A5366
Photoelectric Smoke Detector
with Interconnect and Timer
Timing Diagrams
(Not to Scale)
Standby Mode
OSC CAP Pin
Internal Clock
t
osc
Test event
90%
50%
10%
t
r(ired)
t
f(ired)
t
w(ired)
Photo Sample
Low-Battery Test
Chamber Test
t
w(st)
t
st1
, t
ired1
t
led1
, t
st5
t
st5
, t
ired5
STROBE Pin
IRED Pin
LED Pin
t
w(led)
LED on
LED off (High-Z)
Low Battery Condition
VDD Pin
Low-Battery Test
Failed “test period”
Horn Enable
t
w(horn)
t
horn
(Low battery)
LED Pin
LED on
LED off
(High-Z)
Chirps occur at the end of a failed “test period,” and are nearly coincident with LED flashes
Degraded Chamber Condition
Chamber
Sensitivity
Chamber Test
t
horn
(Degraded chamber)
Horn Enable
t
w(horn)
LED Pin
LED on
LED off
(High-Z)
Chirps occur after 2 consecutive failed tests, and are offset from LED flashes and from chirps that indicate failure of low-battery tests
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
10
SENSITRON [ SENSITRON ]
