R&E International
A Subsidiary of Microchip Technology Inc.
RE46C126
CMOS Ionization Smoke Detector ASIC with Interconnect
Product Specification
© 2009 Microchip Technology Inc. DS22170B-page 1
General Description
The RE46C126 is low power CMOS ionization type
smoke detector IC. With few external components this
circuit will provide all the required features for an
ionization type smoke detector.
An internal oscillator strobes power to the smoke
detection circuitry for 10.5mS every 1.66 seconds to
keep standby current to a minimum. A check for a low
battery condition is performed every 40 seconds when
in standby. A 2/3 duty cycle continuous horn pattern is
used for the alarm condition.
An interconnect pin allows multiple detectors to be
connected such that when one unit alarms all units will
sound.
Although this device was designed for smoke detection
utilizing an ionization chamber it can be used in a
variety of security applications.
The RE46C126 is recognized by Underwriters
Laboratories for use in smoke detectors that comply
with specification UL217 and UL268.
Features
• Guard Outputs for Ion Detector Input
• +/-0.75pA Detect Input Current
• Internal Reverse Battery Protection
• Internal Low Battery Detection
• Low Quiescent Current Consumption (<6.5uA)
• Available in 16L PDIP or 16L N SOIC
• ESD Protection on all Pins
• Interconnect up to 40 Detectors
• Compatible with MC14468
• UL Recognized per File S24036
• Available in Standard Packaging or RoHS
Complaint Pb Free Packaging
Pin Configuration
16
DETCOMP GUARD2
1
2
DETECT IO
15
3
GUARD1LBADJ
14
4
VSENSTROBE
13
ABSOLUTE MAXIMUM RATINGS
PARAMETER SYMBOL VALUE UNITS
Supply Voltage V
DD
15 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
Reverse Battery Time T
RB
5 S
Input Current except FEED I
in
10 mA
Operating Temperature T
A
-10 to 60
°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
OSCAP
5
12
LED
VDD
RBIAS
FEED
6
HS
11
7
HB
10
VSS
8 9
