MICROCHIP RE46C191S16F

The RE46C191 is a low-power, low-voltage CMOS photoelectric-type smoke detector IC. With minimal external components, this circuit provides all the required features for a photoelectric-type smoke detector. The design incorporates a gain-selectable photo amplifier for use with an infrared emitter/detector pair. To keep the standby current to a minimum, an internal oscillator strobes power to the smoke detection circuitry every 10 seconds. 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 is performed every 86 seconds and the chamber integrity is tested once every 43 seconds when in Standby mode. The temporal horn pattern supports the NFPA 72 emergency evacuation signal. An interconnect pin allows multiple detectors to be connected, such that when one unit alarms, all units will sound. An internal nine-minute timer can be used for a Reduced Sensitivity mode. Utilizing low-power CMOS technology, the RE46C191 is designed for use in smoke detectors that comply with Underwriters Laboratory Specification UL217.

• Two AA Battery Operation
• Low Quiescent Current Consumption
• Local Alarm Memory
• Interconnect Up to 40 Detectors
• Nine-Minute Timer for Sensitivity Control
• Temporal or Continuous Horn Pattern
• Internal Low Battery and Chamber Test
• All Internal Oscillator
• Internal Infrared Emitter Diode (IRED) Driver
• Adjustable IRED Drive Current
• Adjustable Hush Sensitivity
• Two Percent Low Battery Set Point
• Pin-for-Pin Compatible with RE46C190