1

Low Power Ambient Light and Proximity Sensor with

Internal IR-LED and Digital Output

ISL29043

The ISL29043 is an integrated ambient and infrared

(SMBus Compatible). This device uses two independent ADCs

for concurrently measuring ambient light and proximity in

parallel. The flexible interrupt scheme is designed for minimal

microcontroller utilization.

For ambient light sensor (ALS) data conversions, an ADC

converts photodiode current (with a light sensitivity range up to

2000 Lux) in 100ms per sample. The ADC rejects 50Hz/60Hz

flicker noise caused by artificial light sources.

For proximity sensor (Prox) data conversions, the built-in driver

turns on an internal infrared LED and the proximity sensor ADC

converts the reflected IR intensity to digital. This ADC rejects

ambient IR noise (such as sunlight) and has a 540μs

conversion time.

The ISL29043 provides low power operation of ALS and

proximity sensing with a typical 136μA normal operation

current (110μA for sensors and internal circuitry, ~28μA for

LED) with 220mA current pulses for a net 100μs, repeating

every 800ms (or under).

The ISL29043 uses both a hardware pin and software bits to

indicate an interrupt event has occurred. An ALS interrupt is

defined as a measurement that is outside a set window. A

proximity interrupt is defined as a measurement over a

threshold limit. The user may also require that both ALS/Prox

interrupts occur at once, up to 16 times in a row before

activating the interrupt pin.

The ISL29043 is designed to operate from 2.25V to 3.63V over

the -40°C to +85°C ambient temperature range. It is packaged in

a clear, lead-free 10 Ld ODFN package.

Features

• Internal LED + Sensor = Complete Solution

• Works Under All Light Sources Including Sunlight

• Dual ADCs Measure ALS/Prox Concurrently

•<1.0μA Supply Current When Powered Down

• Temperature Compensated

• Pb-Free (RoHS compliant)

Intelligent and Flexible Interrupts

• Independent ALS/Prox Interrupt Thresholds

• Adjustable Interrupt Persistency

- 1/4/8/16 Consecutive Triggers Required Before Interrupt

Applications

• Display and Keypad Dimming Adjustment and Proximity

Sensing for:

- Mobile Devices: Smart Phone, PDA, GPS

- Computing Devices: Laptop PC, Netbook, Tablet PC

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

Camera

- Industrial and Medical Light and Proximity Sensing

Related Literature

• See AN1436, “Proximity Sensors”

FIGURE 1. TYPICAL APPLICATION DIAGRAM

FIGURE 2. PROXIMITY RESPONSE vs DISTANCE

ADDR0

2

GND

4

REXT

5

SDA

INT

8

IRDR 9

ISL29043

R1

10kΩ

R2

10kΩ

499kΩ

µCONTROLLER

INT

SDA

SLAVE_0

SLAVE_1

SCL

SDA

SCL

SDA

7

R3

10kΩ

SCL

6

C3

0.1µF

SCL

C2

1µF

10

1 LED+ LED-

C1

1.0µF

0

51

102

153

204

255

0

25

50

75

100

125

150

DISTANCE (mm)

220mA (18% GREY CARD)

110mA (18% GREY CARD)

110mA (WHITE COPY PAPER)

220mA (WHITE COPY PAPER)

February 9, 2012

FN7935.0

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 trademark owned by Intersil Corporation or one of its subsidiaries.

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