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 3.3V 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.
- Ultra-low current consumption
- 9V or 3.3V battery operation
- LDO for microcontroller supply
- 10-bit ADC for measuring voltage on 7 analog pins
- Drives two LED emitters with 8-bit current DAC control from 45mA to 600mA
- Two photodiode receivers with programmable gain amplifiers
- General purpose IO
- Horn driver with clamp diodes
- SPI interface
- Photoelectric smoke detectors