ISL29028A

The ISL29028A 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 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.