Photoelectric Smoke Detector AFE IC

The RAA239101 is a low-power Analog Front-End (AFE) IC; combined with a microcontroller, photoelectric emitter/detector(s), horn, and minimal external components, it forms a complete smoke detector.

The IC operates from a 3V to 5V or 9V battery and has an LDO to provide power to a microcontroller. The battery-check feature can be used to signal an alarm when the battery is low.

The RAA239101 provides a driver that can switch between two LEDs to pulse the smoke detection LED emitters with a DAC adjustable current. Two photodiode receiver channels with programmable gain amplification using an ADC allow the detection of smoke by sensing the LED light scattered off of smoke in a detection chamber.