RE46C145 Datasheet, PDF (1/12 Pages) Microchip Technology – CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode

R&E International
A Subsidiary of Microchip Technology Inc.
RE46C145
CMOS Photoelectric Smoke Detector ASIC with Interconnect and Timer Mode
Product Specification
General Description
The RE46C145 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 10 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.
In the diagnostic mode the photo amplifier output is
available on pin 15 for production calibration of the
photo chamber.
A check for a low battery condition and chamber
integrity is performed every 43 seconds when in
standby. The temporal horn pattern supports the NFPA
72 emergency evacuation signal.
An interconnect pin allows multiple detectors to be
connected such that when one units alarms, all units
will sound.
An internal 10 minute timer can be used for a reduced
sensitivity mode.
Utilizing low power CMOS technology the RE46C145
was designed for use in smoke detectors that comply
with Underwriters Laboratory Specification UL217 and
UL268.
ABSOLUTE
MAXIMUM
RATINGS
PARAMETER
Supply Voltage
Input Voltage Range
Except FEED, IO
FEED Input Voltage
Range
IO Input Voltage
SYMBOL
V_DD
V_in
V_infd
V_io1
VALUE
15
-.3 to V_dd
+.3
-10 to
+22
-.3 to 17
UNITS
V
V
V
V
© 2009 Microchip Technology Inc.
Features
• Internal Power On Reset
• Low Quiescent Current Consumption
• Available in 16L PDIP or 16L N SOIC
• ESD Protection on all Pins
• Interconnect up to 40 Detectors
• 10 Minute Timer for Sensitivity Control
• Temporal Horn Pattern
• Internal Low Battery and Chamber Test
• Compatible with Allegro A5366
• Alternate Diagnostic Mode
• Available in Standard Packaging or RoHS
Compliant Pb Free Packaging.
Pin Configuration
C1
1
C2
2
DETECT ₃
STROBE
4
VDD 5
IRED 6
IO ₇
HORNB
8
16 ^TEST
15 ^VSEN
14 ^VSS
13 ^ROSC
12 ^COSC
11 ^LED
10 ^FEED
9 ^HORNS
Range
Input Current except
FEED
Operating
Temperature
Storage Temperature
Maximum Junction
Temperature
I_in
T_A
T_STG
T_J
10
mA
-25 to 75
°C
-55 to
°C
125
150
°C
DS22181A-page 1