The RE46C181 is a next generation low power programmable CMOS ionization type smoke detector IC. With minimal external components this circuit will provide all the required features for an ionization type smoke detector. An on-chip oscillator strobes power to the smoke detection circuitry for 5ms every 10 seconds to keep standby current to a minimum. A check for a low battery condition is performed every 80 seconds and ionization chamber test is performed once every 320 seconds when in standby. 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. A charge dump feature will quickly discharge the interconnect line when exiting a local alarm. The interconnect input is also digitally filtered. An internal 9 minute timer can be used for a reduced sensitivity mode. A local alarm memory feature allows the user to determine if the unit has previously entered a local alarm condition.  A Chamber Monitor function checks for ionization chamber degradation. 

• 6 -12V Operation
• Low Quiescent Current Consumption
• +/- 0.75pA Detect Input Current
• Guard Outputs for Ion Detector Input
• Programmable Standby Sensitivity
• Programmable Hush Sensitivity
• Programmable Hysteresis
• Programmable Chamber Voltage for Push-to-Test
• Programmable Low Battery Set Point
• Local Alarm Memory
• 9 Minute Hush Timer
• Temporal Horn Pattern
• Interconnect up to 40 Detectors
• IO Filter and Charge Dump
• 10-Year End-of-Life Indication
• Chamber Monitor Warning