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Low Power Ambient Light and Proximity Sensor with

Intelligent Interrupt and Sleep Modes

ISL29028A

The ISL29028A is an integrated ambient and infrared light-to-

(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 external 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 ISL29028A provides low power operation of ALS and

proximity sensing with a typical 138μA normal operation current

(110μA for sensors and internal circuitry, ~28μA for external LED)

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

800ms (or under).

The ISL29028A uses both a hardware pin and software bits to

indicate an interrupt event has occurred. An ALS interrupt is

defined as a measurement which 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 ISL29028A 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 8 lead ODFN package.

Applications

• Display and Keypad Dimming Adjustment and Proximity

Sensing for:

- Mobile Devices: Smart Phone, PDA, GPS

- Computing Devices: Laptop PC, Netbook

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

Camera

• Industrial and Medical Light and Proximity Sensing

Features

• Works Under All Light Sources Including Sunlight

• Dual ADCs Measure ALS/Prox Concurrently

• Intelligent Interrupt Scheme Simplifies μC Code

•0.5% Typical Nonlinearity

Ambient Light Sensing

• Simple Output Code Directly Proportional to lux

• 50Hz/60Hz Flicker Noise and IR Rejection

• Light Sensor Close to Human Eye Response

• Selectable 125/2000 Lux Range

Proximity Sensing

• Proximity Sensor with Broad IR Spectrum

- Can Use 850nm and 950nm External IR LEDs

-Net 100μs Pulse with 110mA or 220mA Amplitudes

- Periodic Sleep Time up to 800ms Between Pulses

• Ambient IR Noise Cancellation (Including Sunlight)

Intelligent and Flexible Interrupts

• Independent ALS/Prox Interrupt Thresholds

• Adjustable Interrupt Persistency

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

Ultra Low Power

•138μA DC Typical Supply Current for ALS/Prox Sensing

-110μA for Sensors and Internal Circuitry

-28μA Typical Current for External IR LED (Assuming

220mA for 100μs Every 800ms)

•<1.0μA Supply Current When Powered Down

Easy to Use

• Set Registers; Wait for Interrupt

• Temperature Compensated

• Tiny ODFN8 2.0x2.1x0.7 (mm) Package

Additional Features

• 2.25V to 3.63V Sensor Power Supply

• Pb-Free (RoHS Compliant)

January 29, 2014

FN7721.3

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

1-888-INTERSIL or 1-888-468-3774

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