (Section 5.26,

"Sensor Input LED Linking Reg ister"), the co rresponding bit in the LED Ou tput Control Register

is ignored (i.e. a linked LED cannot be host controlled).

The LED Polarity Control Regi ster will determine the non actuated state of the LED pins. The actuated

LED behavior is determin ed by t he LED be havior con trols (see Section 5.31, "LED Beha vior Regi ster" ).

Table 5.48 shows the interaction between the polarity cont rols, ou tp ut controls, and relative brig htness.

Bit 2 - LED3_DR - Determines whether LED3 output is driven high or low.

‘0’ (default) - The LED3 output is driven at the minimum duty cycle or not actuated.

‘1’ - The LED3 output is driven at the maximum duty cycle or is actuated.

Bit 1 - LED2_DR - Determines whether LED2 output is driven high or low.

Bit 0 - LED1_DR - Determines whether LED1 output is driven high or low.

Table 5.47 LED Output Control Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

74h R/W LED Output

Control -----

LED3_

DR LED2_

DR LED1_

DR 00h

Table 5.48 LED Polarity Behavior

LED

OUTPUT

CONTROL

OR TOUCH POLARITY MAX DUTY MIN DUTY BRIGHTNESS LED

APPEARANCE

0inverted

(‘0’) not used minimum % of

time that the L ED

is on (logic 0) maximum brightness

at min duty cycle on at min duty

cycle

1inverted

(‘0’) maximum % of

time that the LED

is on (logic 0)

minimum % of

time that the L ED

is on (logic 0)

maximum brightness

at max duty cycle.

Brightness ramps

from min duty cycle

to max duty cycle

according to

LED behavior

0non-

inverted

(‘1’) not used minimum % of

time that the L ED

is off (logic 1)

maximum brightness

at 100 minus min

duty cycle. on at 100 - min

duty cycle

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5.29 Linked LED Transition Control Register

The Linked LED Transition Control register controls the LED drive when the LED is linked to a

capacitive touch sensor input. These controls work in conjunction with the INV_LINK_TRAN bit (see

Section 5.6.2, "Configuration 2 - 44h") to create smooth transitions from host control to linked LEDs.

Bit 2 - LED3_LTRAN - Determines the transition effect when LED3 is linked to CS3.

‘0’ (default) - When the LED output control bit for CS3 is ‘1’, and then CS3 is linked to LED3 and

no touch is detected, the LED will change states.

‘1’ - If the INV_LINK_TRAN bit i s ‘1’, when the LED output contro l bit for CS3 is ‘1’, and then CS3

is linked to LED3 and no touch is detected, the LED will not change states. In addition, the LED

state will change when th e sensor pad is touched. If the INV_LINK_TRAN bit is ‘0’, when the LED

output control bit fo r CS3 is ‘1’, and then CS3 is linked to LED3 and no touch is detected, th e LED

will not change states. However, the LED state will not change when the sensor pad is touched.

APPLICATION NOTE: If the L ED behavio r is not “D irect” and the INV_LINK_TRAN b it it ‘0’, the LED wil l n ot perform

as expected when the LED3_LTRAN bit is set to ‘1’. Therefore, if breathe and pulse

behaviors are used, set the INV_LINK_TRAN bit to ‘1’.

Bit 1 - LED2_LTRAN - Determines the transition effect when LED2 is linked to CS2.

Bit 0 - LED1_LTRAN - Determines the transition effect when LED1 is linked to CS1.

1non-

inverted

(‘1’)

maximum % of

time that the LED

is off (logic 1)

minimum % of

time that the L ED

is off (logic 1)

For Direct behavior,

maximum brightness

is 100 minus max

duty cycle. When

breathing, max

brightness is 100

minus min du ty cycle.

Brightness ramps

from 100 - min duty

cycle to 100 - max

duty cycle.

according to

LED behavior

Table 5.49 Linked LED Transition Control Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

77h R/W Linked LED

Transition

Control -----

LED3_

LTRAN LED2_

LTRAN LED1_

LTRAN 00h

Table 5.48 LED Polarity Behavior (continued)

LED

OUTPUT

CONTROL

OR TOUCH POLARITY MAX DUTY MIN DUTY BRIGHTNESS LED

APPEARANCE

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5.30 LED Mirror Control Register

The LED Mirror Control Registers determine the meaning of duty cycle settings when polarity is non-

inverted for each LED channel. When the polarity bit is set to ‘1’ (non-inverted), to obtain correct steps

for LED ramping, pulse, and breathe behaviors, the min and max duty cycles need to be relative to

100%, rather than the default, which is relative to 0%.

APPLICATION NOTE: The LED drive assumes that the LEDs are configured such that if the LED pin is driven to

a logic ‘0’, the LED will be on and the CAP1133 LED pin is sinking the LED current. When

the polarity bit is set to ‘1’, it is considered non-inverted. For systems using the opposite LED

configuration, mirror controls would apply when the polarity bit is ‘0’.

These bits are changed automatically if the corresponding LED Polarity bit is changed (unless the

BLK_POL_MIR bit is set - see Section 5.6).

Bit 2 - LED3_MIR_EN - Determines whether the duty cycle settings are “biased” relative to 0% or 100%

duty cycle.

‘0’ (default) - The duty cycle settings are determined relative to 0% and are determined directly with

the settings.

‘1’ - The duty cycle settings are determined relative to 100%.

Bit 1 - LED2_MIR_EN - Determines whether the duty cycle settings are “biased” relative to 0% or 100%

duty cycle.

Bit 0 - LED1_MIR_EN - Determines whether the duty cycle settings are “biased” relative to 0% or 100%

duty cycle.

5.31 LED Behavior Register

The LED Behavior register controls the operation of LEDs. Each LED pin is controlled by a 2-bit field

and the behavior is determined by whether the LED is linked to a capacitive touch sensor input or not.

If the corresponding LED output is linked to a capacitive touch sensor input, the appropriate behavior

will be enabled / disabled based on touches and releases.

If the LED output is not associated with a capacitive touch sensor input, the appropriate behavior will

be enabled / disabled by the LED Output Control register. If the respective LEDx_DR bit is set to a

logic ‘1’, this will be associated as a “touch”, and if the LEDx_DR bit is set to a logic ‘0’, this will be

associated as a “release”.

Table 5.50 LED Mirror Control Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

79h R/W LED Mirror

Control -----

LED3_

MIR_

LED2_

MIR _

LED1_

MIR _

EN 00h

Table 5.51 LED Behavior Registe r

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

81h R/W LED Behavior 1 - - LED3_CTL[1:0] LED2_CTL[1:0] LED1_CTL[1:0] 00h

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 53 Revision 1.32 (01-05-12)

DATASHEET

Table 5.52, "LEDx_CTL Bit Decode" shows the behavior triggers. The defined behavior will activate

when the Start Trigger is met and will stop when the Stop Trigger is met. Note the behavior of the

Breathe Hold and Pulse Release option.

The LED Polarity Control reg ister will determine the non actuated state of the LED outputs (see Section

5.27, "LED Polarity Register").

APPLICATION NOTE: If an LED is not linked to a capacitive touch sensor input and is breathing (via the Breathe

or Pulse behaviors), it must be unactuated and then re-a ctuated before chang es to behavior

are processed. For example, if the LED output is breathing and the Maximum duty cycle is

changed, this change will not take effect until the LED ou tput control register is set to ‘0’ a nd

then re-set to ‘1’.

APPLICATION NOTE: If an LED is not linked to the capacitive touch sensor input and configured to operate using

Pulse 1 Behavior, then the circuitry will only be actuated when the corresponding output

control bit is set. It will not check the bit condition until the Pulse 1 behavior is finished. The

device will not remember if the bit was cleared and reset while it was actuated.

APPLICATION NOTE: If an LED is actuated and not linked and the desired LED behavior is changed, this new

behavior will take effect immediately; however, the first instance of the changed behavior

may act incorrectly (e.g. if changed from Direct to Pulse 1, the LED output may ‘breathe’ 4

times and then end at minimum duty cycle). LED Behaviors will operate normally once the

LED has been un-actuated and then re-actuated.

APPLICATION NOTE: If an LED is actuated and it is switched from linked to a capacitive touch sensor input to

unlinked (or vice versa), the LED will respond to the new command source immediately if

the behavior was Direct or Breathe. For Pulse behaviors, it will complete the behavior

already in progress. For example, if a linked LED was actuated by a touch and the control

is changed so that it is unlinked, it will check the status of the corresponding LED Output

Control bit. If that bit is ‘0’, then the LED will behave as if a release was detected. Li kewise,

if an unlinked LED was actuated by the LED Output Control register and the control is

changed so that it is linked and no touch is detected, then the LED wi ll behave as if a rele ase

was detected.

Bits 5 - 4 - LED3_CTL[1:0] - Determines the behavior of LED3 as shown in Table 5.52.

Bits 3 - 2 - LED2_CTL[1:0] - Determines the behavior of LED2 as shown in Table 5.52.

Bits 1 - 0 - LED1_CTL[1:0] - Determines the behavior of LED1 as shown in Table 5.52.

Table 5.52 LEDx_CTL Bit Decode

LEDX_CTL

[1:0]

OPERATION DESCRIPTION START

TRIGGER STOP

TRIGGER10

0 0 Direct The LED is driven to the programmed state

(active or inactive). See Figure 5.7 Touch Detected

or LED Output

Control bit set

Release

Detected or

LED Output

Control bit

cleared

01 Pulse 1

The LED will “Pulse” a programmed

number of times. During each “Pulse” the

LED will breathe up to the maximum

brightness and back down to the minimum

brightness so that the total “Pulse” period

matches the programmed value.

Touch or

Release

Detected or LED

Output Control

bit set or cleared

(see

Section 5.32)

n/a

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Revision 1.32 (01-05-12) 54 SMSC CAP1133

DATASHEET

APPLICATION NOTE: The PWM frequency is determined based on the selected LED behavior, the programmed

breathe period, and the programmed min and max duty cycles. For the Direct behavior

mode, the PWM frequency is calculated based on the programmed Rise and Fall times. If

these are set at 0, then the maximum PWM frequency will be used based on the

programmed duty cycle settings.

5.32 LED Pulse 1 Period Register

The LED Pulse Period 1 register determines the overall period of a pulse operation as determined by

the LED_CTL registers (see Table 5.52 - setting 01b). The LSB represents 32ms so that a setting of

18h (24d) would represent a period of 768ms (24 x 32ms = 768ms). The total range is from 32ms to

4.064 seconds as shown in Table 5.54 with the default being 1024ms.

APPLICATION NOTE: Due to constraints on the LED Drive PWM operation, any Breathe Period less than 160ms

(05h) may not be achievable. The device will breathe at the minimum period possible as

determined by the period and min / max duty cycle settings.

Bit 7 - ST_TRIG - Determines the start trigger for the LED Pulse behavior.

‘0’ (default) - The LED will Pulse when a touch is detected or the drive bit is set.

‘1’ - The LED will Pulse when a release is detected or the drive bit is cleared.

The Pulse 1 operation is shown in Figure 5.1 when the LED output is configured for non-inverted

polarity (LEDx_POL = 1) and in Figure 5.2 for inverted polarity (LEDx_POL = 0).

1 0 Pulse 2

The LED will “Pulse” when the start trigger

is detected. When the stop trigger is

detected, it will “Pulse” a programmable

number of times then return to its minimum

brightness.

Touch Detected

or LED Output

Control bit set

Release

Detected or

LED Output

Control bit

cleared

1 1 Breathe

The LED will breathe. It wil l be driven with

a duty cycle that ramps up from the

programmed minimum duty cycle (default

0%) to the programmed maximum duty

cycle duty cycle (default 100%) and then

back down. Each ramp takes up 50% of the

programmed period. The total period of

each “breath” is determined by the LED

Breathe Period controls - see Section 5.34.

Touch Detected

or LED Output

Control bit set

Release

Detected or

LED Output

Control bit

cleared

Table 5.53 LED Pulse 1 Period Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

84h R/W LED Pulse

1 Period ST_

TRIG P1_

PER6 P1_

PER5 P1_

PER4 P1_

PER3 P1_

PER2 P1_

PER1 P1_

PER0 20h

Table 5.52 LEDx_CTL Bit Decode (continued)

LEDX_CTL

[1:0]

OPERATION DESCRIPTION START

TRIGGER STOP

TRIGGER10

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DATASHEET

Figure 5.1 Pulse 1 Behavior with Non-Inverted Polarity

Figure 5.2 Pulse 1 Behavior with Inverted Polarity

Table 5.54 LED Pulse / Breathe Period Example

SETTING

(HEX) SETTING (DECIMAL) TOTAL BREATHE / PULSE

PERIOD (MS)

00h 0 32

01h 1 32

02h 2 64

Normal – untouched

operation Normal – untouched

operation

Touch Detected or

Release Detected

(100% - Pulse 1 Max Duty Cycle) * Brightness

X pulses after touch or after release

Pulse 1 Period

(P1_PER)

(100% - Pulse 1 Min Duty Cycle) * Brightness

LED

Brightness

Normal – untouched

operation

Normal – untouched

operation

Touch Detected or

Release Detected

Pulse 1 Min Duty Cycle * Brightness

X pulses after touch or after release

Pulse Period

(P1_PER)

Pulse 1 Max Duty Cycle * Brightness

LED

Brightness

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 56 SMSC CAP1133

DATASHEET

5.33 LED Pulse 2 Period Register

The LED Pulse 2 Period register determines the overall period of a pulse operation as determined by

the LED_CTL registers (see Table 5.52 - setting 10b). The LSB represents 32ms so that a setting of

18h (24d) would represent a period of 768ms. The total range is from 32ms to 4.064 seconds (see

Table 5.54) with a default of 640ms.

APPLICATION NOTE: Due to constraints on the LED Drive PWM operation, any Breathe Period less than 160ms

(05h) may not be achievable. The device will breathe at the minimum period possible as

determined by the period and min / max duty cycle settings.

The Pulse 2 Behavior is shown in Figure 5.3 for non-inverted polarity (LEDx_POL = 1) and in

Figure 5.4 for inverted polarity (LEDx_POL = 0).

03h 3 96

. . . . . . . . .

7Dh 125 4000

7Eh 126 4032

7Fh 127 4064

Table 5.55 LED Pulse 2 Period Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

85h R/W LED Pulse 2

Period -P2_

PER6 P2_

PER5 P2_

PER4 P2_

PER3 P2_

PER2 P2_

PER1 P2_

PER0 14h

Figure 5.3 Pulse 2 Behavior with Non-Inverted Polarity

Table 5.54 LED Pulse / Breathe Period Example (continued)

SETTING

(HEX) SETTING (DECIMAL) TOTAL BREATHE / PULSE

PERIOD (MS)

. . .

Normal – untouched

operation Normal – untouched

operation

Touch D etected

(100% - Pulse 2 Min Duty Cycle) *

Brightness

(100% - Pulse 2 Max Duty Cycle) * Brightness

X additional pulses after release

Release Detected

Pulse

Period

(P2_PER)

LED

Brightness

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 57 Revision 1.32 (01-05-12)

DATASHEET

5.34 LED Breathe Period Register

The LED Breathe Period register determines the overall period of a breathe operation as determined

by the LED_CTL registers (see Table 5.52 - setting 11b). The LSB represents 32ms so that a setting

of 18h (24d) would represent a period of 768ms. The total range is from 32ms to 4.064 seconds (see

Table 5.54) with a default of 2976ms.

APPLICATION NOTE: Due to constraints on the LED Drive PWM operation, any Breathe Period less than 160ms

(05h) may not be achievable. The device will breathe at the minimum period possible as

determined by the period and min / max duty cycle settings.

5.35 LED Configuration Register

The LED Configuration register controls general LED behavior as well as the number of pulses that

are sent for the PULSE LED output behavior.

Bit 6 - RAMP_ALERT - Determines whether the device will assert the ALERT# pin when LEDs

actuated by the LED Output Control register bits have finished their respective behaviors. Interrupts

will only be generated if the LED activity is generated by writing the LED Outpu t Control registers. Any

LED activity associated with touch detection will not cause an interrupt to be generated when the LED

behavior has been finished.

Figure 5.4 Pulse 2 Behavior with Inverted Polarity

Table 5.56 LED Breathe Perio d Reg ister

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

86h R/W LED Breathe

Period -BR_

PER6 BR_

PER5 BR_

PER4 BR_

PER3 BR_

PER2 BR_

PER1 BR_

PER0 5Dh

Table 5.57 LED Configuration Regis te r

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

88h R/W LED Config - RAMP_

ALERT PULSE2_CNT[2:0] PULSE1_CNT[2:0] 04h

Normal – untouched

operation Normal – untouched

operation

Touch D etected

Pulse 2 Max Duty Cycle * Brightness

Pulse 2 Min Duty Cycle * Brightness

X additional pulses after release

Release Detected

Pulse

Period

(P2_PER)

LED

Brightness . . .

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Revision 1.32 (01-05-12) 58 SMSC CAP1133

DATASHEET

‘0’ (default) - The ALERT# pin will not be asserted when LEDs actuated by the LED Output Control

‘1’ - The ALERT# pin will be asserted whenever any LED that is actuated by the LED Output

Control register has finished its programmed behavior.

Bits 5 - 3 - PULSE2_CNT[2:0] - Determines the number of pulses used for the Pulse 2 behavior as

shown in Table 5.58.

Bits 2 - 0 - PULSE1_CNT[2:0] - Determines the number of pulses used for the Pulse 1 behavior as

shown in Table 5.58.

5.36 LED Duty Cycle Registers

The LED Duty Cycle registers determine the minimum and maximum duty cycle settings used for the

LED for each LED behavior. These settings affect the brightness of the LED when it is fully off and

fully on.

The LED driver duty cycle will ramp up from the minimum duty cycle to the maximum duty cycle and

back down again.

Table 5.58 PULSEX_CNT Decode

PULSEX_CNT[2:0]

NUMBER OF BREATHS21 0

0 0 0 1 (default - Pulse 2)

00 1 2

01 0 3

01 1 4

1 0 0 5 (default - Pulse 1)

10 1 6

11 0 7

11 1 8

Table 5.59 LED Duty Cycle Registers

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

90h R/W LED Pulse 1

Duty Cycle P1_MAX_DUTY[3:0] P1_MIN_DUTY[3:0] F0h

91h R/W LED Pulse 2

Duty Cycle P2_MAX_DUTY[3:0] P2_MIN_DUTY[3:0] F0h

92h R/W LED Breathe

Duty Cycle BR_MAX_DUTY[3:0] BR_MIN_DUTY[3:0] F0h

93h R/W Direct Duty

Cycle DR_MAX_DUTY[3:0] DR_MIN_DUTY[3:0] F0h

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 59 Revision 1.32 (01-05-12)

DATASHEET

APPLICATION NOTE: When operating in Direct behavior mode, changes to the Duty C ycle settings will be applied

immediately. When operating in Breathe, Pulse 1, or Pulse 2 modes, the LED must be

unactuated and then re-actuated before changes to behavior are processed.

Bits 7 - 4 - X_MAX_DUTY[3:0] - Determines the maximum PWM duty cycle for the LED drivers as

shown in Table 5.60.

Bits 3 - 0 - X_MIN_DUTY[3:0] - Determines the minimum PWM duty cycle for the LED drivers as

shown in Table 5.60.

5.37 LED Direct Ramp Rates Register

The LED Direct Ramp Rates register control the rising and falling edge time of an LED that is

configured to operate in Direct behavior mo de. The risin g edge time co rresponds to the amount of time

the LED takes to transition from its minimum duty cycle to its maximum duty cycle. Conversely, the

Table 5.60 LED Duty Cycle Decode

X_MAX/MIN_DUTY [3:0] MAXIMUM DUTY

CYCLE MINIMUM DUTY

CYCLE3210

0 0 0 0 7% 0%

0 0 0 1 9% 7%

0010 11% 9%

0 0 1 1 14% 11%

0100 17% 14%

0101 20% 17%

0110 23% 20%

0111 26% 23%

1000 30% 26%

1001 35% 30%

1010 40% 35%

1011 46% 40%

1100 53% 46%

1101 63% 53%

1110 77% 63%

1 1 1 1 100% 77%

Table 5.61 LED Direct Ramp Rates Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

94h R/W LED Direct

Ramp Rates - - RISE_RATE[2:0] FALL_RATE[2:0] 00h

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Datasheet

Revision 1.32 (01-05-12) 60 SMSC CAP1133

DATASHEET

falling edge time corre sponds to the amount of time that the LED takes to transition from its maximum

duty cycle to its minimum duty cycle.

Bits 5 - 3 - RISE_RATE[2:0] - Determines the rising edge time of an LED when it transitions from its

minimum drive state to its maximum drive state as shown in Table 5.62.

Bits 2 - 0 - FALL_RATE[2:0] - Determines the falling edge time of an LED when it transitions from its

maximum drive state to its minimum drive state as shown in Table 5.62.

5.38 LED Off Delay Register

The LED Off Delay register determines the amount of time that an LED remains at its maximum duty

cycle (or minimum as determined by the polarity controls) before it starts to ramp down. If the LED is

operating in Breathe mode, this delay is applied at the top of each “breath”. If the LED is operating in

the Direct mode, this delay is applied when the LED is unactuated.

Bits 6 - 4 - BR_OFF_DLY[2:0] - Determines th e Breathe behavior mode off delay, which is the amount

of time an LED in Breathe behavior mode remains inactive after it finishes a breathe pulse (ramp on

and ramp off), as shown in Figure 5.5 (non-inverted polarity LEDx_POL = 1) and Figure 5.6 (inverted

polarity LEDx_POL = 0). Available settings are shown in Table 5.64.

Table 5.62 Rise / Fall Rate Decode

RISE_RATE/ FALL_RATE/ BIT DECODE

RISE / FALL TIME (TRISE / TFALL))21 0

00 0 0

0 0 1 250ms

0 1 0 500ms

0 1 1 750ms

10 0 1s

10 1 1.25s

11 0 1.5s

11 1 2s

Table 5.63 LED Off Delay Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

95h R/W LED Off Delay

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Datasheet

SMSC CAP1133 61 Revision 1.32 (01-05-12)

DATASHEET

Figure 5.5 Breathe Behavior with Non-Inverted Polarity

Figure 5.6 Breathe Behavior with Inverted Polarity

LED Actuated

100% - Breathe Max Min Cycle * Brightness

100% - Breathe Min Duty Cycle *

Brightness

LED Unactuated

Breathe Off

Delay

(BR_OFF_DLY)

LED

Brightness

Breathe

Period

(BR_PER)

LED Actuated

Breathe Max Duty Cycle * Brightness

Breathe Min Duty Cycle * Brightness

LED Unactuated

Breathe Off

Delay

(BR_OFF_DLY)

LED

Brightness

Breathe

Period

(BR_PER)

3 Channel Capacitive Touch Sensor with 3 LED Drivers

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Revision 1.32 (01-05-12) 62 SMSC CAP1133

DATASHEET

Bits 3 - 0 - DIR_OFF_DLY[3:0] - Determines the turn-off delay, as shown in Table 5.65, for all LEDs

that are configured to operate in Direct behavior mode.

The Direct behavior operation is determined by the combination of programmed Rise Time, Fall Time,

Min and Max Duty cycles, Off Delay, and polarity. Figure 5.7 shows the behavior for non-inverted

polarity (LEDx_POL = 1) while Figure 5.8 shows the behavior for inverted polarity (LEDx_POL = 0).

Table 5.64 Breathe Off Delay Settings

BR_OFF_DLY [2:0]

OFF DELAY210

0 0 0 0 (default)

0 0 1 0.25s

010 0.5s

0 1 1 0.75s

100 1.0s

1 0 1 1.25s

110 1.5s

111 2.0s

Figure 5.7 Direct Behavior for Non-Inverted Polarity

Normal –

untouched

operation

RISE_RATE

Setting (tRISE)(1 0 0 % - Ma x Du ty

Cycle) * Brightness

Touch

Detected Release

Detected

O ff De la y

(tOFF_DLY)FA LL_RATE

S e ttin g (tFALL)

Norm al –

untouched

operation

(100% - Min Duty Cycle) *

Brightness

LED

Brightness

3 Channel Capacitive Touch Sensor with 3 LED Drivers

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DATASHEET

Figure 5.8 Direct Behavior for Inverted Polarity

Table 5.65 Off Delay Decode

OFF DELAY[3:0] BIT DECODE

OFF DELAY (TOFF_DLY)32 1 0

00 0 0 0

0 0 0 1 250ms

0 0 1 0 500ms

0 0 1 1 750ms

01 0 0 1s

01 0 1 1.25s

0 1 1 0 1.5s

01 1 1 2s

1 0 0 0 2.5s

1 0 0 1 3.0s

1 0 1 0 3.5s

1 0 1 1 4.0s

1 1 0 0 4.5s

All others 5.0s

Normal –

untouched

operation RISE_RATE

S e tting (tRISE)

M in Duty Cycle * Brightness

Touch

Detected Release

Detected

Off D e la y

(tOFF_DLY)FALL_RATE

S e ttin g (tFALL)

Normal –

untouched

operation

M ax Duty Cycle * Brightness

LED

Brightness

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 64 SMSC CAP1133

DATASHEET

5.39 Sensor Input Calibration Registers

The Sensor Input Calibration registers hold the 10-bit value that represents the last calibration value.

5.40 Product ID Register

The Product ID register stores a unique 8-bit value that identifies the device.

5.41 Manufacturer ID Register

The Vendor ID register stores an 8-bit value that represents SMSC.

5.42 Revision Register

The Revision register stores an 8-bit value that represents the part revision.

Table 5.66 Sensor Input Calibration Registers

ADDR REGISTER R/W B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

B1h Sensor Input 1

Calibration R CAL1_9 CAL1_8 CAL1_7 CAL1_6 CAL1_5 CAL1_4 CAL1_3 CAL1_2 00h

B2h Sensor Input 2

Calibration R CAL2_9 CAL2_8 CAL2_7 CAL2_6 CAL2_5 CAL2_4 CAL2_3 CAL2_2 00h

B3h Sensor Input 3

Calibration R CAL3_9 CAL3_8 CAL3_7 CAL3_6 CAL3_5 CAL3_4 CAL3_3 CAL3_2 00h

B9h Sensor Input

Calibration

LSB 1 R - - CAL3_1 CAL3_0 CAL2_1 CAL2_0 CAL1_1 CAL1_0 00h

Table 5.67 Product ID Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

FDhR Product ID 01010100 54h

Table 5.68 Vendor ID Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

FEh RManufacturer ID01011101 5Dh

Table 5.69 Revision Register

ADDR R/W REGISTER B7 B6 B5 B4 B3 B2 B1 B0 DEFAULT

FFhR Revision 10000011 83h

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 65 Revision 1.32 (01-05-12)

DATASHEET

Chapter 6 Package Information

6.1 CAP1133 Package Drawings

Figure 6.1 10-Pin DFN 3mm x 3mm Package Drawings

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Datasheet

Revision 1.32 (01-05-12) 66 SMSC CAP1133

DATASHEET

Figure 6.2 10-Pin DFN 3mm x 3mm Package Dimensions

Figure 6.3 10-Pin DFN 3mm x 3mm PCB Footprint

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 67 Revision 1.32 (01-05-12)

DATASHEET

6.2 Package Marking

Figure 6.4 CAP1133 Package Marking

BOTTOM

LINE 1: Device code,

First 2 of last 6 digits of Lot Number

LINE 2: Last 4 digits of Lot Number

LINES 1 & 2: CENTER HORIZONTAL ALIGNMENT

PB-FREE/GREEN SYMBOL

(Ni/Pd PP-LF)

2x 0.6

TOP

PIN 1

LINE 3: AS SHOWN

BOTTOM MARKING IS NOT ALLOWED

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Datasheet

Revision 1.32 (01-05-12) 68 SMSC CAP1133

DATASHEET

Appendix A Device Delta

A.1 Delta from CAP1033 to CAP1133

1. Updated circuitry to improve power supply rejection.

2. Updated LED driver duty cycle decode values to have more distribution at lower values - closer to

a logarithmic curve. See Table 5.60, "LED Duty Cycle Decode".

3. Updated bug that breathe periods were not correct above 2.6s. This includes rise / fall time

decodes above 1.5s.

4. Added 1 bit to the LED Off Delay register (see Section 5.38, "LED Off Delay Register") to extend

times from 2s to 5s in 0.5s intervals.

5. Breathe behavior modified. A breathe off delay control was added to the LED Off Delay Register

(see Section 5.38, "LED Off Delay Register") so the LEDs can be configured to remain inactive

between breathes.

6. Added controls for the LED transition effects when linking LEDs to capacitive sensor inputs. See

Section 5.29, "Linked LED Transition Control Register".

7. Added controls to “mirror” the LED duty cycle outputs so that when polarity changes, the LED

brightness levels look right. These bits are automatically set when polarity is set. Added control to

break this auto-set behavior. See Section 5.30, "LED Mirror Control Register".

8. Added Multiple Touch Pattern detection circuitry. See Section 5.15, "Multiple Touch Pattern

Configuration Register".

9. Added General Status register to flag Multiple touches, Multiple Touch Pattern issues and general

touch detections. See Section 5.2, "Status Registers".

10. Added bits 6 and 5 to the Recalibration Configuration register (2Dh - see Section 5.17,

"Recalibration Configuration Register"). These bits control whether the accumulation of

intermediate data and the consecutive negative delta counts counter are cleared when the noise

status bit is set.

11. Added Configuration 2 register for LED linking controls, noise detection controls, and control to

interrupt on press but not on release. Added control to change alert pin polarity. See Section 5.6,

"Configuration Registers".

12. Updated Deep Sleep behavior so that device does not clear DSLEEP bit on received

communications but will wake to communicate.

13. Cha nged PWM frequency for LED drivers. The PW M frequency was derived from the programmed

breathe period and duty cycle settings and it ran ged from ~4Hz to ~8000 Hz. The PWM frequency

has been updated to be a fixed value of ~2000Hz.

14. Register delta:

Table A.1 Register Delta From CAP1033 to CAP1133

ADDRESS REGISTER DELTA DELTA DEFAULT

00h

Page 26 Changed - Main Status

/ Control added bits 7-6 to control gain 00h

02h

Page 27 New - General Status new register to store MTP, MULT, LED,

and general TOUCH bits 00h

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SMSC CAP1133 69 Revision 1.32 (01-05-12)

DATASHEET

44h

Page 31 New - Configuration 2 new register to control alert polarity, LED

touch linking behavior, LED output

behavior, and noise detection, and

interrupt on release 40h

24h

Page 36 Changed - Averaging

Control updated register bits - moved

SAMP_AVG[2:0] bits and added

SAMP_TIME bit 1. Default changed 39h

2Bh

Page 39 New - Multiple Touch

Pattern Configuration new register for Multiple Touch Pattern

configuration - enable and threshold

settings 80h

2Dh

Page 41 New - Multiple Touch

Pattern Register new register for Multiple Touch Pattern

detection circuitry - pattern or number of

sensor inputs 07h

2Fh

Page 41 Changed -

Recalibration

Configuration

updated register - updated CAL_CFG b it

decode to add a 128 averages setting

and removed highest time setting.

Default changed. Added bit 6

NO_CLR_INTD and bit 5 NO_CLR_NEG.

8Ah

38h

Page 43 Changed - Sensor

Input Noise Threshold

updated register bits - removed bits 7 - 3

and consolidated all controls into bits 1 -

0. These bits will set the noise threshold

for all channels. Default changed 01h

39h Removed - Noise

Threshold Register 2 removed register n/a

41h

Page 44 Changed - Standby

Configuration updated register bits - moved

STBY_AVG[2:0] bits and added

STBY_TIME bit 1. Default changed 39h

77h

Page 51 New - Linked LED

Transition Control new register to control transition effect

when LED linked to sensor inputs 00h

79h

Page 52 New - LED Mirror

Control new register to control LED output

mirroring for brightness control when

polarity changed 00h

90h

Page 58 Changed - LED Pulse 1

Duty Cycle changed bit decode to be more

logarithmic F0h

91h

Page 58 Changed - LED Pulse 2

Duty Cycle changed bit decode to be more

logarithmic F0h

92h

Page 58 Changed - LED

Breathe Duty Cycle changed bit decode to be more

logarithmic F0h

93h

Page 58 Changed - LED Direct

Duty Cycle changed bit decode to be more

logarithmic F0h

95h Added controls - LED

Off Delay Added bits 6-4 BR_OFF_DLY[2:0]

Added bit 3 DIR_OFF_DLY[3] 00h

FDh

Page 64 Changed - Product ID Changed bit decode for CAP1133 54h

Table A.1 Register Delta From CAP1033 to CAP1133 (continued)

ADDRESS REGISTER DELTA DELTA DEFAULT

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

Revision 1.32 (01-05-12) 70 SMSC CAP1133

DATASHEET

Chapter 7 Datasheet Revision History

Table 7.1 Customer Revision History

REVISION LEVEL & DATE SECTION/FIGURE/ENTRY CORRECTION

Rev. 1.32 (01-05-12) Table 2.2, "Electrical

Specifications" Added conditions for tHD:DAT.

Section 3.2.7, "SMBus and

I2C Compatibility" Renamed from “SMBus and I2C Compliance.”

First paragraph, added last sentence: “For

information on using the CAP1133 in an I2C

system, refer to SMSC AN 14.0 SMSC Dedicated

Slave Devices in I2C Systems.”

Added: CAP1133 supports I2C fast mode at

400kHz. This covers the SMBus max time of

100kHz.

Section 5.4, "Sensor Input

Delta Count Registers" Changed negative value cap from FFh to 80h.

Rev. 1.31 (08-18-11) Section 3.3.3, "SMBus Send

Byte" Added an application note: The Send Byte protocol

is not functional in Deep Sleep (i.e., DSLEEP bit is

set).

Section 3.3.4, "SMBus

Receive Byte" Added an application note: The Receive Byte

protocol is not functional in Deep Sleep (i.e.,

DSLEEP bit is set).

Section 5.2, "Status

Registers" Removed RESET as bit 3 in register 02h.

Rev. 1.3 (05-18-11) Section 5.42, "Revision

Section 5.2, "Status

Registers" Added RESET as bit 3 in register 02h.

Rev. 1.2 (02-10-11) Section A.8, "Delta from Rev

B (Mask B0) to Rev C (Mask

B1)"

Added.

Table 2.2, "Electrical

Specifications" PSR improvements made in functional revision B.

Changed PSR spec from ±100 typ and ±200 max

counts / V to ±3 and ±10 counts / V. Conditions

updated.

Section 4.3.2, "Recalibrating

Sensor Inputs" Added more detail wi th subheading s for each type

of recalibration.

Section 5.6, "Configuration

Registers" Added bit 5 BLK_ PWR_CTRL to th e Config uration

2 Register 44h.

The TIMEOUT bit is set to ‘1’ by default for

functional revision B and is set to ‘0’ by default for

functional revision C.

Section 5.42, "Revision

82h.

Rev. 1.1 (11-17-10) Document Updated for functional revision B. See Section A.7,

"Delta from Rev A (Mask A0) to Rev B (Mask B0)".

3 Channel Capacitive Touch Sensor with 3 LED Drivers

Datasheet

SMSC CAP1133 71 Revision 1.32 (01-05-12)

DATASHEET

Cover Added to General Description: “includes circuitry

and support for enhanced sensor proximity

detection.”

Added the following Features:

Calibrates for Parasitic Capacitance

Analog Filtering for System Noise Sources

Press and Hold feature for Volume-like

Applications

Table 2.2, "Electrical

Specifications" Conditions for Power Supply Rejection modified

adding the following:

Sampling time = 2.56ms

Averaging = 1

Negative Delta Counts = Disabled

All other parameters default

Section 5.11, "Calibration

Activate Register" Updated register description to indicate which re-

calibration routine is used.

Section 5.14, "Multiple

Touch Configuration

Updated register description to indicate what will

happen.

T able 5.34, "CSx_BN_TH Bit

Decode" Table heading changed from “Threshold Divide

Setting” to “Percent Threshold Setting”.

Rev. 1.0 (06-14-10) Initial release

Table 7.1 Cust omer Revision History (continued)

REVISION LEVEL & DATE SECTION/FIGURE/ENTRY CORRECTION

Mouser Electronics

Authorized Distributor

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CAP1133-1-AIA-TR