The RE46C180 is a low power, 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 5 ms every 10 seconds to keep the standby current to a minimum. A check for a Low Battery condition is performed every 80s and an ionization chamber test is performed once every 320s when in Standby. The temporal horn pattern complies with the National Fire Protection Association NFPA 72 ® National Fire Alarm and Signaling Code® for emergency evacuation signals. An interconnect pin allows multiple detectors to be connected, such that when one unit alarms, all units will sound. A charge dump feature quickly discharges the interconnect line when exiting a Local Alarm condition. The interconnect input is also digitally filtered. An internal 9 minute or 80s timer can be used for a Reduced Sensitivity mode. An alarm memory feature allows the user to determine whether the unit has previously entered a Local Alarm condition. Utilizing low-power CMOS technology, the RE46C180 is designed for use in smoke detectors that comply with the Standard for Single and Multiple Station Smoke Alarms, UL217 and the Standard for Smoke Detectors for Fire Alarm Systems, UL268.