Features

• 6-12V Operation

• Low Quiescent Current Consumption

• Programmable Standby Sensitivity

• Programmable HUSH Sensitivity

• Programmable Hysteresis

• Programmable Chamber Voltage for Push-to-Test

(PTT) and Chamber Test

• Programmable ±150 mV Low-Battery Set Point

• Internal Ionization Chamber Test

• Programmable Low Battery Test Duration

• Internal Power-on Reset (POR) and Power-Up

Low Battery Test

• Alarm Memory

• IO Filter and Charge Dump

• Interconnect Up to 40 Detectors

• ±5% All Internal Oscillator

• 9-Minute Timer for Sensitivity Control

• Temporal Horn Pattern

• Guard Outputs for Ion Detector Input

• ±0.75 pA Detect Input Current

• 10-year End of Life Indication

• Chamber Monitor Warning

Description

The RE46C181 is a next generation 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 10s 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 mode. 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 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.