RE46C146 Datasheet, PDF (1/13 Pages) Microchip Technology – CMOS Photoelectric Smoke Detector ASIC with Intelligent Interconnect and Timer Mode

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RE46C146
CMOS Photoelectric Smoke Detector ASIC with Intelligent Interconnect and Timer Mode
Product Specification
General Description
The RE46C146 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 for a smoke alarm
condition 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. The interconnect is compatible with certain
types of CO interconnect signaling and when
recognized will sound the temporal pattern for a carbon
monoxide alarm.
An internal 10 minute timer can be used for a reduced
sensitivity mode.
• 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 for Smoke and CO
• 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
Utilizing low power CMOS technology the RE46C146
was designed for use in smoke detectors that comply
with Underwriters Laboratory Specification UL217 and
UL268.
Features
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Supply Voltage
Input Voltage Range Except FEED, IO
FEED Input Voltage Range
IO Input Voltage Range
Input Current except FEED
Operating Temperature
Storage Temperature
Maximum Junction Temperature
SYMBOL
V_DD
V_in
V_infd
V_io1
I_in
T_A
T_STG
T_J
VALUE
12.5
-.3 to V_dd +.3
-10 to +22
-.3 to 17
10
-25 to 75
-55 to 125
150
UNITS
V
V
V
V
mA
°C
°C
°C
© 2009 Microchip Technology Inc.
DS22176A-page 1