The ISL29028 is an integrated ambient and infrared

light-to-digital converter with a built-in IR LED driver

and I2C Interface (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 ISL29028 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 ISL29028 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 ISL29028 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.

特性 Features

? Works Under All Light Sources Including Sunlight

? Dual ADCs Measure ALS/Prox Concurrently

? Intelligent Interrupt Scheme Simplifies μC Code

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

? IR LED Driver with I2C Programmable Sink Currents

- 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

? I2C (SMBus Compatible) Output

? Temperature Compensated

? Tiny ODFN8 2.0x2.1x0.7 (mm) Package

Additional Features

? 1.7V to 3.63V Supply for I2C Interface

? 2.25V to 3.63V Sensor Power Supply

? Pb-Free (RoHS compliant)

? I2C Address Selection Pin

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