RE46C180
CMOS Programmable Ionization Smoke Detector ASIC with
Interconnect, Timer Mode and Alarm Memory
Features Description
6 12V Operation The RE46C180 is a next generation low power, CMOS
ionization-type, smoke detector IC. With minimal exter-
Low Quiescent Current Consumption
nal components, this circuit will provide all the required
Programmable Standby Sensitivity
features for an ionization-type smoke detector.
Programmable HUSH Sensitivity
An on-chip oscillator strobes power to the smoke
Programmable Hysteresis
detection circuitry for 5 ms every 10 seconds to keep
Programmable Chamber Voltage for Push-to-Test
the standby current to a minimum.
(PTT) and Chamber Test
A check for a Low Battery condition is performed every
Programmable 150 mV Low Battery Set Point
80s and an ionization chamber test is performed once
Internal Ionization Chamber Test
every 320s when in Standby. The temporal horn pattern
Internal Low Battery Test
complies with the National Fire Protection Association
Internal Power-On Reset and Power-up Low
NFPA 72 National Fire Alarm and Signaling Code for
Battery Test
emergency evacuation signals.
Alarm Memory
An interconnect pin allows multiple detectors to be con-
Auto Alarm Locate
nected, such that when one unit alarms, all units will
sound. A charge dump feature quickly discharges the
Horn Synchronization
interconnect line when exiting a Local Alarm condition.
IO Filter and Charge Dump
The interconnect input is also digitally filtered.
Smart Interconnect
An internal 9 minute or 80s timer can be used for a
Interconnect up to 40 Detectors
Reduced Sensitivity mode.
5% All Internal Oscillator
An alarm memory feature allows the user to determine
9 Minute or 80 Second Timer for Sensitivity
whether the unit has previously entered a Local Alarm
Control
condition.
Temporal or Continuous Horn Pattern
Utilizing low-power CMOS technology, the RE46C180
Guard Outputs for Ion Detector Input
is designed for use in smoke detectors that comply with
0.75 pA Detect Input Current
the Standard for Single and Multiple Station Smoke
10-year End-of-Life Indication
Alarms, UL217 and the Standard for Smoke Detectors
for Fire Alarm Systems, UL268.
Package Types
RE46C180
PDIP, SOIC
TEST 1 16 GUARD2
IO DETECT
2 15
3 14
GLED GUARD1
CHAMBER
4 13
T3
5 12
RLED
T2
6 11
V
DD HS
TESTOUT 7 10
HB
FEED 8 9 V
SS
2011-2019 Microchip Technology Inc. DS20002275B-page 1RE46C180
Functional Block Diagram
DS20002275B-page 2 2011-2019 Microchip Technology Inc.
IO (2)
TEST (1)
V (6)
DD
FEED (8)
Low Batt
Trimmable
Comp
Low Batt
+
Trimmable
Reference HS (11)
Logic
Low Batt
and
Setting
Timing
-
Smoke
Comp
Trimmable HB (10)
Smoke
+
Reference
RLED (5)
-
GUARD1 (14)
GLED (3)
+
BIAS, Power Reset
DETECT (15)
and
-
TESTOUT (7)
Test and
Trimmable Oscillator
GUARD2 (16)
Program
T2 (12)
Mode Sel
Guard
T3 (13)
Amp
V (9)
SS
Chamber
Programmable
Voltage
Trim
CHAMBER (4)