The RE46C166 device is a low-power, CMOS photoelectric type, smoke detector IC. With minimal external components, this circuit will provide all the required features for a photoelectric type smoke detector. Each design incorporates a gain selectable photo amplifier for use with an infrared emitter/detector pair. An internal oscillator strobes power to the smoke detection circuitry for 100 ?s every 10 seconds to keep standby current to a minimum. If smoke is sensed, the detection rate is increased to veri