RE46C194 CMOS Low-Voltage Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Features Description 3V Lithium or Two AA Battery Operation The RE46C194 is a low-power, low-voltage CMOS photoelectric-type smoke detector IC. With minimal Low Quiescent Current Consumption external components, this circuit will provide all the Programmable IRED Drive Current required features for a photoelectric smoke detector. Programmable Photo Amp Setup The design incorporates a programmable gain photo 6-Bit ADC amplifier for use with an infrared emitter/detector pair. Programmable Alarm Limits An internal oscillator strobes power to the smoke Long-Term Drift Adjustment detection circuitry every ten seconds to keep the Chamber Test standby current to a minimum. If smoke is sensed, the 9-Minute Timer for Hush Operation detection rate is increased to verify an Alarm condition. Programmable Feature Selection A High-Gain mode is available for push button chamber testing. Low Battery Test Temporal or Continuous Horn Pattern A check for a low battery condition is performed every 86 seconds and chamber integrity is tested once every Horn Synchronization 43 seconds when in Standby mode. The temporal horn Auto-Alarm Locate pattern supports the NFPA 72 emergency evacuation Local Alarm Memory signal. Interconnect Up to 40 Detectors An interconnect pin allows multiple detectors to be Remote CO Alarm Response connected, such that when one unit alarms, all units will Compatible with the RE46C191 sound. An internal 9-minute timer can be used for a Hush mode. Package Type 16-Lead SOIC V 1 16 LX SS IRED 2 15 V BST V 3 14 HS BAT TEST 4 13 HB TEST2 5 12 IO IRP 6 11 IRCAP IRN 7 10 FEED RLED89 GLED 2019-2020 Microchip Technology Inc. DS20006214B-page 1RE46C194 Functional Block Diagram LX (16) TEST2 (5) Boost Control TEST (4) Current Sense POR and Boost Comparator V (3) BAT BIAS V Low Battery + REF Comparator V (15) BST RLED (8) Control Logic and Timing IRP (6) Photo ADC GLED (9) Integrator (6-Bit) IRN (7) Horn Driver V BST Setup and Limit HB (13) V Precision REF IRCAP (11) IRCAP EEPROM Reference HS (14) FEED (10) Trimmed Programmable IRED (2) Oscillator V IRED Current BST V (1) SS Interconnect IO (12) DS20006214B-page 2 2019-2020 Microchip Technology Inc. +