The RE46C168 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 µs every 10 seconds to keep standby current to a minimum. If smoke is sensed, the detection rate is increased to verify an alarm condition.A high gain mode is available for push button chamber testing.A check for a low battery condition and chamber integrity is performed every 43 seconds when in standby. A continuous tone horn pattern is used for the alarm condition.An interconnect pin allows multiple detectors to be connected so when one unit alarms, all units will sound.A charge dump feature will quickly discharge the interconnect line when exiting a local alarm.An internal 1.2 minute timer allows for single button, push-to-test to be used for a reduced sensitivity mode.An alarm memory feature allows the user to determine if the unit has previously entered a local alarm condition.Utilizing low-power CMOS technology, the RE46C168 was designed for use in smoke detectors that comply with Underwriters Laboratory Specification UL217 and UL268.

   Continuous Tone Pattern

   Alarm Memory

   Sensitivity Control Times: 1.2 minutes

   I/O Filter and Charge Dump

   Interconnect up to 40 Detectors

   Internal Power-on Reset

   >2000V ESD Protection (HBM) on All Pins

   Low Quiescent Current Consumption (

   Internal Low Battery Detection and Chamber Test

   RoHS Compliant Lead-Free Packaging