The RE46C194 is a lowpower, low voltage CMOS photoelectric type smoke detector ASIC. With minimalexternal components, this circuit will provide all the required functions and features for aphotoelectric smoke detector. Programmablesetup, calibration and feature selection are the key to reduced component countand reduced manufacturing costs. The low averageoperating current of the RE46C194 allows smoke detectors to achieve 10-yearoperation with lithium ion batteries. Theboost regulator insures proper operation of the infrared diode and the piezoelectrichorn under low battery conditions. The design incorporatesa programmable gain integrating photo amplifier for use with an infrared emitterdiode. The infrared emitter drivecurrent is programmable along with smoke alarm limits which provides thedesigner with exceptional flexibility when designing a smoke detector. Smart IO with CO temporal horn pattern allows the RE46C194 to be used in combined CO and photoelectric smoke detectors.