PHOTOELECTRIC SMOKE DETECTOR
WITH INTERCONNECT AND TIMER
The A5366CA is a low-current BiCMOS circuit providing all of the
required features for a photoelectric type smoke detector. This device
can be used in conjunction with an infrared photoelectric chamber to
sense scattered light from smoke particles. Special features are
incorporated in the design to facilitate calibration and testing of the
finished detector. The device is designed to comply with Underwriters
Laboratories Specification UL217.
A variable-gain photo amplifier can be directly interfaced to an
infrared emitter/detector pair. The amplifier gain levels are determined
by two external capacitors that are then internally selected depending
on the operating mode. Low gain is selected during standby and timer
modes. During a local alarm this low gain is increased (internally) by
~10% to reduce false triggering. High gain is used during the push-
button test and during standby to periodically monitor the chamber
sensitivity.
The internal oscillator and timing circuitry keeps standby power to
a minimum by sensing for smoke every 10 seconds in a 100 µs
window. A special three-stage speedup sensing scheme is incorpo-
rated to minimize the time to an audible alarm and also to reduce false
triggering. Also, two consecutive cycles of degraded chamber sensitiv-
ity are required for a warning signal to occur.
The A5366CA is supplied in a low-cost 16-pin dual in-line plastic
package. It is rated for continuous operation over the temperature
range of -25°C to +75°C.
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2
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89
10
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OSC. &
TIMING
HORN
DRIVER
TEST
DETECT
HUSH
OSC. CAP.
HORN
HORN
– SUPPLYV
SS
C
I / O
C
STROBE
+ SUPPLY V
DD
TIMING RES.
FEEDBACK
1 2
LEDIRED
LOGIC
1
2
Data Sheet
26110.11*
Dwg. PC-007
ABSOLUTE MAXIMUM RATINGS
(Voltages are referenced to V
SS
)
Supply Voltage Range,
V
DD
.................................... -0.5 V to +15 V
Input Voltage Range,
V
IN
............................ -0.3 V to V
DD
+ 0.3 V
Input Current, I
IN
................................... 10 mA
Operating Temperature Range,
T
A
..................................... -25°C to +75°C
Storage Temperature Range,
T
S
................................... -55°C to +125°C
CAUTION: CMOS devices have input static
protection but are susceptible to damage if exposed
to extremely high static electrical charges. Always order by complete part number: A5366CA .
FEATURES
a73 Interconnect Up to 50 Detectors
a73 Piezoelectric Horn Driver
a73 All Internal Low-Battery Detection
a73 Power-ON Reset
a73 Internal Timer & Control for Reduced Sensitivity
a73 Built-In Circuits to Reduce False Triggering
a73 6 V to 12 V Operating Voltage Range
a73 ESD-Protection Circuitry on All Pins
a73 Temporal Horn Pattern
5366
The selectable Hush Feature may be covered
by U.S. patent number Re. 33,920. Any sale
or use of the Hush Feature in a smoke alarm
in the U.S. would be a possible infringement
of this patent.