General Description
The RE46C120 is a low power CMOS ionization type smoke detector IC. With a 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.

FEATUREs
• Guard Outputs for Ion Detector Input
• +/-0.75pA Detect Input Current
• Internal Reverse Battery Protection
• Internal Low Battery Detection
• Pin Selectable Horn Pattern
• Low Quiescent Current Consumption (<6.5uA)
• 16L PDIP
• ESD Protection on all Pins
• Compatible with MC145017, MC14467
• Available in RoHS Compliant Pb Free Packaging