R&E International
A Subsidiary of Microchip Technology Inc.
RE46C143
CMOS Photoelectric Smoke Detector ASIC with Interconnect
Product Specification
© 2009 Microchip Technology Inc. DS22178B-page 1
General Description
The RE46C143 is low power CMOS photoelectric type
smoke detector IC. With minimal external components
this circuit will provide all the required features for a
photoelectric type smoke detector.
The design incorporates a gain selectable photo
amplifier for use with an infrared emitter/detector pair.
An internal oscillator strobes power to the smoke
detection circuitry for 100us every 8.1 seconds to keep
standby current to a minimum. If smoke is sensed the
detection rate is increased to verify an alarm condition.
A high gain mode is available for push button chamber
testing.
A check for a low battery condition and chamber
integrity is performed every 40 seconds when in
standby. The alarm horn pattern utilizes a 75% duty
cycle.
An interconnect pin allows multiple detectors to be
connected such that when one units alarms, all units
will sound.
The RE46C143 is recognized by Underwriters
Laboratories for use in smoke detectors that comply
with specification UL217 and UL268.
Features
• Internal Power On Reset
• Low Quiescent Current Consumption
• Available in 16L PDIP, 16L N SOIC or 16L W SOIC
• ESD Protection on all Pins
• Interconnect up to 40 Detectors
• 75% Duty Cycle Horn Pattern
• Low Battery and Chamber Test
• Compatible with Motorola MC145010
• UL Recognized per File S24036
• Available in Standard Packaging or RoHS
Compliant Pb Free Packaging.
Pin Configuration
16
TEST
1
C1
2
C2
15
VSS
DETECT
3
14
STROBE
4
ROSC
13
ABSOLUTE MAXIMUM RATINGS
PARAMETER SYMBOL VALUE UNITS
Supply Voltage V
DD
12.5 V
Input Voltage Range Except FEED, IO V
in
-.3 to V
dd
+.3 V
FEED Input Voltage Range V
infd
-10 to +22 V
IO Input Voltage Range V
io1
-.3 to +17 V
Input Current except FEED I
in
10 mA
Operating Temperature T
A
-25 to 75
°C
Storage Temperature T
STG
-55 to 125
°C
Maximum Junction Temperature T
J
150
°C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are
stress ratings only and operation at these conditions for extended periods may affect device reliability.
This product utilizes CMOS technology with static protection; however proper ESD prevention procedures should be used when
handling this product. Damage can occur when exposed to extremely high static electrical charge.
COSC
5
12
VDD
IRED
IO
HORNB
LE
6
D
11
7
FEED
10
HORNS
8 9
