The ISL29147 is a low power Ambient Light Sensor (ALS) and

proximity (PROX) sensor. It has a built-in IR-LED for the

proximity function. The ALS function measures the amount of

light (in the visible spectrum) incident on the ISL29147.

The ALS function has a programmable ambient IR-rejection,

which allows fine tuning of light source variations and is ideal

for light sensor applications under dark protective glass. The

ALS provides a 12-bit measurement. A passive optical filter

removes unwanted wavelengths (IR or Ultraviolet) to ensure

accurate ALS measurement.

The proximity function includes a new offset adjustment to

compensate for the IR light reflected off the inside of the

protective glass cover and back to the ISL29147 sensor. This

offset adjustment allows the sensor to compensate for these

internal reflections and preserve the dynamic range of the

proximity measurement.

The built-in current-driver pulses an external infrared LED at a

programmed current for 90μs. The infrared light that is

reflected and received by the ISL29147 is digitized by an 8-bit

ADC. The proximity sensor also has a passive optical filter

designed to pass IR and reject visible wavelengths.

The ISL29147 provides a hardware pin to indicate an interrupt

event. The interrupt pin saves power as the host microcontroller

can ‘wake-up’ on an interrupt event and does not need to poll

the device for an interrupt event. The interrupt generator is

user configurable and provides several options for ALS and

PROX trigger configurations. The ISL29147 supports an SMBus

compatible I2C interface for configuration and control.

特性 Features

? Internal IR-LED and sensor for a complete solution

? Ideal for applications under dark or tinted glass

? Enhanced ambient sunlight rejection to 40k Lux

? Programmable proximity sleep time between proximity

measurements optimizes power consumption

? Hardware interrupt - no polling required

? Programmable IR compensation to fine-tune ALS

performance for various glass compositions

? Programmable IR LED drive current to 250mA

? Operates from 2.25V to 3.63V VDD

? Power-down IDD, typical 0.2μADC

? Tiny 2.40x4x1.2 (mm) optical co-package

Applications

? Display dimming and adjustment

- Mobile devices: smart phones, PDA, GPS

- Computing: monitors, laptops, notebooks

- Picture frames, tablet-PCs, LCD-TV

? Object detection

- Touchscreen disabling

- Smart power-saving