ISL29015IROZ-T7 - Intersil Corporation

FN6522.0

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 1-888-468-3774 |Intersil (and design) is a registered trademark of Intersil Americas Inc.

All other trademarks mentioned are the property of their respective owners.

ISL29015

Integrated Digital Ambient Light Sensor

and Proximity Sensor

The ISL29015 is an integrated ambient and infrared light to

digital converter with a built-in IR LED driver and I2C/SMBus

interface. This device provides not only ambient light sensing

to allow robust backlight/display brightness control but also

infrared sensing to allow proximity estimation.

For ambient light sensing, an internal 16-bit ADC has been

designed based on the charge-balancing A/D conversion

technique. The ADC conversion time is nominally 100ms

and is user adjustable from 25µs to 100ms depends on

oscillator frequency and ADC resolution. This ADC is

capable of rejecting 50Hz and 60Hz flicker noise caused by

artificial light sources. The lux-range-select feature allows

users to program the lux range for optimized counts/lux.

For proximity sensing, the ADC is used to digitize the output

signal from the photodiode array when the internal IR LED

driver is turned on and off for the programmed time periods

under user-selected modulation frequency to drive the

external IR LED. As this proximity sensor employs a noise

cancellation scheme to highly reject unwanted IR noise, the

digital output of proximity sensing decreases with distance.

The driver output current is user selectable up to 100mA to

drive different types of IR emitters LEDs.

Six different modes of operation can be selected via the I2C

interface: Programmable ALS once with auto power-down,

programmable IR sensing once, programmable proximity

sensing once, programmable continuous ALS sensing,

programmable continuous IR sensing and programmable

continuous proximity sensing. The programmable one-time

operation modes greatly reduce power because an

immediate automatic shutdown reduces overall supply

current less than 1µA.

Designed to operate on supplies from 2.25V to 3.3V, the

ISL29015 is specified for operation over the -40°C to +85°C

ambient temperature range. It is packaged in a clear, Pb-free

6 Ld ODFN package.

Pinout ISL29015

(6 LD ODFN)

TOP VIEW

Features

Proximity Sensing

• Ambient IR Cancellation During Proximity Sensing

- Works Under Direct Sunlight

• IR LED Driver with Programmable Source Current

- Adjustable Current Drive from 100mA to 12.5mA

• Programmable LED current Modulation Frequency

• Variable Conversion Resolution up to 16-bits

Ambient Light S ensing

• Simple Output Code Directly Proportional to lux

• Adjustable Sensitivity up to 65 Counts per lux

• Selectable Range (via I2C)

- Range 1 = 0.015 lux to 1,000 lux

- Range 2 = 0.06 lux to 4,000 lux

- Range 3 = 0.24 lux to 16,000 lux

- Range 4 = 0.96 lux to 64,000 lux

• Integrated 50/60Hz Noise Rejection

• Works Under Various Light Sources, Including Sunlight

Ideal Spectral Response for Light and Proximity Sensor

• Light Sensor Close to Human Eye Response

- Excellent Light Sensor IR and UV Rejection

• Proximity sensor range from 850nm to 950nm

- Can use either 850nm or 950nm LED solution

Ultra Low Power

•90μA Max Operating Current

-1.0μA Max Shutdown Current

• Software Shutdown and Automatic Shutdown

Easy to Use

•I

2C (SMBus Compatible) Output

• No Complex Algorithms Needed

• Temperature Compensated

• Small Form Factor

- 2.0x2.1x0.7mm 6 Ld ODFN Package

Additional Fea tures

•I

2C and SMBus Compatible

• 1.7V to 3.63V Supply for I2C Interface

• 2.25V to 3.3V Supply

• Pb-Free (RoHS compliant)

Applications

• Display and Keypad Dimming Adjustment and Proximity

Sensing for:

- Mobile Devices: Smart Phone, PDA, GPS

- Computing Devices: Notebook PC, Webpad

- Consumer Devices: LCD-TV, Digital Picture Frame, Digital

Camera

• Industrial and Medical Light and Proximity Sensing

VDD

GND

REXT

IRDR

SDA

SCL

*EXPOSED PAD CAN BE CONNECTED TO GND OR

ELECTRICALLY ISOLATED

Data Sheet October 31, 2008

2FN6522.0

October 31, 2008

Block Diagram

Ordering Information

PART NUMBER

(Note) TEMP. RANGE

(°C) PACKAGE

(Pb-Free) PKG.

DWG. #

ISL29015IROZ-T7* -40 to +85 6 Ld ODFN L6.2x2.1

ISL29015IROZ-EVALZ Evaluation Board

*Please refer to TB347 for details on reel specifications.

NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and

NiPdAu plate - e4 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free

products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.

Pin Descriptions

PIN NUMBER PIN NAME DESCRIPTION

1 VDD Positive supply: 2.25V to 3.3V.

2 GND Ground pin.

3 REXT External resistor pin setting the internal reference current and the conversion time. 499kΩ with 1%

tolerance resistor is recommended.

4SCLI

2C serial clock line The I2C bus lines can be pulled from 1.7V to above VDD, 3.63V max.

5SDAI

2C serial data line

6 IRDR IR LED driver pin connecting to the anode of the external IR LED. The source current of the IR LED driver

can be programmed through I2C.

Exposed pad connected to ground or electrically isolated.

VDD

REXT GND

SDA

SCL

COMMAND

DATA

I2C

IR PHOTODIODE

LIGHT DATA

FOSC IRDR

IR DRIVER

ISL29015

ARRAY

PHOTODIODE

PROCESS

ALS AND IR

ARRAY

INTEGRATION

ADC

IREF

ISL29015

3FN6522.0

October 31, 2008

Absolute Maximum Ratings (TA = +25°C) Thermal Information

VDD Supply Voltage between VDD and GND . . . . . . . . . . . . . 3.6V

I2C Bus (SCL, SDA) Pin Voltage . . . . . . . . . . . . . . . . . . -0.2V to 4V

I2C Bus (SCL, SDA) Pin Current . . . . . . . . . . . . . . . . . . . . . <10mA

IRDR Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . -0.2V to VDD + 0.5V

REXT Pin Voltage. . . . . . . . . . . . . . . . . . . . . . . . -0.2V to VDD + 0.5V

ESD Rating

Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV

Thermal Resistance (Typical, Note 1) θJA (°C/W)

6 Ld ODFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Maximum Die Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . +90°C

Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +100°C

Operating Temperature . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C

Pb-Free Reflow Profile. . . . . . . . . . . . . . . . . . . . . . . . .see link below

http://www.intersil.com/pbfree/Pb-FreeReflow.asp

CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and

result in failures not covered by warranty.

NOTE:

1. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See

Tech Brief TB379.

IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests

are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA

Electrical Specifications VDD = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless

otherwise specified.

PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT

VDD Power Supply Range 2.25 3.3 V

IDD Supply Current when Powered Down Software disabled or auto power-down 0.1 1 µA

IDD1 Supply Current of Ambient Light and

IR Sensing

70 90 µA

VI2CSupply Voltage Range for I2C

Interface

1.7 3.63 V

fOSC Internal Oscillator Frequency 650 725 800 kHz

tint ADC Integration/Conversion Time 16-bit ADC data 90 ms

FI2CI2C Clock Rate Range 1 to 400 kHz

DATA_0 Count Output When Dark E = 0 lux 1 5 Counts

DATA_FS Full Scale ADC Code 65535 Counts

ΔDATA

DATA

Count Output Variation Over Three

Light Sources: Fluorescent,

Incandescent and Sunlight

Ambient light sensing ±10 %

DATA_1 Light Count Output With LSB of

0.015 lux/count

E = 300 lux, Fluorescent light (Note 2), Ambient light

sensing, Range 1 (1k lux)

15000 20000 25000 Counts

DATA_2 Light Count Output With LSB of

0.06 lux/count

E = 300 lux, Fluorescent light (Note 2), Ambient light

sensing, Range 2 (4k lux)

5000 Counts

DATA_3 Light Count Output With LSB of

0.024 lux/count

E = 300 lux, Fluorescent light (Note 2), Ambient light

sensing, Range 3 (16k lux)

1250 Counts

DATA_4 Light Count Output With LSB of

0.96 lux/count

E = 300 lux, Fluorescent light (Note 2), Ambient light

sensing, Range 4 (64k lux)

312 Counts

DATA_IR1 Infrared Count Output E = 210 lux, Sunlight (Note 3), IR sensing, Range 1 15000 20000 25000 Counts

DATA_IR2 Infrared Count Output E = 210 lux, Sunlight (Note 3), IR sensing, Range 2 5000 Counts

DATA_IR3 Infrared Count Output E = 210 lux, Sunlight (Note 3), IR sensing, Range 3 1250 Counts

DATA_IR4 Infrared Count Output E = 210 lux, Sunlight (Note 3), IR sensing, Range 4 312 Counts

VREF Voltage of REXT Pin 0.52 V

VIL SCL and SDA Input Low Voltage 0.6 V

VIH SCL and SDA Input High Voltage 1.5 V

ISL29015

4FN6522.0

October 31, 2008

Principles of Operation

Photodiodes and ADC

The ISL29015 contains two photodiode arrays which convert

light into current. The spectral response for ambient light

sensing and IR sensing is shown in Figure 6 in the performance

curves section. After light is converted to current during the light

signal process, the current output is converted to digital by a

built-in 16-bit Analog-to-Digital Converter (ADC). An I2C

command reads the ambient light or IR intensity in counts.

The converter is a charge-balancing integrating type 16-bit

ADC. The chosen method for conversion is best for converting

small current signals in the presence of an AC periodic noise. A

100ms integration time, for instance, highly rejects 50Hz and

60Hz power line noise simultaneously.

The built-in ADC offers user flexibility in integration time or

conversion time. There are two timing modes: Internal Timing

Mode and External Timing Mode. In Internal Timing Mode,

integration time is determined by an internal oscillator (fOSC),

and the n-bit (n = 4, 8, 12,16) counter inside the ADC. In

External Timing Mode, integration time is determined by the

time between two consecutive I2C External Timing Mode

commands. See “Integration and Conversion Time” on page 7.

A good balancing act of integration time and resolution

depending on the application is required for optimal results.

The ADC has I2C programmable range select to dynamically

accommodate various lighting conditions. For very dim

conditions, the ADC can be configured at its lowest range

(Range 1) in the ambient light sensing. For very bright

conditions, the ADC can be configured at its highest range

(Range 4) in the proximity sensing.

Low-Power Operation

The ISL29015 initial operation is at the power-down mode after

a supply voltage is provided. The data registers contain the

default value of 0. When the ISL29015 receives an I2C

command to do a one-time measurement from an I2C master, it

will start ADC conversion with light or proximity sensing. It will

go to the power-down mode automatically after one conversion

is finished and keep the conversion data available for the

master to fetch anytime afterwards. The ISL29015 will

continuously do ADC conversion with light or proximity sensing

if it receives an I2C command of continuous measurement. It

will continuously update the data registers with the latest

conversion data. It will go to the power-down mode after it

receives the I2C command of power-down.

Ambient Light, IR and Proximity Sensing

There are six operational modes in ISL29015: Programmable

ALS once with auto power-down, programmable IR sensing

once with auto power-down, programmable proximity sensing

once with auto power-down; programmable continuous ALS

sensing, programmable continuous IR sensing and

ISDA SDA Current Sinking Capability 4 5 mA

IIRDR1 IRDR Source Current IS<1:0> = 0 (Note 4)

1.5V at IRDR pin

100 mA

IIRDR2 IRDR Source Current IS<1:0> = 1 (Note 4) 44 50 56 mA

IIRDR3 IRDR Source Current IS<1:0> = 2 (Note 4) 25 mA

IIRDR4 IRDR Source Current IS<1:0> = 3 (Note 4) 12.5 mA

VIRLED Voltage Head Room of IRDR Pin VDD - 0.6 V

tr Rise Time for IRDR Source Current RLOAD = 15Ω at IRDR pin, 20% to 80% 35 ns

tf Fall Time for IRDR Source Current RLOAD = 15Ω at IRDR pin, 80% to 20% 10 ns

fIRLED1 IR LED Modulation Frequency Freq<1:0> = 0 (Note 4) DC kHz

fIRLED2 IR LED Modulation Frequency Freq<1:0> = 3 (Note 4) 360 kHz

IDD (IRLED1) Supply Current of Proximity Sensing IS<1:0> = 0, Freq<1:0> = 0 (Note 4) 101 mA

IDD (IRLED2) Supply Current of Proximity Sensing IS<1:0> = 0, Freq<1:0> = 3 (Note 4) 51 mA

Duty Cycle Duty Cycle of IR LED Modulation 50 %

PROX-IR

PROX

Differential ADC Output of IR and

Proximity Sensing With Object Far

Away to Provide No Reflection

IR and proximity sensing with Range 2; 1.5V @ IRDR

pin, IS<1:0> = 0, Freq<1:0> = 0; E = 210 lux, Sunlight.

2.0 %

NOTES:

2. 550nm green LED is used in production test. The 550nm LED irradiance is calibrated to produce the same DATA count against an illuminance

level of 300 lux fluorescent light.

3. 850nm infrared LED is used in production test. The 850nm LED irradiance is calibrated to produce the same DATA_IR count against an

illuminance level of 210 lux sunlight at sea level.

4. See “Register Set” on page 6.

Electrical Specifications VDD = 3V, TA = +25°C, REXT = 499kΩ 1% tolerance, 16-bit ADC operation, unless

otherwise specified. (Continued)

PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT

ISL29015

5FN6522.0

October 31, 2008

programmable continuous proximity sensing. These six modes

can be programmed in series to fulfill the application needs.

The detailed program configuration is listed in “Register Set” on

page 6.

When the part is programmed for ambient light sensing, the

ambient light with wavelength within the “Ambient Light

Sensing” spectral response curve in Figure 6 is converted

into current. With ADC, the current is converted to an

unsigned n-bit (up to 16 bits) digital output.

When the part is programmed for infrared (IR) sensing, the

IR light with wavelength within the “IR or Proximity Sensing”

spectral response curve on Figure 6 is converted into

current. With ADC, the current is converted to an unsigned

n-bit (up to 16 bits) digital output.

When the part is programmed for proximity sensing, the

external IR LED is turned on by the built-in IR LED driver

through the IRDR pin. The amplitude of the IR LED current

and the IR LED modulation frequency can be programmed

through Command Register II. When the IR from the LED

reaches an object and gets reflected back, the reflected IR

light with wavelength within the “IR or Proximity Sensing”

spectral response curve in Figure 6 is converted into current.

With ADC, the current is converted to an unsigned n-bit (up

to 16 bits) digital output. The output reading is inversely

proportional to the square of the distance between the

sensor and the object. When there is significant background

IR noise like direct sunlight, both IR and proximity sensing

can be implemented for background noise cancellation. The

differential output reading from the ADC decreases with

distance.

I2C Interface

There are four 8-bit registers available inside the ISL29015.

The two command registers define the operation of the device.

The command registers do not change until the registers are

overwritten. The two 8-bit data Read Only registers are for the

ADC output. The data registers contain the ADC's latest digital

output, or the number of clock cycles in the previous integration

period.

The ISL29015’s I2C interface slave address is internally

hardwired as 1000100. When 1000100x with x as R or W is

sent after the Start condition, this device compares the first

seven bits of this byte to its address and matches.

Figure 1 shows a sample one-byte read. Figure 2 shows a

sample one-byte write. The I2C bus master always drives

the SCL (clock) line, while either the master or the slave can

drive the SDA (data) line. Figure 2 shows a sample write.

Every I2C transaction begins with the master asserting a

start condition (SDA falling while SCL remains high). The

following byte is driven by the master, and includes the slave

address and read/write bit. The receiving device is

responsible for pulling SDA low during the

acknowledgement period. Every I2C transaction ends with

the master asserting a stop condition (SDA rising while SCL

remains high).

For more information about the I2C standard, please consult

the Philips™ I2C specification documents.

FIGURE 1. I2C READ TIMING DIAGRAM SAMPLE

START WA A

A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A A6 A5 A4 A3 A2 A1 A0 W A

A A AD7D6D5D4D3D2D1D0

1357 1357 123456 9 2 4 6

STOP START

SDA DRIVEN BY MASTER

DEVICE ADDRESS

SDA DRIVEN BY ISL29015

DATA BYTE0REGISTER ADDRESS

OUT

DEVICE ADDRESS

I2C DATA

SDA DRIVEN BY MASTER

2468

924689 78 1 3 5 789

I2C SDA

I2C CLK

ISL29015

6FN6522.0

October 31, 2008

There are four registers that are available in the ISL29015. Table 1 summarizes their functions.

Command Register I 00(hex)

The first command register has the following functions:

1. Operation Mode: Bits 7, 6, and 5.These three bits

determines the operation mode of the device.

2. Bit 4 to 0 has been reserved to 0.

Command Register II 01(hex)

The second command register has the following functions:

1. Amplitude of IR driver current: Bits 7 and 6. This device

provides current source to drive an external IR LED. The

drive capability can be programmed through Bits 7 and 6.

For example, the device sources 100mA out of the IRDR

pin if Bits 7 and 6 are 0 during proximity sensing.

2. Modulation Frequency: Bits 5 and 4. These two bits set

the IR LED driver’s modulation frequency.

3. Resolution: Bits 3 and 2. Bits 3 and 2 determine the

ADC’s resolution and the number of clock cycles per

conversion in Internal Timing Mode. Changing the

number of clock cycles does more than just change the

resolution of the device. It also changes the integration

time, which is the period the device’s analog-to-digital

FIGURE 2. I2C WRITE TIMING DIAGRAM SAMPLE

START W A A

A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A B7 B6 B5 B4 B3 B2 B1 B0 A

12615948

STOP

SDA DRIVEN BY MASTER

FUNCTIONSREGISTER ADDRESSDEVICE ADDRESS

SDA DRIVEN BY MASTER SDA DRIVEN BY MASTER

I2C DATA

I2C SDA IN

I2C SDA OUT

I2C CLK IN

345 789 234 678 123 567 9

TABLE 1. REGISTER SET

ADDR REG NAME

BIT

7 6 5 4 3 2 1 0 DEFAULT

00h COMMANDIOP2 OP1 OP0 0 0 0 0 0 00h

01h COMMANDII IS1 IS0 FREQ1 FREQ0 RES1 RES0 RANGE1 RANGE0 00h

02h DATALSB D7 D6 D5 D4 D3 D2 D1 D0 00h

03h DATAMSB D15 D14 D13 D12 D11 D10 D9 D8 00h

TABLE 2. OPERATION MODE

BITS 7 TO 5 OPERATION

000 Power-down the device

001 ALS once

010 IR once

011 Proximity once

100 Reserved

101 ALS continuous

110 IR continuous

111 Proximity continuous

TABLE 3. CURRENT SOURCE CAPABILITY AT IRDR PIN

BITS 7: 6 IRDR PIN SOURCE CURRENT

00 100mA IR LED driver

01 50mA IR LED driver

10 25mA IR LED driver

11 12.5mA IR LED driver

TABLE 4. MODULATION FREQUENCY

BITS 5:4 MODULATION FREQUENCY

(kHz)

00 DC

01 N/A

10 N/A

11 360

ISL29015

7FN6522.0

October 31, 2008

(A/D) converter samples the photodiode current signal for

a measurement.

4. Range: Bits 1 and 0. The Full Scale Range (FSR) can be

adjusted via I2C using Bits 1 and 0. Table 6 lists the

possible values of FSR for the 499kΩ REXT resistor.

Data Registers (02 hex and 03 hex)

The device has two 8-bit read-only registers to hold the data

from LSB to MSB for ADC. The most significant bit (MSB) is

accessed at 03 hex, and the least significant bit (LSB) is

accessed at 02 hex. For 16-bit resolution, the data is from

D0 to D15; for 12-bit resolution, the data is from D0 to D11;

for 8-bit resolution, the data is from D0 to D7. The registers

are refreshed after every conversion cycle.

Calculating Lux

The ISL29015’s ADC output codes, DATA, are directly

proportional to lux in the ambient light sensing.

Here, Ecal is the calculated lux reading. The constant α is

determined by the Full Scale Range and the ADC’s

maximum output counts. The constant is independent on the

light sources (fluorescent, incandescent and sunlight)

because of the light sources’ IR component is removed

during the light signal process. The constant can also be

viewed as the sensitivity: the smallest lux measurement the

device can measure is shown in Equation 2.

Here, Range(k) is defined in Table 6. Countmax is the

maximum output counts from the ADC.

The transfer function used for n-bit ADC becomes:

Here, n = 4, 8, 12 or 16. This is the number of ADC bits

programmed in the command register. 2n represents the

maximum number of counts possible from the ADC output.

Data is the ADC output stored in the data registers (02 hex

and 03 hex).

Integration and Conversion Time

The ADC resolution and fOSC determines the integration

time, tint.

where n is the number of bits of resolution and n = 4, 8, 12 or

16. 2n, therefore, is the number of clock cycles. n can be

programmed at the command register 01(hex) bits 3 and 2.

External Scaling Resistor REXT for fOSC and

Range

The ISL29015 uses an external resistor REXT to fix its

internal oscillator frequency, fOSC and the light sensing

range. fOSC and Range are inversely proportional to REXT

For user simplicity, the proportionality constant is referenced

to 499kΩ:

Noise Rejection

In general, integrating type ADC’s have excellent

noise-rejection characteristics for periodic noise sources whose

frequency is an integer multiple of the conversion rate. For

instance, a 60Hz AC unwanted signal’s sum from 0ms to

k*16.66ms (k = 1,2...ki) is zero. Similarly, setting the device’s

integration time to be an integer multiple of the periodic noise

signal, greatly improves the light sensor output signal in the

presence of noise.

ADC Output in IR Sensing

The ISL29015’s ADC output codes, DATA, are directly

proportional to the IR intensity received in the IR sensing

phase.

TABLE 5. RESOLUTION/WIDTH

BITS 3:2 NUMBER OF CLOCK CYCLES n-BIT ADC

00 216 = 65,536 16

01 212 = 4,096 12

10 28 = 256 8

11 24 = 16 4

TABLE 6. RANGE/FSR LUX

BITS

1:0 k RANGE(k) FSR (LUX) @

ALS SENSING FSR @ IR

SENSING

00 1 Range1 1,000 Refer to page 3

01 2 Range2 4,000 Refer to page 3

10 3 Range3 16,000 Refer to page 3

11 4 Range4 64,000 Refer to page 3

TABLE 7. DATA REGISTERS

ADDRESS

(hex) CONTENTS

02 D0 is LSB for 4, 8, 12 or 16-bit resolution, D3 is MSB

for 4-bit resolution, D7 is MSB for 8-bit resolution

03 D15 is MSB for 16-bit resolution, D11 is MSB for

12-bit resolution

Ecal αDATA×=(EQ. 1)

Range k()

Countmax

----------------------------

=(EQ. 2)

TABLE 8. INTEGRATION TIME OF n-BIT ADC

REXT

(kΩ) n = 16-BIT n = 12-BIT n = 8-BIT n = 4-BIT

250 45ms 2.812ms 175.5µs 10.8µs

499** 90ms 5.63ms 351µs 21.6µs

**Recommended REXT resistor value

(EQ. 3)

Ecal

Range k()

--------------------------- DATA×=

tint 2n1

fOSC

--------------

×2nREXT

725kHz 499kΩ×

----------------------------------------------

×== (EQ. 4)

(EQ. 5)

Range 499kΩ

REXT

------------------ Range k()×=

(EQ. 6)

fOSC

499kΩ

REXT

------------------ 725×kHz=

ISL29015

8FN6522.0

October 31, 2008

Here, EIR is the received IR intensity. The constant β

changes with the spectrum of background IR noise like

sunlight and incandescent light. The β also changes with the

ADC’s range and resolution selections.

ADC Output in Proximity Sensing

In the proximity sensing, the ADC output codes, DATA, are

directly proportional to the total IR intensity from the

background IR noise and from the IR LED driven by the

ISL29015.

β and EIR in Equation 8 have the same meanings as in

Equation 7. The constant γ depends on the spectrum of the

used IR LED and the ADC’s range and resolution selections.

ELED is the IR intensity which is emitted from the IR LED

and reflected by a specific objector to the ISL29015. ELED

depends on the current to the IR LED and the surface of the

object. ELED decreases with the square of the distance

between the object and the sensor.

If background IR noise is small, i.e., EIR can be neglected,

the ADC output directly decreases with the distance. If there

is significant background IR noise, the sequence of the

proximity sensing followed by the IR sensing can be

implemented. The differential reading of ADC outputs from

the proximity and IR sensing has no effect of background

IR noise and directly decreases with the distance between

the object and the sensor. Please refer to “Typical

Performance Curves” on page 10 for ADC output vs

distance. Figure 9 shows ISL29015 configured at 12-bit ADC

resolution, 12.5mA external LED current at 327.7KHz

modulation frequency, detects three different sensing

objects: 92% brightness paper, 18% gray card and ESD

black foam. Figure 10 shows ISL29015 configured at 12-bit

ADC resolution, programmed external LED at 327.7KHz

modulation frequency, detects the same sensing object: 18%

gray card under four different external LED current: 12.5mA,

25mA, 50mA and 100mA to compare the proximity readout

versus distance.

Current Consumption Estimation

The low power operation is achieved through sequential

readout in the serial fashion, as shown in Figure 3, the

device requires three different phases in serial during the

entire detection cycle to do ambient light sensing, infrared

sensing and proximity sensing. The external IR LED will only

be turned on during the proximity sensing phase under user

program controlled current at modulated frequency depends

on user selections. Figure 3 also shows the current

consumption during each ALS, IR sensing and Proximity

sensing phase. For example, at 8-bit ADC resolution the

integration time is 0.4ms. If user programed 50mA current to

supply external IR LED at 327.7kHz modulated frequency,

during the entire operation cycle that includes ALS, IR

sensing and Proximity sensing three different serial phases,

the detection occurs once every 30ms, the average current

consumption including external IR LED drive current can be

calculated from Equation 9:

If at a 12-bit ADC resolution where the integration time for

each serial phase becomes 7ms and the total detection time

becomes 100ms, the average current can be calculated from

Equation 10:

Suggested PCB Footprint

It is important that the users check the “Surface Mount

Assembly Guidelines for Optical Dual FlatPack No Lead

(ODFN) Package” before starting ODFN product board

mounting.

http://www.intersil.com/data/tb/tb477.pdf

Layout Considerations

The ISL29015 is relatively insensitive to layout. Like other

I2C devices, it is intended to provide excellent performance

even in significantly noisy environments. There are only a

few considerations that will ensure best performance.

Route the supply and I2C traces as far as possible from all

sources of noise. Use two power-supply decoupling

capacitors, 1µF and 0.1µF, placed close to the device.

Typical Circuit

A typical application for the ISL29015 is shown in Figure 4.

The ISL29015’s I2C address is internally hardwired as

1000100. The device can be tied onto a system’s I2C bus

together with other I2C compliant devices.

Soldering Considerations

Convection heating is recommended for reflow soldering;

direct-infrared heating is not recommended. The plastic

ODFN package does not require a custom reflow soldering

profile, and is qualified to +260°C. A standard reflow

soldering profile with a +260°C maximum is recommended.

DATAIR βEIR

×=(EQ. 7)

DATAPROX βEIR

×γELED

×+= (EQ. 8)

0.05mA 0.05mA 1mA (50mA∗50%))∗0.4ms+++()[]/30ms = 0.35mA

(EQ. 9)

0.05mA 0.05mA 1mA (50mA∗50%))∗7ms+++()[]/100ms = 1.83mA

(EQ. 10)

ISL29015

9FN6522.0

October 31, 2008

FIGURE 3. CURRENT CONSUMPTION FOR EACH INTEGRATION PHASE AND DETECTION CYCLE

ALS

PROXIMITY

IR LED

0.4ms

50µA

50mA

1mA

327.7 kHz

1µs 30ms

FIGURE 4. ISL29015 TYPICAL CIRCUIT

VDD

GND

REXT

3SCL

SDA 5

IRDR 6

ISL29015

10kΩR2

10kΩ

REXT

499kΩ

0.1µF

1µF

2.25V TO 3.3V

MICROCONTROLLER

SDA

SCL

I2C SLAVE_0 I2C SLAVE_1 I2C SLAVE_n

I2C MASTER

SCL

SDA

SCL

SDA

1.7V TO 3.63V

ISL29015

10 FN6522.0

October 31, 2008

Typical Performance Curves VDD = 3V, Rext = 499kΩ

FIGURE 5. SPECTRUM OF FOUR LIGHT SOURCES FIGURE 6. SPECTRAL RESPONSE FOR AMBIENT LIGHT

SENSING AND PROXIMITY SENSING

FIGURE 7. RADIATION PATTERN FIGURE 8. SENSITIVITY TO FOUR LIGHT SOURCES

FIGURE 9. ADC OUTPUT vs DIST ANCE WITH DIFFERENT

OBJECTS IN PROXIMITY SENSING FIGURE 10. ADC OUTPUT vs DIST ANCE WITH DIFFERENT

LED CURRENT AMPLITUDES IN PROXIMITY

SENSING

0.2

0.4

0.6

0.8

1.0

1.2

300 400 500 600 700 800 900 1000 1100

WAVELENGTH (nm)

NORMALIZED LIGHT INTENSITY

SUN INCANDESCENT

HALOGEN

FLUORESCENT

-0.2

0.2

0.4

0.6

0.8

1.2

300 400 500 600 700 800 900 1000 1100

WAVELENGTH (nm)

NORMALIZED RESPONSE

HUMAN EYE RESPONSE

AMBIENT

LIGHT

SENSING IR AND

PROXIMITY

SENSING

RADIATION PATTERN

LUMINOSITY

ANGLE

RELATIVE SENSITIVITY

90°

80°

70°

60°

50°

40°

30° 20° 10° 0° 10° 20° 30° 40°

50°

60°

70°

80°

90°

0.2 0.4 0.6 0.8 1.0 0

100

200

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000

LUX METER READING (LUX)

CALCULATED ALS READING (LUX)

INCANDESCENT

HALOGEN

FLUORESCENT

VDD = 3V

RANGE = 1000 LUX

16-BIT ADC

ADC OUTPUT (COUNT)

32768

65535

1000 LUX

Ecal = 216 x DATA

100

1000

10000

0 20406080100

DISTANCE (mm)

DATAPROX-DATAIR

92% BRIGHTNESS PAPER

18% GRAY CARD

ESD BLACK FOAM

500

1000

1500

2000

2500

3000

3500

4000

4500

0 102030405060708090

DISTANCE (mm)

DATAPROX-DATAIR (COUNT)

IIRLED = 100mA

IIRLED = 50mA

IIRLED = 25mA

IIRLED = 12.5mA

ISL29015

11 FN6522.0

October 31, 2008

FIGURE 11. OUTPUT CODE FOR 0 LUX vs TEMPERATURE FIGURE 12. OUTPUT CODE vs TEMPERATURE

FIGURE 13. OUTPUT CURRENT vs TEMPERA TURE IN

PROXIMITY SENSING FIGURE 14. SUPPLY CURRENT vs TEMPERATURE IN ALS

SENSING

Typical Performance Curves VDD = 3V, Rext = 499kΩ (Continued)

OUTPUT CODE (COUNTS)

TEMPERATURE (°C)

-60 -20 20 60 100

OUTPUT CODE RATIO (FROM +30°C)

TEMPERATURE (°C)

0.90

0.95

1.00

1.05

1.10

-60 -20 20 60 100

300 Lux FLUORESCENT LIGHT

ALS SENSING

100.0

100.5

101.0

101.5

102.0

102.5

103.0

103.5

104.0

104.5

105.0

-40-200 20406080100120

TEMPERATURE (°C)

IRDR OUTPUT CURRENT (mA)

PROXIMITY SENSING

IS<1:0> = 0

-40-200 20406080100120

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

ALS SENSING

10,000 Lux

ISL29015

All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.

Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality

Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without

notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and

reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result

from its use. No lice nse is gran t ed by i mpli catio n or other wise u nder an y p a tent or patent right s of Int ersi l or it s sub sidi aries.

For information regarding Intersil Corporation and its products, see www.intersil.com

FN6522.0

October 31, 2008

FIGURE 15. 6 LD ODFN SENSOR LOCATION OUTLINE

ISL29015

13 FN6522.0

October 31, 2008

ISL29015

Package Outline Drawing

L6.2x2.1

6 LEAD OPTICAL DUAL FLAT NO-LEAD PLASTIC PACKAGE (ODFN)

Rev 0, 9/06

located within the zone indicated. The pin #1 identifier may be

Unless otherwise specified, tolerance: Decimal ± 0.05

Tiebar shown (if present) is a non-functional feature.

The configuration of the pin #1 identifier is optional, but must be

between 0.15mm and 0.30mm from the terminal tip.

Dimension b applies to the metallized terminal and is measured

Dimensions in () for Reference Only.

Dimensioning and tolerancing conform to AMSE Y14.5m-1994.

either a mold or mark feature.

Dimensions are in millimeters.1.

NOTES:

(4X) 0.10

INDEX AREA

PIN 1

2.10

2.00

SEATING PLANE

BASE PLANE

0.08

0.10

SEE DETAIL "X"

0 . 00 MIN.

DETAIL "X"

0. 05 MAX.

0. 2 REF

SIDE VIEW

TYPICAL RECOMMENDED LAND PATTERN

(6X 0. 30)

(6X 0. 55)

TOP VIEW

(0. 65)

(1. 95)

(0. 65) (1. 35)

BOTTOM VIEW

6X 0. 35 ± 0. 05

B0.10 MAC

1. 35 1. 30 REF

INDEX AREA

PIN 1

0.65

0. 65

MAX 0.75

6X 0. 30 ± 0. 05