RE46C190S16TF Microchip

RE46C190 CMOS Low Voltage Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode Features Description Two AA Battery Operation The RE46C190 is a low power, low voltage CMOS photoelectric type smoke detector IC. With minimal Internal Power On Reset external components, this circuit will provide all the Low Quiescent Current Consumption required features for a photoelectric-type smoke Available in 16L N SOIC detector. Local Alarm Memory The design incorporates a gain-selectable photo Interconnect up to 40 Detectors amplifier for use with an infrared emitter/detector pair. 9 Minute Timer for Sensitivity Control An internal oscillator strobes power to the smoke Temporal or Continuous Horn Pattern detection circuitry every 10seconds, to keep the Internal Low Battery and Chamber Test standby current to a minimum. If smoke is sensed, the All Internal Oscillator detection rate is increased to verify an Alarm condition. A high gain mode is available for push button chamber Internal Infrared Emitter Diode (IRED) driver testing. Adjustable IRED Drive current Adjustable Hush Sensitivity A check for a low battery condition is performed every 86 seconds, and chamber integrity is tested once every 2% Low Battery Set Point 43 seconds, when in Standby. The temporal horn pat- tern supports the NFPA 72 emergency evacuation sig- nal. An interconnect pin allows multiple detectors to be connected such that, when one unit alarms, all units will sound. An internal 9 minute timer can be used for a Reduced Sensitivity mode. Utilizing low power CMOS technology, the RE46C190 was designed for use in smoke detectors that comply with Underwriters Laboratory Specification UL217 and UL268. PIN CONFIGURATION RE46C190 SOIC V 1 16 LX SS IRED 2 15 V BST V 3 14 HS DD TEST HB 4 13 TEST2 5 12 IO 6 11 IRP IRCAP IRN 7 10 FEED RLED 8 9 GLED 2010 Microchip Technology Inc. DS22271A-page 1RE46C190 TYPICAL BLOCK DIAGRAM TEST2 (5) LX (16) TEST (4) Boost Control Precision Reference Current Sense V (3) DD Low Battery Comparator R3 + Boost Comparator - + R4 Smoke - V (15) BST Comparator RLED (8) + Control - Logic and Timing Level IRP (6) Photo Shift Integrator IRN (7) Horn Driver Trimmed HB (13) + Oscilator - IRCAP (11) POR and HS (14) BIAS High Programmable Normal FEED (10) Limits Hysteresis Interconnect IO (12) Programming GLED (9) Control IRED (2) Programmable IRED Current V (1) SS DS22271A-page 2 2010 Microchip Technology Inc.