RE46C152E16F [Microchip]

The RE46C152 is a low power CMOS ionization type smoke detector IC. With few external components this circuit will provide all the required features for an ionization type smoke detector. An internal oscillator strobes power to the smoke detection circuitry for 10.5mS every 1.66 seconds to keep standby current to a minimum. A check for a low battery condition is performed every 40 seconds when in standby. The Tone input allows for selection of a temporal pattern or a 2/3 duty cycle continuous tone. The temporal horn pattern supports the NFPA 72 emergency evacuation signal. An interconnect pin allows multiple detectors to be connected such that when one units alarms all units will sound. An internal 8 minute timer allows for a separate button to be used for reduced sensitivity mode. Single button operation for test and timer mode is also possible. Although this device was designed for smoke detection utilizing an ionization chamber it could be used in a variety of security applications.