QT60645-AS - Quantum Research Group

LQQT60325, QT60485, QT60645

PRELIMINARY

32, 48, 64 K

QMatrix

™

EYPANEL

ENSOR

Advanced second generation QMatrix controllers

Up to 32, 48 or 64 touch keys through any dielectric

Panel thicknesses to 5 cm or more

100% autocal for life - no adjustments required

Keys individually adjustable for sensitivity, response time,

and many other critical parameters

Mix and match key sizes & shapes in one panel

Passive matrix - no components at the keys

Moisture suppression capable

AKS™ - Adjacent Key Suppression feature

Synchronous noise suppression

Sleep mode with wake pin

SPI Slave or Master/Slave interface to a host controller

Low overhead communications protocol

44-pin TQFP package

APPLICATIONS

Automotive panels

Machine tools

ATM machines

Touch-screens

Appliance controls

Outdoor keypads

Security keypanels

Industrial keyboards

The QT60325, QT60485, and QT60645 digital charge-transfer (“QT”) QMatrix™ ICs are designed to detect human touch on up to

32, 48, or 64 keys respectively using a scanned, passive X-Y matrix. It will project the keys through almost any dielectric, e.g.

glass, plastic, stone, ceramic, and even wood, up to thicknesses of 5 cm or more. The touch areas are defined as simple 2-part

interdigitated electrodes of conductive material, like copper or screened silver or carbon deposited on the rear of a control panel.

Key sizes, shapes and placement are almost entirely arbitrary; sizes and shapes of keys can be mixed within a single panel of

keys and can vary by a factor of 20:1 in surface area. The sensitivity of each key can be set individually via simple functions over

the SPI port, for example via Quantum’s QmBtn program. Key setups are stored in an onboard eeprom and do not need to be

reloaded with each power-up.

These ICs are designed specifically for appliances, electronic kiosks, security panels, portable instruments, machine tools, or

similar products that are subject to environmental influences or even vandalism. They permit the construction of 100% sealed,

watertight control panels that are immune to humidity, temperature, dirt accumulation, or the physical deterioration of the panel

surface from abrasion, chemicals, or abuse. To this end the devices contain Quantum-pioneered adaptive self-calibration, drift

compensation, and digital filtering algorithms that make the sensing function robust and survivable. The devices use short dwell

times and Quantum’s patent-pending AKS™ feature to permit operation in wet environments.

The parts use a passive key matrix, dramatically reducing cost over older technologies that require an ASIC for every key. The

key-matrix can be made of standard flex material (e.g. Silver on PET plastic) or ordinary PCB material to save cost.

External circuitry consists of an opamp, R2R ladder-DAC network, a common PLD, a FET switch, and a small number of resistors

and capacitors which can fit into a footprint of roughly 8 sq. cm (1.5 sq. in). Control and data transfer is via a SPI port which can

be configured in either a Slave or Master/Slave mode.

QT60xx5 ICs make use of an important new variant of charge-transfer sensing, transverse charge-transfer, in a matrix format that

minimizes the number of required scan lines to provide a high economy of scale.

Pat Pend. R1.05/0802

DRDY

LED

Vss

Vdd

AIN

CSR

CZ1

Vdd

Vss

YC0

YC1

YC2

YC3

MOSI

MISO

SCLK

RST

Vdd

Vss

XTO

XTI

X2WS YC4

YC5

YC6

YC7

AVdd

AGnd

Aref

YS2

YS1

YS0

CZ21

11 23

44 43 42 41 40 39 38 37 36 34

12 13 14 22

19 2018

1615

QT60325

QT60485

QT60645

TQFP-44

QT60645-AS-40

C to +105

QT60485-AS-40

C to +105

QT60325-AS-40

C to +105

QT60645-S0

C to +70

QT60485-S0

C to +70

QT60325-S0

C to +70

TQFPT

AVAILABLE OPTIONS

1 0x31 - Delta Signal for Single Key

.......................

0 0x30 - Signal for Single Key

..........................

5.3 Status Commands

.................................

y 0x79 - Column Keys Scope

...........................

x 0x78 - Row Keys Scope

.............................

S 0x53 - All Keys Scope

..............................

s 0x73 - Specific Key Scope

...........................

5.2 Scope Commands

.................................

p 0x70 - Put Command

..............................

g 0x67 - Get Command

..............................

5.1 Direction Commands

...............................

5 Commands & Functions

.............................

4.6 Eeprom Corruption

.................................

4.5 Sensor Echo and Data Response

.......................

4.4 SPI Master-Slave Mode

.............................

4.3 SPI Slave-Only Mode

...............................

4.2 Protocol Overview

.................................

4.1 Serial Port specifications

.............................

4 Serial Interface

.....................................

3.22 ESD / Noise Considerations

..........................

3.21 Power Supply and PCB Layout

........................

3.20 Oscilloscope Sync

................................

3.19 CSR Drive Polarity

................................

3.18 LED / Alert Output

................................

3.17 Sleep_Wake / Noise Sync

...........................

3.16 Startup / Calibration Times

..........................

3.15 Oscillator

.......................................

3.14 Reset Input

.....................................

3.13 Water Film Suppression

............................

3.12 R2R Resistor Ladder

..............................

3.11 Sample Capacitors

................................

3.10 Opamps

.......................................

3.9 PLD Circuit and Charge Sampler

.......................

3.8 Burst Spacing

....................................

3.7 Intra-Burst Spacing

.................................

3.6 Burst Length & Sensitivity

............................

3.5.2 Noise Coupling Into Y Lines

..........................

3.5.1 RFI From Y Lines

................................

3.5 'Y' Gate Drives

....................................

3.4.2 Noise Coupling Into X lines

..........................

3.4.1 RFI From X Lines

..................................

3.4 'X' Electrode Drives

..................................

3.3 Signal Path

........................................

3.2 Matrix Scan Sequence

................................

3.1 Part Differences

.....................................

3 Circuit Operation

.....................................

2.12 Device Status & Reporting

.............................

2.11 Boundary Error Reporting

.............................

2.10 Full Recalibration

...................................

2.9 Adjacent Key Suppression (AKS™)

.......................

2.8 Reference Guardbanding

..............................

2.7 Positive Recalibration Delay

............................

2.6 Detect Integrator (‘DI’)

.................................

2.5 Detection Recalibration Delay

...........................

2.4 Drift Compensation

...................................

2.3 Hysteresis

.........................................

2.2 Positive Threshold

...................................

2.1 Negative Threshold

..................................

2 Signal Processing

....................................

1.4 Communications

....................................

1.3 Matrix Configuration

..................................

1.2 Circuit Model

.......................................

1.1 Field Flows

........................................

1 Overview

............................................

9 Index

.............................................

8.2 Marking

.........................................

8.1 Dimensions

......................................

8 Mechanical

........................................

7.5 Maximum Drdy Response Delays

.......................

7.4 Timing

.........................................

7.3 DC Specifications

..................................

7.2 Recommended operating conditions

.....................

7.1 Absolute Maximum Specifications

......................

7 Electrical Specifications

............................

6 PLD Source Listing

.................................

5.7 Timing Limitations

.................................

5.6 Function Summary Table

............................

^W 0x17 - Noise Sync

...............................

^V 0x16 - Boundary Equation Constant C2

...................

^U 0x15 - Boundary Eqn Constant C1, LSB

..................

^T 0x14 - Boundary Eqn Constant C1, MSB

..................

^S 0x13 - Cs Clamp Polarity

............................

^R 0x12 - Oscilloscope Sync

...........................

^Q 0x11 - Data Rate Selection

..........................

Z 0x5A - Enter Sleep

................................

W 0x57 - Return Part Signature

.........................

V 0x56 - Return Part Version

...........................

r 0x72 - Reset Device

...............................

l 0x6C - Return Last Command Character

...................

b 0x62 - Recalibrate Keys

.............................

L 0x4C - Lock Reference Levels

.........................

D 0x44 - DAC Test

.................................

6 0x36 - Eeprom Checksum

...........................

5.5 Supervisory / System Functions

........................

^P 0x10 - Adjacent Key Suppression (‘AKS’)

..................

^O 0x0F - Negative Reference Error Band

...................

^N 0x0E - Positive Reference Error Band

....................

^M 0x0D - Intra-Burst Pulse Spacing

.......................

^L 0x0C - Negative Recalibration Delay

.....................

^K 0x0B - Positive Recalibration Delay

.....................

^J 0x0A - Detect Integrator Limit

.........................

^I 0x09 - Positive Drift Compensation Rate

...................

^H 0x08 - Negative Drift Compensation Rate

..................

^G 0x07 - Burst Spacing

..............................

^E 0x05 - Dwell Time in Machine Cycles

.....................

^D 0x04 - Positive Threshold Hysteresis

.....................

^C 0x03 - Negative Threshold Hysteresis

....................

^B 0x02 - Positive Detect Threshold

.......................

^A 0x01 - Negative Detect Threshold

.......................

5.4 Setup Commands

.................................

K 0x4B - Key Touch Reporting for Group

...................

k 0x6B - Reporting of First Touched Key

....................

e 0x65 - Error Code for Selected Key

.....................

% 0x25 - Detect Integrator Counts for Group

.................

$ 0x24 - Charge Cancellation for Group

....................

# 0x23 - R2R Offset for Group

..........................

" 0x22 - Reference Levels for Group

......................

! 0x21 - Delta Signals for Group

.........................

<sp> 0x20 - Signal Levels for Group

.......................

7 0x37 - General Device Status

.........................

6 0x36 - Eeprom Checksum

...........................

5 0x35 - Detection Integrator Counts

......................

4 0x34 - Cz State

..................................

3 0x33 - R2R Offset

................................

2 0x32 - Reference Value

.............................

www.qprox.com

QT60xx5 / R1.05

Contents

Table 1.1 Device Pin List

Slave select for SPI direction control; active lowIO ODSS44

Y gate control to drive Y dwell timing circuitOYG43

X7 Drive matrix scanOX742

Data ready output for Slave SPI mode; active lowO ODDRDY41

Active low LED status drive / Activity indicatorOLED40

GroundPwrVss39

+5 supplyPwrVdd38

SPI Mode / Sync out. Connect via 10k resistor to Vcc or Gnd for mode. Scope sync yields Pulse.I/O ODMS37

Analog input from amplifierIAin36

Charge integrator reset line. Active high or active low (select polarity via Setups)OCSR35

Charge cancellation drive for CZ1 capacitorOCZ134

Charge cancellation drive for CZ2 capacitorOCZ233

Transfer switch control bit 0OYS032

Transfer switch control bit 1OYS131

Transfer switch control bit 2OYS230

Analog reference, connect to VccPwrAref29

Analog groundPwrAGnd28

+5 supply for analog sectionsPwrAVdd27

Y 7 Line clamp controlOYC726

Y 6 Line clamp controlOYC625

Y 5 Line clamp controlOYC524

Y 4 Line clamp controlOYC423

Y 3 Line clamp controlOYC322

Y 2 Line clamp controlOYC221

Y 1 Line clamp controlOYC120

Y 0 Line clamp controlOYC019

GroundPwrVss18

+5 supplyPwrVdd17

X summation / R2R DAC Ladder driveOXS16

X6 Drive matrix scan / R2R DAC Ladder driveOX615

X5 Drive matrix scan / R2R DAC Ladder driveOX514

X4 Drive matrix scan / R2R DAC Ladder driveOX413

X3 Drive matrix scan / R2R DAC Ladder driveOX312

X2 Drive matrix scan / R2R DAC Ladder drive / Wake from Sleep / Sync to noise sourceOX2WS11

X1 Drive matrix scan / R2R DAC Ladder driveOX110

X0 Drive matrix scan / R2R DAC Ladder driveOX09

Oscillator drive input. Connect to resonator or crystal, or external clock source.IXTI8

Oscillator drive output. Connect to resonator or crystal. Can drive a charge pump circuit for Vee

supply

OXTO7

GroundPwrVss6

+5 supplyPwrVdd5

Reset input, active low resetIRST4

SPI Clock. In Master mode is an output; in Slave mode is an inputI/O PPSCK3

Master-In / Slave Out SPI line. Not used in Master/Slave SPI mode.

In Slave mode outputs data to host (out only).

I/O PPMISO2

Master-Out / Slave In SPI line. In Master/Slave SPI mode is used for both communication directions.

In Slave SPI mode is the data input (in only).

I/O PPMOSI1

DescriptionTypeNamePin

I/O: I = Input

O = Output

Pwr = Power pin

I/O = Bi-directional line

PP = Push Pull output drive

OD = Open drain output drive

©Quantum Research Group Ltd.

iii

www.qprox.com

QT60xx5 / R1.05

1 Overview

QMatrix devices are digital burst mode charge-transfer (QT)

sensors designed specifically for matrix geometry touch

controls; they include all signal processing functions

necessary to provide stable sensing under a wide variety of

changing conditions. Only a few external parts are required

for operation. The entire circuit can be built within 8 square

centimeters of PCB area.

QMatrix devices include charge cancellation methods which

allow for a wide range of key sizes and shapes to be mixed

together in a single touch panel. These features permit the

construction of entirely new classes of keypads never before

contemplated, such as touch-sliders, back-illuminated keys,

and complex warped panel shapes, all at very low cost.

The devices use an SPI interface running at up to 1.5MHz to

allow key data to be extracted and to permit individual key

parameter setup. The interface protocol uses simple single

byte commands and responds with single byte responses in

most cases. The command structure is designed to minimize

the amount of data traffic while maximizing the amount of

information conveyed.

In addition to normal operating

and setup functions the device

can also report back actual

signal strengths and error codes.

QmBtn software for the PC can

be used to program the IC as

well as read back key status and

signal levels in real time.

QMatrix parts employ transverse

charge-transfer ('QT') sensing, a

new technology that senses

changes in the charge forced

across an electrode by a digital

edge.

The parts are electrically

identical with the exception of the

number of keys which may be

sensed.

1.1 Field Flows

Figure 1-1 shows how charge is

transferred across an electrode

set to permeate the overlying

panel material; this charge flow

exhibits a high dQ/dt during the

edge transitions of the X drive pulse. The charge emitted by

the X electrode is partly received onto the corresponding Y

electrode which is then processed. The parts use 8 'X'

edge-driven rows and 8 'Y' sense columns to permit up to 64

keys. Keys are typically formed from interleaved conductive

traces on a substrate like a flex circuit or PCB (Figure 1-2).

The charge flows are absorbed by the touch of a human

finger (Figure 1-3) resulting in a decrease in coupling from X

to Y. Thus, received signals decrease or go negative with

respect to the reference level during a touch.

Water films cause the coupled fields to increase slightly,

making water films easy to distinguish from touch.

1.2 Circuit Model

An electrical circuit model is shown in Figure 1-5. The

coupling capacitance between X and Y electrodes is

represented by Cx. While the reset switch is open, a sample

switch is gated so that it transfers charge flows only from the

rising edge of X into a charge integrator. On the falling edge

of X, the switch connects the Y line to ground to allow the

charge across Cx to neutralize to zero. The voltage change

on the output of the charge integrator after each X edge is

quite small, on the order of a few tens of millivolts. Changes

due to touch are typically under 0.1% of total integrator

voltage. The X pulse can be

repeated in a burst of up to 64

pulses to increase the change in

integrator output voltage due to

touch during an acquire (Section

3.6) to increase gain.

The charge detector is an opamp

configured as an integrator with a

reset switch; this creates a virtual

ground input, making the Y lines

appear low impedance when the

sample switch is closed. This

configuration effectively

eliminates cross-coupling among

Y lines while greatly lowering

susceptibility to EMI. The circuit

is also highly immune to

capacitive loading on the Y lines,

since stray C from Y to ground

appears merely as a small

parallel capacitance across a

virtual ground.

The circuit uses an 8-bit ADC,

with a subranging structure to

effectively deliver a 14-bit total

conversion 'space' (see Figure

1-6 and Section 3.3). In this way

the circuit can tolerate very large

www.qprox.com

QT60xx5 / R1.05

Figure 1-3 Field Flows When Touched

Figure 1-4 Fields With a Conductive Film

overlying panel

element

Figure 1-2 Sample Electrode Geometries

PARALLEL LINES SERPENTINE SPIRAL

Figure 1-1 Field flow between X and Y elements

overlying panel

element

elem ent

absolute signals yet still respond to very small signal

changes. Subranging is provided by two offset mechanisms

which can be thought of as 'coarse' and 'fine' offsets.

The 'coarse' method uses one or two switched Cz capacitors

to subtract charge from the charge integrator to create up to

two step offsets, to bring the analog signal back to a more

reasonable level. This action occurs during the course of the

burst.

The 'fine' method of offset uses an 8-bit R2R ladder DAC

driven by the X drive lines to create an offset in the amplifier

stage. The DAC is driven after the burst has ceased and the

charge accumulated, so there is no conflict in this dual-use of

the X lines.

Short sample gate dwell times after the X

edges will limit the effect of moisture

spreading from key to key by taking

advantage of the RC filter-like nature of

continuous films; a short dwell time will limit

the time that the charge has to travel

through the impedance of the film (Section

3.13). This effect is independent of the

frequency of burst repetition, intra-burst

pulse spacing, or X drive pulse width.

Burst mode operation permits reduced

power consumption and reduces RF

emissions, while permitting excellent

response time.

1.3 Matrix Configuration

The matrix scanning configuration is shown

in Figure 1-5. The ‘X’ drives are sequentially

pulsed in groupings of bursts; an 8:1 analog

mux acts as the sample switch for all ‘Y’

lines. At the intersection of each ‘X’ and ‘Y’

line in the matrix itself, where a key is

desired, should be an interdigitated electrode set similar to

those shown in Figure 1-2. The outermost electrode or the

key border should always be connected to an ‘X’ drive;

flooding the area around keys with X fill to a width of up to

10mm can help in suppressing moisture films further.

Although it is referred to as a ‘matrix’, there is no restriction

on where individual keys can be located. The term ‘matrix’

refers to the electrical configuration of keys, not the physical

arrangement. Consult Quantum for application assistance on

key design.

1.4 Communications

The device uses two variants of SPI communications,

Slave-only and Master-Slave. Over this interface is a

command and data transfer structure

designed for high levels of flexibility using

minimal numbers of bytes. For more

information see Sections 4 and 5.

Device variations: Refer to Section 3.1 for

differences between the parts covered by

this datasheet.

2 Signal Processing

The devices calibrate and process all

signals using a number of algorithms

specifically designed to provide for high

survivability in the face of adverse

environmental challenges. They provide a

large number of processing options which

can be user-selected to implement very

flexible, robust keypanel solutions.

2.1 Negative Threshold

See also Command ^R, page 29

‘MS’ pin 37 can output a positive pulse oscilloscope sync that

brackets the burst of a selected key. This feature is controlled

by the ^R command. More than one burst can output a sync

pulse, for example if the scope of the command when set is

a row or column, or is all keys. The ^R command is volatile

and does not survive reset or power down.

This feature is invaluable for diagnostics; without it, observing

signals clearly on an oscilloscope for a particular burst is

nearly impossible.

This pin is also used as a SPI mode select pin. In order to

prevent a shorted output when the oscilloscope sync is

enabled, the MS pin should only be connected to ground or

Vdd via a m10K resistor.

This function is supported in QmBtn PC software via a

checkbox.

3.21 Power Supply and PCB Layout

Vdd should be 5.0 volts +/- 5%. This can be provided by a

common 78L05 3-terminal regulator. LDO type regulators are

usually fine but can suffer from poor transient load response

which may cause erratic signal behavior.

If the power supply is shared with another electronic system,

care should be taken to assure that the supply is free of

digital spikes, sags, and surges which can adversely affect

the circuit. The devices can track slow changes in Vcc

depending on the settings of drift compensation, but signals

can be adversely affected by rapid voltage steps and impulse

noise on the supply rail.

0.1µF bypass caps from power to ground should be used

near every supply pin of every active component in the circuit.

Vee is a negative supply used by the circuit of Figure 3-1; it

can range from -3V to -5V. It does not need to be regulated

but should be well filtered and free from external fluctuations.

Figure 3-1 shows a simple, inexpensive charge-pump which

is driven from resonator pin XTO to generate Vee.

Current requirements of the circuit are approximately

20mA / Vdd, 4mA / Vee when running.

PCB layout: The PCB layout should incorporate a ground

plane under the entire circuit; this is possible even with

2-layer boards. The ground plane should be broken up as

little as possible. Internal nodes of the circuit can be quite

sensitive to external noise and the circuit should be kept

away from stray magnetic and electric fields, for example

those emanating from mains power components such as

transformers and power capacitors. If proximity to such

components is unavoidable, an electrostatic shield should be

considered. The Sync feature (Section 3.17) can also be

invaluable in reducing these types of noise sources.

Sample layout artwork is available from Quantum on request.

www.qprox.com

QT60xx5 / R1.05

3.22 ESD / Noise Considerations

In general the QT60xx5 will be well protected from static

discharge during use by the overlying panel. However, even

with a dielectric panel transients currents can still flow into

scan lines via induction or in extreme cases, dielectric

breakdown. Porous or cracked materials may allow a spark to

tunnel through the panel. In all cases, testing is required to

reveal any potential problems. The devices have diode

protected pins which can absorb and protect the device from

most induced discharges, up to 5mA.

The X lines are not usually at risk during operation, since they

are low-resistance output drives. The YCn lines are not

directly connected to the matrix and so are not at risk.

However the PLD and the QS3251 are connected to the Y

lines and may require additional ESD protection.

Diode clamps can be used on the X and Y matrix lines. The

diodes should be high speed / high current types such as

BAV99 dual diodes, connected from Vdd to Vss with the

diode junction connected to the matrix pin.

Capacitors placed on the X and Y matrix lines can also help

to a limited degree by absorbing ESD transients and lowering

induced voltages. Values up to 100pF can be used without

causing circuit problems.

The circuit can be further protected by inserting series

resistors into the X and/or Y lines to limit peak transient

current. Values up to 500 ohms can be used in most cases,

but if the dwell time is short this resistance can cause a

reduction in signal gain. RC networks as shown in Figures

4-4 and 4-5 can provide enhanced protection against ESD

while also limiting the effects of external fields.

External field interference can occur in some cases; these

problems are highly dependent on the interfering frequency

and the manner of coupling into the circuit. PCB layout

(Section 3.21) and external wiring should be carefully

designed to reduce the probability of these effects occurring.

Of particular note is the length of the connection from the

circuit to the key panel. This connection will act as an

antenna that will resonate at various radio frequencies to

cause interference, and thus should be very short. If RFI

pickup is a problem, the connections should be damped

using ferrite beads or low-value (22 - 100 ohm) series

resistors in all lines including any ground and power lines

running in parallel to the panel.

SPI data noise: In some applications the host MCU can be

some distance from the sensor, with the interface coupled via

ribbon cable. The SPI link is particularly vulnerable to noise

injection on these lines; corrupted or false commands can be

induced from transients on the power supply or ground wiring.

Bypass capacitors and series resistors can be used to

prevent these effects as shown in Figures 4-4 and 4-5.

4 Serial Interface

QT60xx5 devices use an SPI serial interface to a host MCU.

This port uses a protocol described in Section 5.

4.1 Serial Port specifications

QT60xx5's use an SPI synchronous serial interface with the

following specifications at 6MHz oscillator frequency:

Max clock rate, Fck 1.5MHz

Data length 8 bits

Host command space, Tcm m 50µs

Response delay to host, Tdr1 Table 4-1, also, Sec. 7

Drdy delay from response, Tdr2 1µs to 1ms

Multi-byte return spacing, Tdr3 15µs to 2ms

The host can clock the SPI at any rate up to and including the

maximum clock rate Fck. The maximum clock rate of the part

in Master mode is determined by Setup ^Q.

The part can operate in either master-slave mode or

slave-only mode, and is thus compatible with virtually all

SPI-capable microcontrollers.

The SPI interface should not be used over long distances due

to problems with signal ringing and introduced noise etc.

unless suitably buffered or filtered with RC networks as

shown in Figures 4-4 and 4-5. Slower data rates with longer

RC timeconstants will provide enhanced resistance to noise

and ringing problems.

Conversion to asynchronous UART format can be

accomplished by using a microcontroller with conversion

firmware. Using such a conversion device the part can

communicate with Quantum's QmBtn PC software. Consult

Quantum for details.

4.2 Protocol Overview

The SPI protocol is based entirely on polled data

transmission, that is, the part will not send data to the host of

its own volition but will do so only in response to specific

commands from the host.

Run-time data responses, such as key detection or error

information, requires simple single-byte functions to evoke a

response from the part.

Setup mode interactions mostly use 2-byte functions from the

host to cause the part to alter its behavior; these functions

also cause writes to the internal eeprom.

The concept of 'scope' is used to allow functions to operate

on individual keys or groupings of keys. The scope of

subsequent functions can be altered by short initial scope

instructions.

See Section 5 for protocol details.

4.3 SPI Slave-Only Mode

Refer to Figures 4-1 and 4-2. Select Slave-only by

floating Pin 37 (MS) or tying high via a m10K resistor. Pin

37 also functions as an oscilloscope sync output (Section

3.20) and should never be tied directly to a supply rail. In

Slave mode the host must always be in Master mode, as

it controls all SPI activity including clocking of the

www.qprox.com

QT60xx5 / R1.05

Figure 4-1 SPI Connections

Slave-Only Master-Slave

MOSI MOSI

MISOMISO

SCK SCK

DRDY

P_OUT

P_IN

Host M

T60

MSVdd

MOSI MOSI

SCK SCK

DRDY

Host MCU QT60

MISOMISO

10K

interface in both directions. Unlike hardware SPI slaves,

QT60xx5's need processing time to respond to functions.

DRDY’ is used to let the host know when data is ready for

collection; it indicates to the host when data is ready in

response to a command so that the host can clock over the

data.

This mode requires 5 signals to operate:

MOSI - Master out / Slave in data pin; used as an input for

data from the host at all times. This pin should be

connected to the MOSI pin of the host device.

MISO - Master in / Slave out data pin; used as an output for

data to the host at all times. This pin should be connected

to the MISO pin of the host device.

SCK - SPI clock - input only clock pin from host. The host

must shift out data on the falling edge of SCK; the

QT60xx5 clocks data in on the rising edge of SCK.

Important note: SCK must idle low just before and after

SS’ transitions either up or down, or the transmission will

fail; between bytes SCK should always idle low. SCK

should never float.

SS’ - Slave select - input only; acts as a framing signal to the

sensor from the host. SS’ must be low before and during

reception of data from the host. It must not go high again

until SCK line has returned low; during data or echo

response it must not go high until after the host has

sensed that DRDY’ has gone high from the device. SS’

must idle high. SS’ has an internal pullup resistor.

DRDY’ - Data Ready - active-low - indicates to the host that

the part is ready to send data back subsequent to a

command from the host. This pin idles high. The DRDY’

pin has an internal pullup resistor inside.

Internal pullup resistors note: The internal pullup resistors

can range from 35k to 120k ohms. If RC filtering is used on

the SPI lines per Figure 4-4, this resistance may not be low

www.qprox.com

QT60xx5 / R1.05

Table 4-1 Typical DRDY (Tdr1) Response Delays (Burst Length = 12)

300us300us300us300us300us400us

All other commands

800us800us800us800us1ms1ms

Get key errors (E), Get keys pushed (K)

2ms2ms2.5ms2.5ms2.7ms3ms

Calibrate command (all keys)

800ms800ms800ms800ms800ms800ms

Lock Reference Levels ('L') command

300ms300ms300ms300ms300ms300ms

Setup - Put (affect 64 keys)

40ms40ms40ms40ms40ms40ms

Setup - Put (affect 8 keys)

10ms10ms10ms10ms10ms10ms

Setup - Put (affect 1 key)

2ms1ms500µs400µs300µs250µsFunction Type

Burst Spacing

Figure 4-2 SPI Slave-Only Mode Timing

SCK

{from host}

MOSI

{from host}

MISO

{from sensor}

Invalid Data

Optional Byte 2Host Command Byte 1 Null Dummy Data Null Dummy Data

Invalid Data Response Data or Echo Nth Response Data

{

}

DRDY

{from sensor}

{from host}

7 6543210

7 6543210 7 6543210

7 6543210

7 6543210 7 6543210

Tdr1

cm Tdr2

dr3

Figure 4-3 SPI Master/Slave Mode Timing

SCK

MOSI

Optional Byte 2

from host to sensor

Command Byte 1

from Host to sensor

Tdr1

Response Byte or Echo

from sensor to host

Nth Byte from sensor

{N = command dependent}

SS, SCK, MOSI originate from Host SS, SCK, MOSI originate from sensor

7 6543210 7 6543210 7 6543210 7 6543210

Floating

cm Tdr3

enough to ensure adequate signal risetime and may need to

be augmented with external 10k pullups.

The host must wait until DRDY’ goes low before an SPI

transfer to retrieve data. For multi-byte responses, the host

must observe DRDY' to see when it goes high again after

each data byte, then low again, before executing another

transfer to get the next data byte. The host should send null

bytes (0x00) to retrieve data.

If the DRDY’ line does not go low after a command, the

command was not properly received or it was inappropriate.

The delay to DRDY’ low depends on how many bytes of data

are being loaded into eeprom; Table 4-1. Absolute worst case

delays are found in Section 7; these timings occur only rarely,

for example if the device happens to be busy with adjacent

key suppression calculations, which occurs only at the

moment when a key is first detected.

A typical Slave-only function sequence is as follows:

1) The host pulls SS’ low, then transfers a command to the

sensor. The host then releases SS’ to float high. DRDY’ is

unaffected in this step.

2) For 2-byte functions, (1) is repeated with a m50µs delay.

3) When the sensor has the command echo or requested

data ready to send back to the host, it loads it into its SPI

4) The host detects that the sensor has pulled DRDY’ low

and in turn the host pulls SS’ low.

5) The host obtains the byte from the sensor by transmitting

a dummy byte (0x00) to the sensor.

6) The sensor releases DRDY’ to float high.

7) After the host detects that DRDY' has floated high the

host must allow SS’ to also float high.

8) For multi-byte responses, steps (3) through (7) are

repeated until the return data is completely sent.

The host must release the SS’ line in step (7) even between

multiple byte responses because the QT60xx5 waits for the

SS’ line to return high before signalling that the next byte is

ready for collection.

The host should check the DRDY’ line and wait for it to go

high before transmitting another byte. Until the DRDY’ line is

released the sensor is still processing a data return, even if

the complete response data has been fully transferred; the

sensor may still be busy when the host finishes the byte

transfer and may not be able to digest a new command

immediately.

See Section 3.18, page 15, for a description of the Alert pin

which can be used to reduce communication traffic.

4.4 SPI Master-Slave Mode

Refer to Figures 4-1 and 4-3. In Master-Slave mode the host

and sensor take turns being Master; the host always initiates

in Master mode during an exchange. The current Master

always controls all 3 signals. The sensor takes a variable

amount of time to respond to the host, depending on the

function and current and pending tasks. SPI Master/Slave

mode is selected by tying Pin 37 (MS) low via a 10K resistor.

Pin 37 is also an oscilloscope sync output (see Section

3.20 and command ^R, page 29) and should never be tied

directly to either supply rail. The host, like the sensor, must

idle in slave mode when not sending a command.

Master/Slave requires 3 signals to operate:

MOSI - Master out / Slave in data pin - bidirectional - an input

pin while the host is transmitting data; an output when the

sensor is transmitting data. The MOSI of the host and

slave should be tied together. The MISO lines are not used

on either part and should be left open.

SCK - SPI clock - bidirectional - an input pin when receiving

data; an output pin when sending. The host must shift out

data on the falling edge of SCK; the QT60xx5 clocks data

in on the rising edge of SCK. Important note: SCK from

the host must be low before asserting SS’ low or high at

either end of a byte or the transmission will fail. SCK

should idle low; if in doubt, a 10K pulldown resistor should

be used. When the sensor returns data it becomes the

Master; data is shifted out by it on the falling edge of SCK

and should be clocked in by the host on the rising edge.

SS’ - Slave select - bidirectional framing control. When the

sensor is in slave mode, this pin accepts the SS’ control

signal from the host. In either data direction, SS' must go

low before and any during data transfer; it should not go

high again until SCK has returned low at the end of a byte.

www.qprox.com

QT60xx5 / R1.05

Figure 4-4 Filtering SPI Slave-Only Connections

Figure 4-5 Filtering SPI Master-Slave Connections

MOSI

MISO

SCK

DRDY

QT60xx5 Circuit

220

47pF Ra

RESET

Host MCU

100

22pF

Xn X drives

(1 of 8

shown)

Y Lines

(1 of 8

shown)

10K

1nF

10K

SCK

MISO

MOSI

(MS not

shown)

P_IN

P_OUT1

P_OUT2

MOSI

MISO

SCK

DRDY

QT60xx5 Circuit

220

47pF Ra

RESET

Host MCU

100

22pF

Xn X drives

(1 of 8

shown)

Y Lines

(1 of 8

shown)

1nF

10K

MOSI

SCK

MISO

(MS not

shown)

P_OUT

1nF2,20046.875kHz

470pF2,20093.75kHz

270pF1,000375kHz

100pF6801.5MHz

CaRaSPI Clock Rate

Recommended Values of Ra & Ca for Figures 4-4 and 4-5

In Master mode the sensor asserts control over this line, to

make the host a slave and to frame the data. This line

must idle high; the part includes an internal pullup resistor

and should be floated during idle times.

Internal pullup resistor note: The internal pullup resistor on

SS’ can range from 35k to 120k ohms. If RC filtering is used

on the SPI lines per Figure 4-5, this pullup resistance may not

be low enough to ensure adequate signal risetime and may

need to be augmented with external 10k pullups.

A command may consist of one or two bytes with a m50µs

delay between bytes. At the end of a full command, the host

must go into Slave mode to await a response.

The sensor may take some time to process the command

and respond. When it does, it asserts SS’ low and begins

clocking data out. For multi-byte responses, bytes will be sent

at intervals which may be irregular depending on the request

and the processing load of the sensor. The host must be

prepared to accept the sensor data as it comes or there can

be a data overrun in the host. If the data returns too quickly

for the host to accept it, lower the SPI clock rate.

A typical Master-Slave function sequence is as follows:

1) Host enters Master mode. The sensor is already in Slave

mode.

2) The host pulls SS’ low, then transfers one byte of

command to the sensor via MOSI, then releases SS’ to

float high again.

3) For 2-byte functions, (2) is repeated with m50µs spacings

between bytes.

4) The host immediately places its SPI port into Slave mode,

floating SCK and MOSI’; SS’ stays floating.

5) When the sensor has a command echo or data to send

back, it puts its SPI register in Master mode, taking control

over MOSI and SCK. SS' remains floating.

6) The sensor pulls SS’ low, then clocks out its response

byte to the host, then floats SS’ high again.

7) The sensor repeats (6) as necessary for multiple byte

responses.

8) The sensor returns to slave mode.

After the transmission sequence, the SPI lines float high or

are left to float in an indeterminate state (MOSI) until the next

transmission sequence is initiated by the host. The host

should wait for m1ms after a sequence before initiating

another transmission sequence.

See Section 3.18, page 15, for a description of the Alert pin

which can be used to reduce communication traffic.

4.5 Sensor Echo and Data Response

The devices respond to each and every valid command from

the host with at least one return byte. In the case of functions

that do not send data back to the host, the part returns the

command itself as an echo, but only after the function has

been completed; this also holds for 2-byte functions where

the second byte is an operand: in these cases the return byte

is an echo of the command, not the operand.

Exception: The recalibration command ‘b’ returns an

acknowledgement immediately rather than just before the

actual recalibration.

Commands that return data do not send back a command

echo. If desired, the command can be verified via the 'l'

(lowercase L) echo function; see page 28.

The host should not transmit a new command until the

last command has been processed and responded to

completion, plus 1ms.

Commands that are not recognized are ignored, and the host

should monitor for timeouts to detect these conditions. If this

occurs a new command should not be sent until the specified

timeout duration has expired.

The maximum timings shown in Table 4-1 and Section 7-5

are guaranteed provided that the part is operating within the

timing limitations of Section 5.7. If burst timing is in violation,

the response time to a command may be longer.

4.6 Eeprom Corruption

The device stores its Setup data in an internal eeprom which

can be readily altered via Put mode commands. Sometimes

noise on Vdd, the SPI lines or Reset pin can cause eeprom

corruption which can be difficult or inconvenient to correct.

The device should always be left in Get mode to prevent

spurious commands from corrupting the eeprom. The Get

command should ideally be repeated every second or so to

ensure that if noise on the SPI lines causes a false Put mode

command that it does not last long. Preferably, the ‘l’

command (lowercase ‘L’) should be used to verify that the Put

command has succeeded.

Flash backup: The part backs up the entire eeprom array

into onboard Flash rom after one or more Setup write

commands have been issued and the part is then reset.

During normal operation the part constantly compares the

Flash area with the eeprom array to ensure the two sections

match. If an eeprom error is detected, the device sets an

error flag (bit 4) in the general device status byte (Command

‘7’, page 22) which can be read by the host device. The LED

output also becomes active. If the bit 4 error flag is set, the

host should immediately induce a device reset.

Bit 4 is also set if an intentional write has been made to

eeprom, but not yet copied into Flash via the reset process. It

is perfectly acceptable to continue altering any number of

Setup parameters prior to doing the reset, ignoring this bit.

During power up or after a reset, the device compares the

Flash area with eeprom, and if there is a discrepancy the

eeprom is refreshed from Flash, unless an intentional write

was detected in which case the Flash is updated from the

eeprom. As intentional writes in Put mode should only occur

during manufacture, it is normally safe to assume that

eeprom changes during normal run mode are errors.

The host can also periodically test the checksum of the

eeprom as a backup mechanism to the bit 4 error flag.

The uppercase ‘L’ command, Lock Reference Levels, also

writes data to eeprom, and this data also has the potential to

become corrupted. This data is also backed up in Flash so

that it can be recovered, and an error in this data will also set

bit 4 and also alter the checksum. Also, the ‘L’ command only

operates if the device is in Put mode as a further protection.

Flash rom has a limit of 1,000 write cycles, so copy-to-Flash

should not be used routinely.

www.qprox.com

QT60xx5 / R1.05

5 Commands & Functions

The command structure is designed to minimize control and

data traffic. All repetitive data and status commands from the

host are single-byte, and most commands result in single-

byte device responses. Behavioral setup commands involve

multiple bytes but these are infrequently used.

Special 'scope' commands exist to restrict subsequent

commands to a specific key or range of keys. This control

structure permits most matrix keys, which are usually

identical in shape and size, to be programmed 'in bulk' using

a 'global' scope command, followed by a scope restriction to

specific key(s), followed by more key programming, to

prevent the need for tedious key-by-key programming across

an entire matrix.

There are four types of commands:

Direction - Determine whether subsequent commands are

used to get data from or put data to the part;

Scope - Restrict the range of effect of subsequent

commands to a specific set of keys;

Status - Cause the part to respond with key information,

such as detections, signals, error codes, and the like;

Setup - Modify functionality such as burst length, threshold

levels, drift compensation characteristics, etc.

Supervisory - Special functions such as diagnostics,

calibration, etc. which affect the part as a whole.

All command types can be intermixed. Even during normal

device operation it is possible to use Setup and Supervisory

functions to alter key behavior on the fly. There is no special

'setup mode'.

Get/Put, Scope, and many Supervisory functions are volatile

and do not persist after a power down or reset cycle. Some

Supervisory commands require that the part be reset in order

for the new settings to take effect.

Note that the Setup functions write to eeprom and require

extra time for a response back to the host. Also note that as

with all eeprom memories there is a recommended lifetime

limit to the number of writes; this limit is 100,000 cycles.

Command functions are summarized in Section 5-6

It is highly advised to test the device checksum

(command ‘6’) or individual key settings or the general

device status (‘7’) once Setups have been programmed

into the part, each time the part is powered up and

periodically while running.

The part backs up all eeprom locations into Flash

memory, from which data is restored automatically

following a reset if eeprom corruption is detected. The

part should also be reset after any Put command(s) in

order to force the copy of eeprom data into Flash. See

Section 4.6.

5.1 Direction Commands

Setup commands can be used to either send control

information to the part for programming into its internal

eeprom, or to extract the current setting of this information.

The same Setup function can do either. To accomplish this

the device relies on direction control via the Get and Put

commands. In Get mode, a Setup command will return

information. In Put mode, the behavior of the device is

altered, and often a second operand byte must be sent.

The powerup or reset default mode is Get. The current

Get/Put mode persists until countermanded by a different

Get/Put command or until the device is reset or powered off.

It is advisable to use Put mode only when actually writing

Setups to the device, which will happen infrequently; the part

should normally be left in Get mode. Get mode acts as a lock

to prevent accidental changes to the internal eeprom.

Multiple direction commands of the same type (g, g, g, g ...)

are harmless and can be used to insure that the part does not

accidentally enter Put mode for a prolonged period, for

example due to noise glitches on the SPI lines. The 'g'

command can be repeated every few seconds.

g 0

67 - G

OMMAND

n/an/an/an/aGet

0x67n/a1n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Lowercase 'G'. The 'g' command causes the device to treat all

subsequent Setup commands as 'Gets'; after, when a Setup

command is received from the host the part will respond by

sending back the current status of that Setup parameter.

The 'g' command is always single-byte and echoes back

itself.

p 0

70 - P

OMMAND

n/an/an/an/aGet

0x70n/a1n/aPut

Returns2nd Byte RangeBytes / CmdScope

Lower case 'p'. The 'p' command causes the device to treat

all subsequent Setup commands as 'Puts'; after, when a

2-byte Setup command is received from the host the part will

respond by programming in the desired parameter for the

key(s) which are affected.

The 'p' command is always single-byte and echoes back

itself.

www.qprox.com

QT60xx5 / R1.05

5.2 Scope Commands

The host should always set the scope parameter when

initializing the part during normal operation as well as during

setup. Scope commands are persistent and apply to all

subsequent functions that are affected by scope, until a

different scope command is issued. On powerup or after reset

the device defaults to scope = 'all keys'.

Many functions only address one key regardless of the

current scope; in these cases the key being addressed is

always the key last set by the 's' or 'x' and 'y' commands. If

the 's' command was last set to key #9 (x=1, y=1), then even

though the 'S' command was issued afterwards the one-key

scope will remain key '9'. If 'x' were subsequently set to 2 then

one-key scope will be key x=2, y=1 (key #10). If 'y' were

subsequently set to 3, then one-key scope will be key x=2 /

y=3 (key #26). This rule operates for commands in either Put

or Get modes.

Key numbering convention: The numbering of keys goes by

row then column. For example, the key in row X=3, column

Y=1 (X3Y1) is key 11. The formula for conversion of an X-Y

location to a key number is:

key_number = X_row + (Y_column x 8)

Row and column numbers are per Fig. 1-6. Keys are acquired

in this same burst sequence, i.e. X0Y0, X1Y0, X2Y0 etc.

s 0

73 - S

PECIFIC

COPE

n/an/an/an/aGet

0x730x00..0x3F2n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Lowercase 'S'. Targets a specific individual key for all further

functions that are affected by scope. The second byte must

contain a binary key number from 0..63 decimal.

S 0

53 - A

EYS

COPE

n/an/an/an/aGet

0x53n/a1n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Uppercase 'S'. Addresses all keys in the matrix for all further

functions that can target a group of keys.

x 0

78 - R

EYS

COPE

n/an/an/an/aGet

0x780x00..0x072n/aPut

Returns2nd Byte RangeBytes / CmdScope

Lowercase 'X'. Targets keys in a specific row for functions

that can address key groups. The second byte must contain a

row number from 0..7. This command also affects scope for

single-key commands.

y 0

79 - C

OLUMN

EYS

COPE

n/an/an/an/aGet

0x790x00..0x072n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Lowercase 'Y'. Targets keys in a specific column for functions

that can address key groups. The second byte is a binary

column number from 0..7. This command also affects scope

for single-key commands.

5.3 Status Commands

Status commands cause the sensor to report back

information related to keys and their signals.

It is not necessary to set the part to Get mode with these

commands, although it is advised to leave the part in Get

mode as a normal precaution (see Section 5.1)

0 0

30 - S

IGNAL

FOR

INGLE

0x00..0xFF111Get

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Numeric '0'. Returns the signal level in 8-bit unsigned binary

for one key whose location is determined by scope. Note that

the signal level is inverted: decreasing values correspond to

more touch due to the physics of key detection described in

Section 1.1.

1 0

31 - D

ELTA

IGNAL

FOR

INGLE

0x00..0xFF111Get

n/an/an/an/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Numeric '1'. Returns the value {Reference - Signal} in

unsigned 8-bit binary for one key whose location is

determined by scope. If Signal > Reference, the result is

truncated to zero.

Increasing amounts of this value correspond to increasing

amounts of touch as the sign of signal is inverted (see 0x30

above).

2 0

32 - R

EFERENCE

ALUE

0x00..0xFF111Get

n/an/an/an/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Numeric '2'. Returns the Reference value in unsigned 8-bit

binary for one key whose location is determined by scope.

3 0

33 - R2R O

FFSET

0x00..0xFF111Get

n/an/an/an/aPut

Returns# Bytes RtndBytes / CmdScope

Section 1.2, p. 4

Numeric '3'. Returns the R2R offset value in unsigned 8-bit

binary for one key whose location is determined by scope.

This function is useful primarily for circuit diagnostics or for an

independent determination of proper circuit operation.

4 0

34 - C

TATE

0x00..0x02111Get

n/an/an/an/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Section 1.2, p. 4

Numeric '4'. Returns the Cz state for one key whose location

is determined by scope. This function is useful primarily for

circuit diagnostics or for an independent determination of

circuit operation after calibration. A higher value indicates

more Cz cancellation is being applied to compensate for Cx;

a value of 2 indicates both Cz caps are being switched in.

www.qprox.com

QT60xx5 / R1.05

5 0

35 - D

ETECTION

NTEGRATOR

OUNTS

0x00..0xFF111Get

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Numeric '5'. Returns the Detection Integrator counter value

for one key whose location is determined by scope. This

function is useful primarily for circuit diagnostics.

6 0

36 - E

EPROM

HECKSUM

0x00..0xFF11n/aGet

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Numeric '6'. Returns the entire eeprom checksum. This

function is useful primarily for diagnostics and should

periodically be used to check for valid eeprom contents.

The checksum should be computed when the entire device's

settings, including the locked reference levels ('L' command)

are set. The host can then periodically test the checksum to

validate eeprom integrity. If needed, the eeprom can then be

reprogrammed by the host or the device can be reset to allow

the eeprom to be updated from Flash ROM (see Section 4.6).

The checksum is a simple 8-bit carry fold-back type. Changes

to multiple Setups can generate identical checksums.

Changes to one location only will always produce a different

checksum. An identical change to 2, 4, 8, 16, 32 or 64 keys is

more prone to generating an identical checksum. A unique

checksum can be obtained again by altering any Setup for

another key (i.e. an unused key) to be different.

After any Setups change, the checksum will not be valid until

after the device has been reset.

Note that the general status byte returned by the ‘7’

command contains a bit that is set if there is an error in

eeprom data; this feature operates independently of the

checksum command.

There is no put version of the command.

7 0

37 - G

ENERAL

EVICE

TATUS

0x00..0x1F11n/aGet

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Section 2.12, p. 8

Numeric '7'. Returns the part's general status byte which is a

5-bit pattern as follows:

KDKRKESFEFuuu

b0b1b2b3b4b5b6b7

KD: 1= one or more keys are in detection

KR: 1= one or more keys are recalibrating

KE: 1= one or more keys are reporting errors

SF: 1= sync fail; the part is not synchronized to an

external source (if in that mode; see Section 3.17).

EF: 1 = Eeprom / Flash discrepancy (Section 4.6)

Higher bits (‘u’) report as 0's and are not used.

This command can be used as a general 1-byte status

response; if one or more bits are set, the host can take

interrogate further to narrow down specifics, such as which

key is being touched or in error, via other commands.

> 0

20 - S

IGNAL

EVELS

FOR

ROUP

0x00..0xFF8 or 6418, 64Get

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Space character. Same function as 0x30 above except

returns a group response of 8 bytes (if Scope = row or

column selected) or 64 bytes (if Scope = entire matrix

selected). If no group scope has been selected, returns data

for all keys (64 bytes).

! 0

21 - D

ELTA

IGNALS

FOR

ROUP

0x00..0xFF8 or 6418, 64Get

n/an/an/a n/aPut

Returns# Bytes RtndBytes / CmdScope

Exclamation character. Same function as 0x31 above except

returns a group response for 8 or 64 keys depending on

current scope. If no group scope has been selected, returns

data for all keys (64 bytes).

" 0

22 - R

EFERENCE

EVELS

FOR

ROUP

0x00..0xFF8 or 6418, 64Get

n/an/an/an/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Double quote character. Same function as 0x32 above except

returns a group response of 8 or 64 bytes depending on

current scope. If no group scope has been selected, returns

64 bytes.

# 0

23 - R2R O

FFSET

FOR

ROUP

0x00..0xFF8 or 6418, 64Get

n/an/an/an/aPut

Returns# Bytes RtndBytes / CmdScope

Hash character. Same function as 0x33 above except returns

a group response of 8 bytes (Scope = row or column

selected) or 64 bytes (Scope = entire matrix selected)

depending on the current group scope setting. If no group

scope has been selected, returns 64 bytes.

$ 0

24 - C

HARGE

ANCELLATION

FOR

ROUP

0x00..0x038 or 6418, 64Get

n/an/an/a n/aPut

Returns# Bytes RtndBytes / CmdScope

Dollar character. Same function as 0x34 above except returns

a group response of 8 bytes (Scope = row or column

selected) or 64 bytes (Scope = entire matrix selected)

depending on the current group scope setting. If no group

scope has been selected, returns 64 bytes.

% 0

25 - D

ETECT

NTEGRATOR

OUNTS

FOR

ROUP

0x00..0xFF8 or 6418, 64Get

n/an/an/an/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Percent character. Same function as 0x35 above except

returns a group response of 8 bytes (Scope = row or column)

or 64 bytes (Scope = entire matrix) depending on the current

group scope setting. If no group scope has been selected,

returns 64 bytes.

www.qprox.com

QT60xx5 / R1.05

e 0

65 - E

RROR

ODE

FOR

ELECTED

0x00..0x0F111Get

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Section 2.12, p. 8

Lowercase 'E'. Returns the error byte for a selected key

defined by the 's' command. A 4-bit pattern is returned:

FRHLuuuu

b0b1b2b3b4b5b6b7

F: 1= failed last full recalibration attempt

R: 1= key is in process of full recalibration

H: 1= key reference is high (above normal bounds)

L: 1= key reference is low (below normal bounds)

u: undefined

Refer also to Section 2.10.

F, Bit 0 is set if it failed to calibrate properly during a forced

recalibration. The sensor will automatically make 5 sequential

attempts at recalibration before setting this flag.

R, Bit 1 is set if the key is in the process of a full

recalibration. When set, bits 2 and 3 are immediately cleared.

H, Bit 2 when set indicates either:

- the reference has drifted above decimal 191, or,

- the total absolute reference level has become higher than

the upper window boundary described in Section 2.11

and as defined by Command ^N after a forced

recalibration.

L, Bit 3 when set indicates either:

- the reference has drifted below decimal 64, or,

- the total absolute reference level has become lower than

the lower boundary described in Section 2.11, as defined

by Command ^O after a forced recalibration.

Bits 2 and 3, if set via drift compensation, would indicate that

the key should be recalibrated by the host. If H and L bits

appear immediately after a full recalibration, it means that the

key is probably defective.

E 0x45 - Error Codes for Group

0x00..0xFF1 or 811, 8, 64Get

n/an/an/a n/aPut

Returns# Bytes RtndBytes / CmdScope

Section 2.12, p. 8

Uppercase 'E'. Returns general error codes for a range of

keys defined by scope. Returns either 1 or 8 bytes depending

on whether a single key, row, column, or entire matrix are

selected.

The bitfields for a single key are the same as for 'e' above.

The bitfields for a single row (X) are:

0Y1Y2

3Y4Y5Y6Y7

b0b1b2b3b

b6b7

The bitfields for a single column (Y) are:

X0X1X2X3X4X5X6X7

b0b1b2b3b4b5b6b7

The bitfields for a global response are:

X1Y7

X2Y7

X3Y7

X4Y7

X5Y7

X6Y7

X7Y7

te8

X1Y6

X2Y6

X3Y6

X4Y6

X5Y6

X6Y6

X7Y6

te7

X0Y5

X1Y5

X2Y5

X3Y5

X4Y5

X5Y5

X6Y5

X7Y5

byte6

X0Y4

X1Y4

X2Y4

X3Y4

X4Y4

X5Y4

X6Y4

X7Y4

byte5

X0Y3

X1Y3

X2Y3

X3Y3

X4Y3

X5Y3

X6Y3

X7Y3

byte4

X0Y2

X1Y2

X2Y2

X3Y2

X4Y2

X5Y2

X6Y2

X7Y2

te3

X0Y1

X1Y1

X2Y1

X3Y1

X4Y1

X5Y1

X6Y1

X7Y1

te2

X0Y0

X1Y0

X2Y0

X3Y0

X4Y0

X5Y0

X6Y0

X7Y0

te1

b0b1b2b3b4b5b6b7

Byte 1 is the first returned byte in the sequence.

In all the above examples a '1' in a bit position indicates that

there is some type of error associated with the key. The use

of the 'e' command (or 'E' with scope set to a specific key) will

specify the nature of the error.

k 0

6B - R

EPORTING

IRST

OUCHED

0x00..0xFF11n/aGet

n/an/an/a n/aPut

Returns#Bytes RtndBytes / CmdScope

Section 2.12, p. 8

Lowercase 'K'. Returns a byte that indicates which if any key

has been touched. The byte is structured as follows:

k0k1k2k3k4k5-m

b0b1b2b3b4b5b6b7

Bits are used as follows:

m - if '1', indicates that yet another key is active

k0..k5 - indicates the key number of a first detected key,

in the range 0..63 (0x00..0x3F).

If a reported key drops out while other keys are active, 'k' will

report one of the other active keys, but there is no rule for

which of the next keys gets reported in k0..k5.

If the byte returned has a value of 255 (0xFF), then no key

has been detected.

www.qprox.com

QT60xx5 / R1.05

K 0

4B - K

OUCH

EPORTING

FOR

ROUP

0x00..0xFF1 or 811, 8, 64Get

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Section 2.12, p. 8

Uppercase 'K'. Returns 1 or 8 bytes depending on the current

scope. The byte(s) returned contain a bit pattern which

indicates touched keys. A scope of a single key, row or

column will return one byte. A scope of all keys will return 8

bytes. If scope is one key, only the LSB is used to report.

The bitfields for a single key are:

key-------

b0b1b2b3b4b5b6b7

The bitfields for a single row (scope is X) are:

0Y1Y2

3Y4Y5Y6Y7

b0b1b2b3b

b6b7

The bitfields for a single column (scope is Y) are:

X0X1X2X3X4X5X6X7

b0b1b2b3b4b5b6b7

The bitfields for a global report are:

X1Y7

X2Y7

X3Y7

X4Y7

X5Y7

X6Y7

X7Y7

te8

X1Y6

X2Y6

X3Y6

X4Y6

X5Y6

X6Y6

X7Y6

te7

X0Y5

X1Y5

X2Y5

X3Y5

X4Y5

X5Y5

X6Y5

X7Y5

te6

X0Y4

X1Y4

X2Y4

X3Y4

X4Y4

X5Y4

X6Y4

X7Y4

byte5

X0Y3

X1Y3

X2Y3

X3Y3

X4Y3

X5Y3

X6Y3

X7Y3

byte4

X0Y2

X1Y2

X2Y2

X3Y2

X4Y2

X5Y2

X6Y2

X7Y2

byte3

X0Y1

X1Y1

X2Y1

X3Y1

X4Y1

X5Y1

X6Y1

X7Y1

te2

X0Y0

X1Y0

X2Y0

X3Y0

X4Y0

X5Y0

X6Y0

X7Y0

te1

b0b1b2b3b

b6b7

Byte 1 is the first returned byte in the sequence.

In all the above examples a '1' in a bit position indicates that

the key is touched; a '0' indicates no touch.

5.4 Setup Commands

Setup functions are those that alter the behavior a key or a

group of keys. The setups are programmed into eeprom

locations in the part and ordinarily do not need to be

reprogrammed once set. However it is possible to change a

setup while the device is in normal operation without

interrupting the sensing function of the part.

Setup functions alter the internal eeprom, and this requires a

much longer time to complete than other commands; see

Table 4-1.

Setup 'put' commands become effective immediately after the

echo response of the command byte unless otherwise noted;

some setups require that the key(s) being altered be

recalibrated with the 'b' command before they take effect.

^A 0

01 - N

EGATIVE

ETECT

HRESHOLD

0x04..0x40n/a11Get

0x010x04..0x4021, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.1, p. 5

Ctrl-A. In Put mode, the command followed by a setting is

programmed into eeprom for the key(s) affected by scope.

1, 8, or 64 keys may be affected. Valid decimal values are:

45678101215

17 20 25 30 35 45 55 64

Values other than the above will be rounded down.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

This setup controls key sensitivity by setting the counts of

signal delta needed to cause a detect. Higher = less

sensitive. Numbers should be 6 or greater under most

conditions to reduce the probability of noise detection.

Numbers greater than 20 indicate that the burst length is

probably too high. This setup interacts with Burst Length (^F).

^B 0

02 - P

OSITIVE

ETECT

HRESHOLD

0x04..0x40n/a11Get

0x020x04..0x4021, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.2, p. 6

Ctrl-B. In Put mode, the command followed by a setting is

programmed into eeprom for the key(s) affected by scope. 1,

8, or 64 keys may be affected. Valid decimal values are:

45678101215

17 20 25 30 35 45 55 64

Values other than the above will be rounded down.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

This setup controls the ability of a key to recalibrate quickly

should the signal transition positive quickly, as when a touch

is prolonged enough to cause a recalibration, and when the

key is then 'untouched'. This condition can also be caused by

a foreign object being removed from a key. The value should

normally be set between 6 and 10 counts. If the value is very

high, the key will still recover by means of the drift

compensation process, albeit more slowly.

www.qprox.com

QT60xx5 / R1.05

^C 0

03 - N

EGATIVE

HRESHOLD

YSTERESIS

0x01..0x03n/a164Get

0x030x01..0x03264Put

Return

te 2 Ran

tes / Cm

Scop

Section 2.3, p. 6

Ctrl-C. In Put mode, the command followed by a setting is

programmed into eeprom for all keys only. The value should

be from 0 to 3, representing hysteresis as follows:

0: 50%

1: 25%

2: 12.5%

3: 0% (no hysteresis)

Values other than the above will be rounded down.

The percentage is the distance from the threshold level to the

reference level. The hysteresis level is always closer to the

threshold point than to the reference point. 25% is a

reasonable value under most conditions.

As this parameter is common to all keys, Put and Get

operations send or return only one byte.

^D 0

04 - P

OSITIVE

HRESHOLD

YSTERESIS

0x01..0x03n/a164Get

0x040x01..0x03264Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.3, p. 6

Ctrl-D. Identical in operation to ^C above except this applies

to positive 'detections' used to recalibrate the sensor (see ^B

above for details). Uses same hysteresis values as ^C above.

05 - D

WELL

IME

ACHINE

YCLES

0x01n/a164Get

0x050x01264Put

ReturnsByte 2 RangeBytes / CmdScope

Sections 1.2, 3.3, 3.9, 3.13

Ctrl-E. Governs the delay from the rise of an X drive to the

termination of Y transfer gating ('dwell time').

This command is included for compatibility with future

versions. The device defaults to 1 (one) machine cycle of

dwell or 167ns with a 6MHz oscillator. Although the command

will be accepted, this setting cannot be changed.

The dwell time can be shortened below 167ns by an external

circuit as described in Section 3.9.

As this parameter is common to all keys, Put and Get

operations send or return only one byte, 0x01.

06 - B

URST

ENGTH

0x00..0x40n/a11Get

0x060x00..0x4021, 8, 64Put

Return

te 2 Ran

tes / Cm

Scop

Section 3.6, p. 12

Ctrl-F. In Put mode the command sets the burst length of one

or more keys, according to the current scope. Valid decimal

values are:

012345710

12 15 20 25 30 40 50 64

Values other than the above will be rounded down.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

^F sets the length of the acquisition burst on a key by key

basis. This setting is directly proportional to signal gain. This

setup interacts with Negative and Positive Threshold (^A and

^B). Increasing ^F can allow for higher threshold levels and

more robust signals, at the expense of increased radiated

emissions and reduced Cx load capacity.

Special condition: If the value for ^F for a key is set to zero

the burst disabled and the key will not function; the key will

report back with an error code. The timing for the 'phantom

burst' will be preserved so that overall key scan timing will

remain unchanged.

^G 0

07 - B

URST

PACING

0x00..0x05n/a164Get

0x070x00..0x05264Put

Return

te 2 Ran

tes / Cm

Scop

Section 3.8, p. 12

Ctrl-G. In Put mode, sets the spacing between successive

acquire bursts for the entire matrix.

The second byte indicates the spacing to be set according to

the following values:

0: 250µs

1: 300µs

2: 400µs

3: 500µs

4: 1000µs

5: 2000µs

Values higher than the above will be truncated to 2000µs.

Longer delay times equate to slower acquisitions. At lower

delay times (faster rep rates) there can be conflicts with long

burst lengths which will prevent proper operation; see Section

5.7.

The time required to scan the entire keymatrix once is the

above delay multiplied by 64 regardless of the number of

keys actually used or the part model number.

Burst spacing also affects recalibration time; see Section 2.10

The scope for this function is always 'all keys'.

www.qprox.com

QT60xx5 / R1.05

^H 0

08 - N

EGATIVE

RIFT

OMPENSATION

ATE

0x01..0x64n/a11Get

0x080x01..0x6421, 8, 64Put

Return

te 2 Ran

tes / Cm

Scop

Section 2.4, p. 6

Ctrl-H. In Put mode, sets the rate of drift compensation used

in the negative signal direction.

The second byte must be one of the following valid values

(shown in decimal):

1234681012

15 20 25 33 45 60 75 100

Values other than the above will be rounded down.

These numbers correspond to the amount of drift

compensation applied, in 100ms/count of reference change,

for signals which are negative with respect to the reference

level, i.e. in the same direction as legitimate detections.

Higher numbers equate to slower drift compensation.

Overcompensation (too fast) can result in the suppression of

legitimate detections. Under-compensation can result in

inadequate compensation for rapid environmental changes.

Values of 15 to 45 (1.5 to 4.5 secs/count) are considered

normal under most conditions.

Drift compensation does not occur while the signal has

passed below the ^A threshold level or subsequently

remained below the negative hysteresis level.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

Put mode scope can be one key, a row or column, or all keys.

^I 0

09 - P

OSITIVE

RIFT

OMPENSATION

ATE

0x01..0x64n/a11Get

0x090x01..0x6421, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.4, p. 6

Ctrl-I. Same as ^H above in all respects, except operates

only when the signal is positive with respect to the reference

level, i.e. in an abnormal direction. It is usually desirable to

set this rate much faster than for ^H, i.e. to a lower number.

Valid decimal values are:

1234681012

15 20 25 33 45 60 75 100

Values other than the above will be rounded down.

Values of 4 to 10 (0.4 to 1.0 secs/count) are considered

suitable for most systems.

Positive drift compensation continues to operate even if the

signal has exceeded the positive threshold.

^J 0x0A - D

ETECT

NTEGRATOR

IMIT

0x00..0xFFn/a11Get

0x0A0x00..0xFF21, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.6, p. 7

Ctrl-J. In Put mode, sets the detect integrator limit for one or

more keys according to scope.

The unit of measure is a burst, i.e. a setting of 5 means that a

detection must be sensed 5 bursts in sequence. A burst for a

key occurs once every complete matrix scan. Thus, if the

burst spacing is 500us, the response time will be:

5 x 500us x 64 = 160ms

The second byte must be one of the following values (shown

in decimal):

0123571015

20 32 45 60 90 123 175 255

Values other than the above will be rounded down.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

This setup can be used as a noise filter, or as a mechanism

to intentionally slow down key reaction time in order to require

a long user touch.

Special condition: If the value for ^J is set to zero the key is

disabled, but the burst for the key is still generated.

^K 0x0B - P

OSITIVE

ECALIBRATION

ELAY

0x00..0xFFn/a11Get

0x0B0x00..0xFF21, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.7, p. 7

Ctrl-K. In Put mode, sets the delay until recalibration, timed

from when the signal first crosses the positive threshold.

The second byte controls the delay in 100ms increments, and

must be one of the following valid values:

0123571015

20 32 45 60 90 123 175 255

Values other than the above will be rounded down. As an

example, a value of 85 will cause a 6-second delay.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

Special condition: If ^K is set to zero this feature is disabled

and the key will never auto-recalibrate on positive transitions;

however drift compensation will still operate.

^L 0x0C - N

EGATIVE

ECALIBRATION

ELAY

0x00..0xFFn/a11Get

0x0C0x00..0xFF21, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.5, p. 6

Ctrl-L. In Put mode, sets the delay until recalibration, timed

from when the signal first crosses below the negative

threshold as defined by ^A.

The second byte represents the delay in 1s increments, and

must be one of the following valid values:

0123571015

20 32 45 60 90 123 175 255

Values other than the above will be rounded down. As an

example, a setting of 85 will cause delays of 60 seconds.

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

www.qprox.com

QT60xx5 / R1.05

Special condition: If the value for ^L is set to zero this

feature is disabled and the key will never auto-recalibrate

after a prolonged touch.

^M 0x0D - I

NTRA

-B

URST

ULSE

PACING

0x02..0x0An/a164Get

0x0D0x02..0x0A264Put

Return

te 2 Ran

tes / Cm

Scop

Section 3.7, p. 12

Ctrl-M. In Put mode, sets the amount of time between

individual pulses in a burst.

The second byte must be in the range of 2 to 10 decimal;

other values will be ignored. The setting applies to all keys.

The value corresponds to the timing between pulses within a

burst, in microseconds. For example, a setting of 5 will set the

pulse spacing to 5 microseconds.

In Get mode the function returns the current value of ^M.

Intra-burst pulse spacing controls the fundamental frequency

of the burst and can have a strong effect on radiated

emissions from the matrix control panel. It can also have an

effect on susceptibility to external EMI if the external fields are

close in periodicity to the burst spacing.

^N 0x0E - P

OSITIVE

EFERENCE

RROR

AND

0x00..0x64n/a164Get

0x0E0x00..0x64264Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.8, p. 7

Ctrl-N. In Put mode, sets the amount of tolerable positive

deviation in the reference level for all keys, in percent, with

regard to the 'locked' reference value for each key. The setup

is global in nature and affects all keys equally.

Valid values are from 0 to 100 decimal; higher values will be

truncated to 100. The percentage applied is 10x the decimal

value, thus, a value of 100 equates to a 1,000% change (i.e.

10x the locked reference level).

In Get mode the function returns the current setting of ^N.

This setup is used to define the limit of possible positive

reference deviation with respect to a factory setting, which is

used in turn to set an error flag for key(s) whose reference

level rises above the designated error band. If for example

this setting is set to 50, and the device is calibrated and

reference levels are locked (see command 'L', Lock

Reference Levels) into the part by the OEM, then in the future

if the reference level of a key should rise 500% over its

Locked reference level then the key will report back an error

flag via commands 'e' or 'E'.

To obtain the error flag for a boundary condition, the key must

be first recalibrated using the 'b' command.

The host device should periodically check the reference

levels for keys to make sure they do not rise above 191 or fall

below 64 (see Section 2.11); if this should happen the host

should recalibrate the affected key(s). Failure to do so will

prevent the error band limits from operating.

The error band can be used to detect circuit faults as well as

extremes of temperature or moisture on the circuitry. Typical

values are from 2 to 4 (20% to 40%).

Special condition: If the value is set to zero, this feature is

disabled.

^O 0x0F - N

EGATIVE

EFERENCE

RROR

AND

0x00..0x63n/a164Get

0x0F0x00..0x63264Put

Return

te 2 Ran

tes / Cm

Scop

Section 2.8, p. 7

Ctrl-O. In Put mode, sets the amount of tolerable negative

deviation in the reference level for all keys, in percent with

regard to the 'locked' reference value for each key. The setup

is global in nature and affects all keys equally.

Valid values are from 0 to 99 decimal; higher values will be

truncated to 99. The percentage applied is equal to the

decimal value; a value of 99 equates to 99% of the signal

level (i.e. a 1% decrease w.r.t. the locked reference level).

In Get mode the function returns the current setting of ^M.

This setup is identical in nature to ^N except that: (1) it

governs negative reference deviations, and (2) values are

expressed in percent instead of 10's of percent.

Special condition: If the value is set to 0, this feature is

disabled.

^P 0x10 - A

DJACENT

UPPRESSION

(‘AKS’)

0x00, 0x01n/a11Get

0x100x00, 0x0121, 8, 64Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.9, p. 8

Ctrl-P. In Put mode, instructs logic for the keys specified by

the current scope whether or not to enable the AKS feature.

Valid 2nd byte values for this function are:

0: AKS off {default}

1: AKS on

In Get mode, the command will return a single byte according

to the rules of Section 5.2, page 21.

AKS functions to suppress detections from water films which

can 'spread' a touch signal from the touched key to adjacent

keys. It is also useful for panels with tightly spaced keys,

where a fingertip can partially overlap an adjacent key. This

feature will act to suppress the signals from the unintended

keys.

AKS only operates across keys that have been AKS-enabled;

signal strength comparisons are not made with non-

AKS-enabled keys.

Unused keys with burst lengths of zero are also ignored for

purposes of AKS.

www.qprox.com

QT60xx5 / R1.05

5.5 Supervisory / System Functions

Supervisory functions report or control miscellaneous

functions that affect overall chip control, testing, or

diagnostics. All supervisory functions ignore scope except

where noted.

For commands requiring Put mode to operate, the device

should be set back to Get mode immediately thereafter where

possible, to help prevent unintended writes to eeprom.

6 0

36 - E

EPROM

HECKSUM

0x00..0xFF11n/aGet

n/an/an/a n/aPut

Return

# B

tes Rtn

tes / Cm

Scop

See page 22.

D 0

44 - DAC T

EST

n/an/an/an/aGet

0x440x00..0xFF2n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Uppercase 'D'. Enables the DAC test mode function. The

second byte contains the value to be sent to the DAC, which

must be sent within 100ms to the part otherwise the

command is automatically cancelled. The part must be in Put

mode for this command to work.

This function can be used to test the external R2R DAC for

proper operation during board production or in development.

Once in this mode the part ceases to operate as a sensor,

and must be reset via power-down or the reset pin to restore

normal operation. This function does not persist past reset or

power-down.

Before the DAC value is set in hardware, the burst length on

all keys is set to 0 to disable keys and prevent further

scanning. All keys will then report errors until all burst lengths

are again set by the host after the part has been reset.

A series of 'D' commands can be sent to cause the DAC to

generate a ramp or other test pattern which can be easily

diagnosed on an oscilloscope.

There is no get version of the command.

L 0x4C - L

OCK

EFERENCE

EVELS

n/an/an/an/aGet

0x4C0x00264Put

Returns2nd Byte RangeBytes / CmdScope

Section 2.8, p. 7

Uppercase 'L'. This is a put-only command that locks the

reference levels of the device into eeprom for all keys, for

boundary checking purposes over the product's life.

The whole command – 'L' followed by a null (0x00) - must be

received within 100ms without any intervening byte, or the

command will fail. The part must be in Put mode for this

command to work.

The scope of this command is always 'all keys'.

This function records to eeprom the Cz values, DAC offset,

and signal reference. The locked reference levels are used to

compute boundary checks; these are performed after the next

device recalibration or reset.

Due to the large number of bytes written to eeprom by this

command, there is a significant delay from the second byte

until the return echo is sent back to the host.

This command should be used only during production. There

is no get version of the command.

b 0x62 - R

ECALIBRATE

EYS

n/an/an/an/aGet

0x62n/a11, 8, 64Put

Returns2nd Byte RangeBytes / CmdScope

Section 2.10, p. 8; Section 3.16

Lowercase 'B'. This is a put-only command that causes the

keys selected by scope to recalibrate. The part must be in Put

mode for this command to work.

The return byte is sent before the keys have calibrated. While

keys are in recalibration, status of the keys can be

determined using the 'e' or 'E' commands.

If 'b' is sent while key(s) are already in the middle of

recalibration, the affected key(s) will abandon the old

calibration cycle and start a new one.

There is no get version of the command.

l 0x6C - R

ETURN

AST

OMMAND

HARACTER

0x00..0xFF11n/aGet

n/an/an/an/aPut

Returns# Bytes RtndBytes / CmdScope

Lowercase 'L'. This get-only command reports back with the

value of the prior command received by the part. The

command also reports back any erroneous commands,

allowing the host device to verify that a command was

correctly received.

If this command is repeated, the second and subsequent

instances of 'l' will report back with 0x6C.

There is no put version of the command.

r 0x72 - R

ESET

EVICE

n/an/an/an/aGet

0x720x002n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Section 3.14, p. 14

Lowercase 'R'. This put-only command hard-resets the part.

The command 0x72 must be followed by a null (0x00) within

100ms or the command will fail. The part must be in Put

mode for this command to work.

After the null byte is received, the device will echo back the ‘r’

character; about 16ms after the echo the part will reset.

Upon waking up again, the part will resume communication

and sensing in accordance with the timing shown in Section

3.16.

If for some reason the device is unable to echo back the ‘r’

character, for example due to the host not releasing the SS

line, the part will completely reset anyway after about 2

seconds.

There is no get version of the command.

www.qprox.com

QT60xx5 / R1.05

V 0x56 - R

ETURN

ART

ERSION

0x00..0xFF11n/aGet

n/an/an/an/aPut

Return

# B

tes Rtn

tes / Cm

Scop

Uppercase 'V'. This get-only command returns the part

version number.

There is no put version of the command.

W 0x57 - R

ETURN

ART

IGNATURE

0x20, 0x30, 0x4011n/aGet

n/an/an/an/aPut

Returns# Bytes RtndBytes / CmdScope

Section 3.1, p. 9

Uppercase 'W'. This get-only command returns the part

signature as follows:

0x20 (32 decimal) - for QT60325

0x30 (48 decimal) - for QT60485

0x40 (64 decimal) - for QT60645

There is no put version of this command.

Z 0x5A - E

NTER

LEEP

n/an/an/an/aGet

*0x5A, 0x5A0x002n/aPut

Returns2nd Byte RangeBytes / CmdScope

Section 3.17, p. 14

Uppercase 'Z'. This put-only command forces the device to

enter sleep mode. The command 0x5A must be followed only

by a null (0x00) within 100ms or the command will fail.

The command returns 0x5A immediately before going to

sleep, and a second 0x5A upon waking up. The part must be

in Put mode for this command to work.

If for some reason the device is unable to echo back the first

‘Z’ character, for example due to the host not releasing the

SS line, the part will completely reset after about 2 seconds.

The part will reawaken after a logic low is detected for >10µs

on pin 11 (X2WS pin, see Section 3.17, p. 14). The device

then sends the second ‘Z’ back to the host, and resumes

from its prior state before it went to sleep without the need for

recalibration.

The device always reawakens in Get mode.

There is no get version of the ‘Z’ command.

^Q 0x11 - D

ATA

ATE

ELECTION

0x00..0x03n/a1n/aGet

0x110x00..0x032n/aPut

Return

2nd B

te Ran

tes / Cm

Scop

Section 4, p. 16

Ctrl-Q. This command sets the communications clock rate of

the SPI interface in Master mode. The acceptable values of

the 2nd byte are:

0: 46.875 kHz {factory default}

1: 93.75 kHz

2: 375 kHz

3: 1.5 MHz

The part must be in Put mode for this command to work.

Note that when the part is in Slave mode, the host can clock

data to the device at rates up to 1.5MHz even if the setting of

^Q is slower.

New settings do not become effective until the device has

been powered off and back on again or after the reset (‘r’)

command.

Refer to Sections 4.3 and 4.4 for specific timing details.

^R 0

12 - O

SCILLOSCOPE

YNC

0x00, 0x01n/a11, 8, 64Get

0x120x00, 0x0121, 8, 64Put

Return

2nd B

te Ran

tes / Cm

Scop

Section 3.20, p. 15

Ctrl-R. In Put mode, controls the oscilloscope sync function

of Pin 37. The settings of this function are:

0: off {factory default}

1: on

When on, Pin 37 outputs a pulse that brackets the acquire

burst(s) for the keys targeted by scope. Without this it is

virtually impossible to view signals corresponding to a specific

key.

Pin 37 idles low and pulses high during a sync pulse. Pin 37

is also used for SPI mode selection by connecting to +5 or

Ground, and as a result if ^R is used, Pin 37 should never

be clamped to a supply rail but rather connected via a 10K

resistor to prevent a short circuit. See Section 3.20.

^R is volatile, that is, it does not persist after a power down.

^S 0x13 - C

LAMP

OLARITY

0x00, 0x01n/a1-Get

0x130x00, 0x012-Put

Returns2nd Byte RangeBytes / CmdScope

Section 3.19, p. 15

Ctrl-S. Controls the polarity of the Cs Clamp line, CSR, pin

35, using the 2nd byte as follows:

0: active-low

1: active-high

The part must be in Put mode for this command to work.

This pin controls the polarity of the reset signal applied to the

charge integrator reset switch. In systems using an n-channel

switch (active-high required to reset the Cs capacitor), this

option should be set to ‘1’; for a p-channel mosfet switch in

bipolar supply systems requiring an active-low to reset the Cs

capacitor, ^S should be set to ‘0’. For the reference circuit of

Figure 3-1 this should be set to ‘0’ (the default); for the circuit

of Figure 3-2 this should be set to ‘1’..

The setting of ^S does not become effective until the device

has been powered off and back on again or after the reset

(‘r’) command has been issued.

www.qprox.com

QT60xx5 / R1.05

^T 0x14 - B

OUNDARY

ONSTANT

C1, MSB

0x00..0x7Fn/a164Get

0x140x00..0x7F264Put

Return

te 2 Ran

tes / Cm

Scop

Section 2.8, p. 7

Ctrl-T. In Put mode, sets the MSB of equation constant C1

for boundary checking purposes. The part must be in Put

mode for this command to work.

The function has global scope. The default value is 5, which

corresponds to the reference circuit on page 10. A change in

this parameter only has effect after a reset or recalibration of

all keys.

Valid values are from 0 to 127 decimal. Each count of the

MSB has a value 256x that of the LSB.

In Get mode this function returns the current ^T value.

Refer to ^U (0x15) for the LSB definition.

^U 0x15 - B

OUNDARY

ONSTANT

C1, LSB

0x00..0xFFn/a164Get

0x150x00..0xFF264Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.8, p. 7

Ctrl-U. In Put mode, sets the LSB of equation constant C1 for

boundary checking purposes. The part must be in Put mode

for this command to work.

The function has global scope. The default value is 0xE9,

which corresponds to the reference circuit on page 10. A

change in this parameter only has effect after a reset or

recalibration of all keys.

Valid values are from 0 to 255 decimal. The value of the LSB

must be combined with the value of the MSB to form the total

value.

In Get mode this function returns the current ^U value.

Refer to ^T (0x14) for the MSB definition.

^V 0x16 - B

OUNDARY

QUATION

ONSTANT

0x00..0xFFn/a164Get

0x160x00..0xFF264Put

ReturnsByte 2 RangeBytes / CmdScope

Section 2.8, p. 7

Ctrl-V. In Put mode, sets equation constant C2 for boundary

checking purposes. The part must be in Put mode for this

command to work.

This function has global scope. The default value is 8, which

corresponds to the reference circuit on page 10. A change in

this parameter only has effect after a reset or recalibration of

all keys.

Valid values are from 0 to 255 decimal.

In Get mode this function returns the current ^V value.

^W 0x17 - N

OISE

YNC

0x00, 0x01n/a1-Get

0x170x00, 0x012-Put

Return

te 2 Ran

tes / Cm

Scop

Section 3.17, p. 14

Ctrl-W. In Put mode, sets whether the noise sync feature is

enabled or disabled. The part must be in Put mode for this

command to work.

The settings are:

0: off {factory default}

1: on

This function has global scope. The default value is 0 (off).

This feature can be used to synchronize the part to an

external repetitive source of e-field which might interfere with

the sensor signals, for example 50 or 60Hz fields from

adjacent power wiring. By doing so the part becomes immune

to the noise source.

In Get mode this function returns the current setting of ^W.

The setting of ^W does not become effective until the device

has been powered off and back on again or after the reset

(‘r’) command has been issued.

www.qprox.com

QT60xx5 / R1.05

5.6 Function Summary Table

24-0x00..0xFF1, 8, 641, 8, 64Gget indication of all touched keysreport touches for group0x4BK

23-0x00..0xFF--Gget indication of first touched keyreport 1st key0x6Bk

0x00..0xFF1, 8, 641, 8, 64Gget error bits for group error codes for group0x45E

0x00..0x0F11Gget error code for 1 keyerror code for 1 key0x65e

0x00..0xFF8, 648, 64Gget detection integrators for group Det integrator for group0x25%

0x00..0x028, 648, 64Gget Cz states for group Cz states for group0x24$

0x00..0xFF8, 648, 64Gget R2R offsets for group R2R offset for group0x23#

0x00..0xFF8, 648, 64Gget References levels for group references for group0x22“

0x00..0xFF8, 648, 64Gget Reference-Signal for group delta signals for group0x21!

0x00..0xFF8, 648, 64Gget signal for group signals for group0x20<sp>

0x00..0x1F1-Gget device status of entire devicegeneral device status0x377

0x00..0xFF1-Gget eeprom checksum of entire eepromeeprom checksum0x366

0x00..0xFF11Gget detect integrator for 1 key Det Integrator for 1 key0x355

0x00..0x0211Gget Cz value for 1 key Cz state for 1 key0x344

0x00..0xFF11Gget R2R Offset for 1 key R2R offset for 1 key0x333

0x00..0xFF11Gget Reference level for 1 key reference for 1 key0x322

0x00..0xFF11Gget Reference-Signal for 1 key delta signal for 1 key0x311

0x00..0xFF11Gget signal for 1 key signal for 1 key0x300

Status Commands

undefined

0x790x00..0x072-Ptargets keys in a designated column, range 0..7Set column keys scope0x79y

undefined

0x780x00..0x072-Ptargets keys in a designated row, range 0..7Set row keys scope0x78x

undefined

0x531-Ptargets all keys in the matrixSet all keys scope0x53S

undefined

0x730x00..0x3F2-Ptargets a specific key in range 0..63Set one key scope0x73s

Scope Commands

Get

0x701-Pall subsequent Setups become 'Puts’Put0x70p

Get

0x671-Pall subsequent Setups become 'Gets'Get0x67g

Direction Commands

Return

range

Bytes

returned

ScopeReturns

Operand

Range

Bytes/PutScope Page

Default

setting

Get ModePut Mode

P/GDescriptionNameHexChar

31 www.qprox.com

QT60xx5 / R1.05

270 (off)0x00, 0x01110x100x00, 0x0121, 8, 64P/Gadjacent key suppression feature; 1 = onKey suppression0x10^P

270 (off)0x00..0x631640x0F0x00..0x63264P/G

tolerable negative reference deviation with respect to

Locked reference values, step 1%. Zero disables.

Neg error band0x0F^O

270 (off)0x00..0x641640x0E0x00..0x64264P/G

tolerable positive reference deviation with respect to

Locked reference values, step 10%. Zero disables.

Pos error band0x0E^N

270x020x02..0x0A1640x0D0x02..0x0A264P/G

period of QT pulses, in microseconds

2, 3, 4, 5, 6, 7, 8, 9, 10us

Intra-burst spacing0x0D^M

260x64 (10s)0x00..0xFF110x0C0x00..0xFF21, 8, 64P/G

time req’d to tri

er a recal from a detection, in 1s

increments. Zero disables recal.

0,1,2,3,5,7,10,15,20,32,45,60,90,123,175,255 secs

Neg recal delay0x0C^L

260x0A (1s)0x00..0xFF110x0B0x00..0xFF21, 8, 64P/G

time req’d to trigger a recal from a positive signal

excursion in 0.1s increments; zero disables recal.

0,.1,.2,.3,.5,.7,1,1.5,2,3.2,4.5,6,9,12.3,17.5,25.5 secs

Pos recal delay0x0B^K

260x030x00..0xFF110x0A0x00..0xFF21, 8, 64P/G

number of detections required to register a touch,

counted in bursts of detection; zero disables a key.

0,1,2,3,5,7,10,15,20,32,45,60,90,123,175,255 counts

Neg det int limit0x0A^J

260x0A (1s)0x01..0x64110x090x01..0x6421, 8, 64P/G

rate of drift compensation for positive signal swings

.1,.2,.3,.4,.6,.8,1,1.2,1.5,2,2.5,3.3,4.5,6,7.5,10 secs

Pos drift comp rate0x09^I

260x1E (3s)0x01..0x64110x080x01..0x6421, 8, 64P/G

rate of drift compensation for ne

ative si

nal swin

.1,.2,.3,.4,.6,.8,1,1.2,1.5,2,2.5,3.3,4.5,6,7.5,10 secs

Neg drift comp rate0x08^H

0x01

(300us)

0x00..0x051640x070x00..0x05264P/G

time from start of one burst to start of next burst

250us, 300us, 400us, 500us, 1000us, 2000us

Burst spacing0x07^G

250x0C0x01..0x40110x060x00..0x4021, 8, 64P/G

set

ain via number of QT c

cles / burst; zero disables

burst

0,1,2,3,4,5,7,10,12,15,20,25,30,40,50,64

Burst length0x06^F

250x010x011640x050x01264P/G

delay from the rise of an X line to end of Y-gate;

only setting is 0x01 (167ns/period @ 6MHz Xtal)

Dwell time0x05^E

250x01 (25%)0x00..0x03110x040x00..0x03264P/G

hysteresis for positive threshold

50%, 25%, 12.5%, 0%

Positive hysteresis0x04^D

250x01 (25%)0x00..0x03110x030x00..0x03264P/G

hysteresis for negative threshold

50%, 25%, 12.5%, 0%

Negative hysteresis0x03^C

240x080x04..0x40110x020x04..0x4021, 8, 64P/G

sensitivit

to positive si

nals for recalibration

4,5,6,7,8,10,12,15,17,20,25,30,35,45,55,64 counts

Positive threshold0x02^B

240x0C0x04..0x40110x010x04..0x4021, 8, 64P/G

touch sensitivit

threshold; less = more

4,5,6,7,8,10,12,15,17,20,25,30,35,45,55,64 counts

Negative threshold0x01^A

Setup Commands

Return

range

Bytes

returned

ScopeReturns

Operand

Range

Bytes/PutScope Page

Default

setting

Get ModePut Mode

P/GDescriptionNameHexChar

32 www.qprox.com

QT60xx5 / R1.05

300 (off)0x00, 0x011-0x170x00, 0x012-P/G

noise sync enable; 1 = on

device must be reset to take effect

Noise sync0x17^W

300x080x00..0xFF1640x160x00..0xFF264P/Gboundary equation constant, C2Boundary C20x16^V

300xE90x00..0xFF1640x150x00..0xFF264P/Gboundary equation constant, C1, LSBBoundary C1 LSB0x15^U

300x050x00..0x7F1640x140x00..0x7F264P/Gboundary equation constant, C1, MSBBoundary C1 MSB0x14^T

2900x00, 0x011-0x130x00, 0x012-P/G

Cs clamp drive polarit

; 0 = active-low; part must be

reset via ‘r’ command or hard reset to take effect

Cs clamp0x13^S

290 (off)0x00, 0x011-0x120x00, 0x0121, 8, 64P/G

oscilloscope sync control. 1 = on.

feature is volatile - cleared to 0 after each reset

Scope sync0x12^R

290 (46.8k)0x00..0x031-0x110x00..0x032-P/G

sets SPI master-mode clock rate. Part must be reset via

‘r’ command or hard reset to take effect

46.875kHz, 93.75kHz, 375kHz, 1.5MHz

SPI rate0x11^Q

29-0x5A, 0x5A0x002-P

force device into Sleep mode. ‘Z’ must be followed by a

null within 100ms. 0x5A returned before and after

entering Sleep

Sleep0x5AZ

29-

0x20, 0x30,

0x40

1-Greturns part signature numberSignature0x57W

29-0x00..0xFF1-Greturns part version numberVersion0x56V

28-0x720x002-P

hard reset the device. ‘r’ must be followed b

a null

within 100ms.

Reset device0x72r

28-0x00..0xFF1-Gsend back last command byte receivedReturn last command0x6Cl

28-0x6211, 8, 64P

fully recalibrate keys;

return byte is sent prior to calibration

Recal keys0x62b

28-0x4C0x00264P

locks reference levels into eeprom for future boundary

checks. ‘L’ must be followed by 0x00 (null) 100ms after

the command byte

Lock references0x4CL

28-0x440x00..0xFF2-P

sends operand to R2R DAC; b

te 2 must be sent within

100ms of command byte

DAC test0x44D

0-0x00..0xFF1-Greturns checksum of internal eepromEeprom checksum0x366

Supervisory Commands

Return

range

Bytes

returned

ScopeReturns

Operand

Range

Bytes/PutScope Page

Default

setting

Get ModePut Mode

P/GDescriptionNameHexChar

33 www.qprox.com

QT60xx5 / R1.05

5.7 Timing Limitations

The device requires processing time between bursts, as well

as time to handle communications with the host. With short

burst spacings, long burst lengths, and long intra-burst pulse

spacings, the device can simply run out of available

processing time. When this happens, burst timing and host

communications can slow down and become erratic.

Burst spacings should be verified on an oscilloscope during

development to be certain that the device timings are

preserved and are constant. If not, the burst length and/or

pulse spacing should be reduced.

www.qprox.com

QT60xx5 / R1.05

Table 5-2 Permissible Burst Lengths (BL’s)

642,000642,000642,000642,000

401,000401,000501,000501,000

30500305003050040500

20400204002540030400

10300123001230015300

5250725072507250

Max BL

Burs

Spacing

Max BL

Burs

Spacing

Max BL

Burs

Spacing

Max BL

Burs

Spacing

Pulse Spacin

= 10µsPulse Spacin

= 9µsPulse Spacin

= 8µsPulse Spacin

= 7µs

642,000642,000642,000642,000642,000

641,000641,000641,000641,000641,000

5050050500645006450064500

3040040400404004040064400

1530020300203002030050300

725010250102501025025250

Max BL

Burst

Spacing

Max BL

Burst

Spacing

Max BL

Burst

Spacing

Max BL

Burst

Spacing

Max BL

Burst

Spacing

Pulse Spacin

= 6µsPulse Spacin

= 5µsPulse Spacin

= 4µsPulse Spacin

= 3µsPulse Spacin

= 2µs

6 PLD Source Listing

Pre-programmed parts are available from Quantum in small quantities.

The object code file for this PLD is also available upon request.

TITLE 'E664SPI'

Description

Timing skew generator for E664SPI matrix board. Code is for ICT PEEL22CV10AZ epld. Not warranted to work with any other part.

Compiler and documentation from the ICT web site, www.ictpld.com.

Programmer from System General; model “All Writer”, www.systemgeneral.com.

End_Desc;

PEEL22CV10A

"I/O CONFIGURATION DECLARATION

"IOC (PIN_NO 'PIN_NAME' POLARITY OUTPUT_TYPE FEEDBACK_TYPE)

"Inputs

Y0 PIN 5 "pre-decoded Y inputs

Y1 PIN 4

Y2 PIN 3

Y3 PIN 2

Y4 PIN 8

Y5 PIN 9

Y6 PIN 10

Y7 PIN 11

XS PIN 1 "Sum of X1..X7

X7 PIN 6 "X7 input (gets OR'd with XS)

YG PIN 7 "Y gate trigger

"Outputs

"Clamping outputs

IOC ( 21 'YM0' Pos Com Feed_Pin )

IOC ( 19 'YM1' Pos Com Feed_Pin )

IOC ( 17 'YM2' Pos Com Feed_Pin )

IOC ( 15 'YM3' Pos Com Feed_Pin )

IOC ( 16 'YM4' Pos Com Feed_Pin )

IOC ( 18 'YM5' Pos Com Feed_Pin )

IOC ( 20 'YM6' Pos Com Feed_Pin )

IOC ( 22 'YM7' Pos Com Feed_Pin )

"Dly ckt drive out

IOC ( 14 'XSD' Pos Com Feed_Pin )

"QS3251 neg enable

IOC ( 23 'YGG' Pos OutCom Feed_Pin )

AR NODE 25 "Global Asynchronous Reset

SP NODE 26 "Global Synchronous Preset

DEFINE

EQUATIONS

AR = 0;

SP = 0;

" Define Y clamp outputs

YM0.COM = 0;

YM1.COM = 0;

YM2.COM = 0;

YM3.COM = 0;

YM4.COM = 0;

YM5.COM = 0;

YM6.COM = 0;

YM7.COM = 0;

"Enable control. Goes low on active Y channel (Y= active high to clamp)

YM0.OE = Y0;

YM1.OE = Y1;

YM2.OE = Y2;

YM3.OE = Y3;

YM4.OE = Y4;

YM5.OE = Y5;

YM6.OE = Y6;

YM7.OE = Y7;

XSD.COM = 0;

XSD.OE = !(XS # X7); "clamp the delay cap when all 'x' lines are 0

YGG.COM =!(YG & !XSD); "Enable the 3251 so long as both Yg is high AND xsd is low

"As soon as xsd goes high, disable the 3251

www.qprox.com

QT60xx5 / R1.05

7 Electrical Specifications

7.1 Absolute Maximum Specifications

Operating temp.................................................................. as designated by suffix

Storage temp......................................................................... -55

C to +125

..................................................................................... -0.5 to +5.5V

Max continuous pin current, any control or drive pin.................................................±10mA

Short circuit duration to ground, any pin............................................................infinite

Short circuit duration to V

, any pin.............................................................. infinite

Voltage forced onto any pin..................................................... -0.6V to (Vdd + 0.6) Volts

Frequency of operation......................................................................... 10MHz

Eeprom maximum writes............................................................ 100,000 write cycles

Flash maximum writes (eeprom backup).................................................1,000 write cycles

7.2 Recommended operating conditions

................................................................................... +4.75 to 5.25V

Supply ripple+noise.......................................................................5mV p-p max

Cx transverse load capacitance per key from X to Y.............................................. 0 to 20pF

Fosc oscillator frequency................................................................... 6MHz +/-2%

7.3 DC Specifications

Vdd = 5.0V, Cs = 15nF, Freq = 6.00MHz, Ta = recommended range, unless otherwise noted

Drdy, SS’ pinskohms12035Pullup resistorsR

bits8Acquisition resolutionA

µA±1Input leakage currentI

1mA sourceVVdd-0.7High output voltageV

4mA sinkV0.6Low output voltageV

V2.2High input logic levelV

V0.8Low input logic levelV

Brown-out detection voltageV

BOD

Not including external componentsµA20Supply current, sleepI

DDS

Not including external componentsmA15Supply current, runningI

DDR

Notes

UnitsMaxTypMinDescription

Paramete

7.4 Timing

From R2R setup to AIN+ sampleµS

8.16

ADC delay from R2R setup

Trad

1.5

SPI Clock rate

Fck

µS

Host command space

Tcm

µS2,00015Multi-byte return spacingT

µS1,0001Tdr delay from responseT

Notes

UnitsMaxTypMinDescription

Parameter

www.qprox.com

QT60xx5 / R1.05

7.5 Maximum Drdy Response Delays

... with adjacent key suppression disabled:

1ms1ms1.5ms1.2ms900us800us

All other commands

2ms2ms3.5ms2.8ms2.1ms1.8msGet key errors (E), Get keys pushed

4ms4ms9.5ms7.6ms5.7ms4.8ms

Calibrate command (all keys)

800ms800ms800ms800ms800ms800ms

Lock reference Level (L)

300ms300ms300ms300ms300ms300ms

Setup - put (affect 64 keys)

40ms40ms40ms40ms40ms40ms

Setup - put (affect 8 keys)

10ms10ms10ms10ms10ms10ms

Setup - put (affect 1 key)

2ms1ms500µs400µs300µs250µsFunction Type

Burst Spacing

... with adjacent key suppression enabled:

2ms2ms3.5ms2.4ms1.8ms1.5ms

All other commands

2ms2ms5ms4ms3ms2.5msGet key errors (E), Get keys pushed

4ms5ms11ms8.8ms6.6ms5.5ms

Calibrate command (all keys)

800ms800ms800ms800ms800ms800ms

Lock reference Level (L)

300ms300ms300ms300ms300ms300ms

Setup - put (affect 64 keys)

40ms40ms40ms40ms40ms40ms

Setup - put (affect 8 keys)

10ms10ms10ms10ms10ms10ms

Setup - put (affect 1 key)

2ms1ms500µs400µs300µs250µsFunction Type

Burst Spacing

Preliminary Data: All specifications subject to change

www.qprox.com

QT60xx5 / R1.05

8 Mechanical

8.1 Dimensions

8.2 Marking

www.qprox.com

QT60xx5 / R1.05

12 14 16 18 2220

15 17 19 2113

44 42 40 38 36 34

43 41 3739 35

SYMBOL

Millimeters Inches

Min Max Notes Min Max Notes

12.2111.75 0.458 0.478

0.09 0.20 0.003 0.008

0.45

0.05

0.75

0.15

1.20

0.018

0.002

0.030

0.006

0.047

0.80

0.30

BSC

8.00

0.80

0.45

0.031

0.012

BSC

0.315

0.031

0.018

9.90 10.10 0.386 0.394

o07 07

BSC BSC

SQSQ

Package Type: 44 Pin TQFP

8.00 0.315

QT60645-ASQT60645-AS-40

C to +105

QT60485-ASQT60485-AS-40

C to +105

QT60325-ASQT60325-AS-40

C to +105

QT60645-SQT60645-S0

C to +70

QT60485-SQT60485-S0

C to +70

QT60325-SQT60325-S0

C to +70

MarkingTQFPT

adc

subranging, 4, 5

adjacent key suppression, 8, 27

alert output, 15

application assistance, 5

block diagram, 5

boundary equation, 30, 33

burst length, 8, 9, 12, 20, 24, 25, 28, 34

burst spacing, 6, 25, 34

burst timing, 9, 19

calibration, 8, 13, 14, 15, 20, 21, 28

charge cancellation, 4, 9, 22

charge gate, 9

charge integrator, 4, 5, 9, 12, 13, 29

charge neutralization, 9

circuit model, 4, 5

cs, 6, 9, 13, 15, 29

cs clamp polarity, 29

csr drive polarity, 15

cx, 4, 6, 8, 9, 21, 25

cz, 5, 6, 7, 8, 9, 13, 14, 21, 28

dac test, 28

delta signals, 22

detect integrator, 22, 26

detection integrator, 6, 7, 22

device status, 22

device variations, 5

dimensions, 38

direction commands, 20

drdy’, 17, 18

drift compensation, 6, 7, 8, 13, 15, 20, 23, 24, 26

dwell, 34

gate dwell, 5, 9, 12, 13, 14, 16, 25

echo, 18, 19, 24, 28

eeprom checksum, 22, 28

electrostatic shield, 15

emi, 4, 27

error code, 23

Error byte, 23

error guardbanding, 7

esd protection, 16

fast-recalibration, 7, 8

field flow, 4

function summary table, 31

gate dwell

dwell, 5, 9, 12, 13, 14, 16, 25

get command, 20

ground plane, 15

hard reset, 8

hysteresis, 6, 25, 26, 32

intra-burst pulse spacing, 12, 27, 34

jfet, 13

key design, 5

key numbering convention, 21

key reporting, 23, 24

ladder dac

R2R ladder, 5, 7, 9, 14

led, 15

lock reference levels, 7, 17, 28

marking, 38

master mode, 16, 18, 19

master-slave mode, 16, 18

matrix configuration, 5

mechanical, 38

miso, 17, 18

mosi, 14, 17, 18, 19

multi-byte responses, 18, 19

negative detect integrator, 26

negative detect threshold, 12, 24

negative error band, 27

negative recalibration delay, 6, 26

negative threshold, 5, 6, 8, 12, 25, 26

noise, 12, 15, 16, 24, 26

noise coupling, 12

offset, 5, 6, 7, 8, 9, 13, 14, 21, 22, 28

opamp, 13

oscillator, 14, 16

oscilloscope sync, 15

pcb layout, 15

peel22cv10az, 13, 35

pld, 9, 12, 13, 14, 16, 35

positive detect threshold, 24

positive drift compensation, 26

positive error band, 27

positive recal delay, 7, 8

positive recalibration delay, 7, 26

positive threshold, 6, 7, 8, 25, 26

power supply, 15

put command, 20

qmbtn, 4, 15, 16

www.qprox.com

QT60xx5 / R1.05

9 Index

qs3251, 12, 13, 16, 35

qt60325, 9, 29

qt60485, 9, 29

r2r ladder

ladder DAC, 5, 7, 9, 14

recalibrate keys (command), 28

recalibration, 6, 7, 8, 13, 23, 24, 26, 28, 30

reference level, 4, 6, 7, 8, 25, 26, 27

reference levels, 22

reference window boundary, 8

reset, 4, 7, 8, 9, 13, 14, 15, 20, 21, 28, 29, 30, 35

resonator, 14, 15

response delays, 17, 37

return last command, 28

return part signature, 29

return part version, 29

rf emissions, 5

scan sequence

Matrix scan sequence, 9

sck, 17, 18, 19

scope, 16, 20, 21

scope commands, 21

sensitivity, 12

serial interface, 16

setup commands, 20, 24

signal gain, 9, 13, 25

signal levels, 4, 22

signal processing, 4, 5

slave mode, 16, 17, 18, 19

sleep mode, 14, 29

sleep_wake, 14, 15

soft reset, 8

spi, 4, 15, 16, 17, 18, 19, 20, 29

spi interface, 4

spi noise problems, 16

spi rate, 29

ss’, 17, 18, 19

startup, 13, 14, 15

status commands, 20, 21

subranging

ADC, 4, 5

supervisory functions, 20, 28

sync, 14, 15, 16, 18, 22, 29, 30

threshold level, 6, 7, 25, 26

timing limitations, 34

tlc2272, 13

uart, 16

vdd, 15, 16

vee, 15

virtual ground, 4

water films, 4, 14, 27

x electrode drives, 9

x2ws, 14

y gate drives, 12

yc0..yc7, 12

ys0..ys2, 12

www.qprox.com

QT60xx5 / R1.05

Notes -

QT60xx5 / R1.05

Patented and patents pending

Corporate Headquarters

1 Mitchell Point

Ensign Way, Hamble SO31 4RF

Great Britain

Tel: +44 (0)23 8056 5600 Fax: +44 (0)23 8045 3939

admin@qprox.com

www.qprox.com

North America

651 Holiday Drive Bldg. 5 / 300

Pittsburgh, PA 15220 USA

Tel: 412-391-7367 Fax: 412-291-1015

All specifications subject to change.

This device expressly not for use in any medical or human safety related

application without the express written consent of an officer of the company.