RAA239101 Datasheet | Renesas

Photoelectric Smoke Detector AFE IC The RAA239101 is a low-power Analog Front-End (AFE) IC; bined with a microcontroller, photoelectric emitter/detector(s), horn, and minimal external ponents, it forms a plete 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 IC provides an SPI bus for a microcontroller interface and a general-purpose IO. 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. Features - 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 45m A to 600m A - Two photodiode receivers with programmable gain amplifiers - General purpose IO - Horn driver with clamp diodes - SPI interface Applications - Photoelectric smoke detectors A piezoelectric horn driver is also included to provide CONFIDENTIAL an audible alarm. Battery Type VDD VDD VDD 3.3V or 9V Battery Jumper 3.3V 9V JP1 Short Open RESET JP2 Short Open TOOL0 Programmer RESET TOOL0 P146 P147 Visible LEDs VDD...