Description
The A5366 is a low-current BiCMOS circuit providing all of
the required features for a photoelectric type smoke detector.
This device can be used with an infrared photoelectric chamber
to sense scattered light from smoke particles. A networking
capability allows as many as 50 units to be interconnected so
that if any unit senses smoke all units will sound an alarm.
Special features are incorporated in the design to facilitate
calibration and testing of the finished detector. The device is
recognized by Underwriters Laboratories for use in smoke
alarms that comply with Standard UL217.
A variable-gain photoamplifier can be directly interfaced to
an infrared emitter-detector pair. The amplifier gain levels are
determined by two external capacitors and are 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 approximately 10% to reduce false
triggering. High gain is used during pushbutton test and to
periodically monitor the chamber sensitivity during standby.
The internal oscillator and timing circuitry keep standby power
to a minimum by sensing for smoke for only 100 s every 10 s.
A special three-stage–speedup sensing scheme is incorporated
to minimize the time to an audible alarm and also to reduce
false triggering. Chamber sensitivity is periodically monitored
and two consecutive cycles of degraded sensitivity are required
for a warning signal (chirp) to occur.
The A5366 is supplied in a 16-pin dual in-line plastic package
(suffix A), and for surface mount, a 16-pin SOICW (suffix
LW). The lead (Pb) free versions (suffix –T) have 100% matte-
tin leadframe plating. The devices are rated for continuous
operation over the temperature range of –25°C to 75°C.
26110.11-DS, Rev. E
Features and Benefits
Low average standby current for long battery life
Interconnect up to 50 detectors
Piezoelectric horn driver
Low battery detection (all internal)
Chamber sensitivity test and alarm
Power-on reset (POR)
Internal timer and control for reduced sensitivity mode
Built-in circuits to reduce false triggering
6 to 12 V operating range
ESD protection circuitry on all pins
Temporal Horn Pattern, per UL217, NFPA72, and ISO8201
UL Recognized for UL217 applications, per file #S2113
Photoelectric Smoke Detector
with Interconnect and Timer
Packages:
Not to scale
A5366
16-pin DIP
(Package A)
16-pin SOICW
(Package LW)
Typical Application Diagram
C1
C2
DETECT
STROBE
VDD
IRED
HORN1 HORN2
I/O
FEEDBACK
LED
OSC CAP
TIMING RES
VSS
HUSH
TEST
A5366
To / from
other units
220 Ω
Rx2
Rx1
100 μF
1 kΩ
4.7 kΩ
5 kΩ
4700 pF
0.047 μF
560 Ω
200 kΩ
220 kΩ
1.5 MΩ
1000 pF
100 kΩ
10 MΩ
330 Ω
1500 pF
Red LED
Push-to-Test
9 V
22 μF
Connect HUSH to VSS
to disable timer mode
Value of component can vary,
based on the piezoelectric horn used
Connect to allow timer mode
("hush") operation
Piezo Horn
8.2 kΩ
VDD
22 Ω
Smoke
Chamber
B
C
C
C
C
B
A
A
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
2
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Selection Guide
Part Number Pb-free Package Packing
A5366CA – 16-pin DIP through hole 25 pieces / tube
A5366CA-T Yes 16-pin DIP through hole 25 pieces / tube
A5366CLWTR-T Yes 16-pin SOICW surface mount 1000 pieces / reel
Absolute Maximum Ratings*
Characteristic Symbol Notes Rating Units
Supply Voltage Range VDD Referenced to VSS –0.5 to 15 V
Input Voltage Range VIN Referenced to VSS –0.3 to VDD+0.3 V
Input Current IIN 10 mA
Operating Ambient Temperature Range TARange C –25 to 75 ºC
Maximum Junction Temperature TJ(max) 150 ºC
Storage Temperature Range Tstg –55 to 125 ºC
*CAUTION: CMOS devices have input static protection but are susceptible to damage if exposed to extremely high static electrical charges.
Terminal List Table
Number Name Function
1 C1 Sets photoamplifier gain in supervisory mode
2 C2 Sets photoamplifier gain in standby mode
3 DETECT Photoamplifier input
4 STROBE Strobed supply (VDD – 5 V) for photoamplifier low-side
reference
5 VDD Positive supply voltage
6 IRED Output to smoke chamber IR LED driver
7 I/O Input-output to interconnected detectors
8 HORN1 Output for driving piezoelectric horn
9 HORN2 Complementary output for driving piezoelectric horn
10 FEEDBACK Input for driving piezoelectric horn
11 LED Output to drive visible LED
12 OSC CAP Connection for capacitor to set clock frequency
13 TIMING RES Connection for resistor to set clock frequency
14 VSS Negative supply voltage
15 HUSH Input for photoamplifier timer mode reference; can also
disable timer mode
16 TEST Enables push-to-test mode and diagnostic test/calibration
mode; starts timer mode, if enabled
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
TEST
HUSH
VSS
TIMING RES
OSC CAP
LED
FEEDBACK
HORN2
C1
C2
DETECT
STROBE
VDD
IRED
I/O
HORN1
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
TEST
HUSH
VSS
TIMING RES
OSC CAP
LED
FEEDBACK
HORN2
C1
C2
DETECT
STROBE
VDD
IRED
I/O
HORN1
Package A
Package LW
Pin-out Diagrams
Thermal Characteristics
Characteristic Symbol Test Conditions* Value Units
Package Thermal Resistance RθJA
Package A, on 4-layer PCB based on JEDEC standard 38 ºC/W
Package LW, on 4-layer PCB based on JEDEC standard 48 ºC/W
*Additional thermal information available on Allegro website.
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
3
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Band-gap
Reference
Low Battery
Photoamp
9 V
Logic
Oscillator
and Timing
Power-On
Reset
VDD
VDD
VDD
VDD
VDD
I/O
FEEDBACK
HORN1
HORN2
LED
TIMING RES
OSC CAP
TESTHUSH
VSS
IRED
STROBE
C2
C1
DETECT
+Supply
–Supply
+
_
+
_
Functional Block Diagram
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
4
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
DC ELECTRICAL CHARACTERISTICS at TA = –25°C to 75°C1. VSS = 0 V, in typical ap pli ca tion (un less oth er wise noted)
Characteristic Symbol Test Conditions Test Pin VDD Min. Typ.2Max. Units
Supply Voltage Range VDD 5 – 6.0 – 12 V
Operating Supply Current IDD
Average in standby mode, configured per
typical application 512––9μA
During STROBE on, IRED off, configured per
typical application 5 12 – – 2.0 mA
During STROBE on, IRED on, configured per
typical application 5 12 – – 3.0 mA
Low-Level Input Voltage VIL
7 9 – – 1.5 V
10 9 – – 2.7 V
16 9 – – 7.0 V
15 9 – – 0.5 V
High-Level Input Voltage VIH
7 9 3.2 – – V
10 9 6.3 – – V
16 9 8.5 – – V
15 9 1.6 – – V
Input Leakage High IIH
VIN = VDD, STROBE active, OSC CAP = VDD 1, 2 12 – – 100 nA
VIN = VDD 3, 10, 12 12 – – 100 nA
Input Leakage Low IIL
VIN = VST, STROBE active, OSC CAP = VDD 1, 2, 3 12 – – –100 nA
VIN = VSS
10, 12 12 – – –100 nA
15, 16 12 – – –1.0 μA
Input Pull-Down Current IIN
VIN = VDD 16, 15 9 0.25 – 10 μA
No local smoke, VIN = VDD 7 9 20 – 80 μA
No local smoke, VIN = 17 V 7 12 – – 140 μA
Low-Level Output Voltage VOL
IO = 10 mA 11 6.5 – – 0.6 V
IO = 16 mA 8, 9 6.5 – – 1.0 V
IO = 5 mA 13 6.5 – 0.5 – V
High-Level Output Voltage VOH IO = –16 mA 8, 9 6.5 5.5 – – V
Strobe Output Voltage VST
Inactive, IO = –1 μA412
VDD
– 0.1 ––V
Active, IO = 100 to 500 μA49
VDD
– 5.25 –VDD
– 4.75 V
Line Regulation ΔVST(ΔVDD) Active, VDD = 6 to 12 V 4 – – –60 – dB
Strobe Temperature
Coefficient αST VDD = 6 to 12 V 4 – – 0.01 – %/°C
IRED Output Voltage VIRED
Inactive, IO = 1 μA, TA = 25°C 6 12 – – 0.1 V
Active, IO = –6 mA, TA = 25°C 6 9 2.85 3.1 3.35 V
Continued on the next page…
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
5
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Line Regulation ΔVIRED(ΔVDD) Active, VDD = 6 to 12 V 6 – –35 – dB
IRED Temperature Coefficient αIRED VDD = 6 to 12 V 6 – – 0.40 – %/°C
High-Level Output Current IOH VDD = Alarm, I/O active,VO = VDD – 2 V 7 9 –4.0 – – mA
OFF Leakage Current High IOZ VO = VDD 11, 13 12 – – 1.0 μA
OFF Leakage Current Low IOZ VO = VSS 11, 13 12 – – –1.0 μA
Low-Battery Alarm Threshold VDD(th) 5 – 6.9 7.2 7.5 V
Common Mode Voltage VIC Any alarm condition 1, 2, 3 - VDD
– 4 –VDD
– 2 V
Smoke Comparator
Reference Voltage VREF Any alarm condition Internal - VDD
– 3.7 –VDD
– 3.3 V
1Limits over the operating temperature range are based on characterization data. Characteristics are production tested at 25°C only.
2Typical values are at 25°C and are given for circuit design information only.
DC ELECTRICAL CHARACTERISTICS (continued) at TA = –25°C to 75°C1, VSS = 0 V, in typical ap pli ca tion (un less oth er wise noted)
Characteristic Symbol Test Conditions Test Pin VDD Min. Typ.2Max. Units
AC ELECTRICAL CHARACTERISTICS at TA = –25°C to 75°C1. VSS = 0 V, in typical ap pli ca tion (un less oth er wise noted)
Characteristic Symbol Test Conditions Test Pin VDD Min. Typ.2Max. Units
Oscillator Period tosc 12 9 9.4 10.5 11.5 ms
LED Pulse Period
tled1 No local or remote smoke 11 9 39 – 48 s
tled3 Local smoke 11 9 0.45 0.50 0.55 s
tled4 Remote smoke only 11 9 – No LED
Pulses –s
tled6 Pushbutton test, induced alarm 11 9 0.45 0.50 0.55 s
tled7 Timer mode, no alarm 11 9 9.67 10.75 11.83 s
LED Pulse Width tw(led) 11 9 9.5 – 11.5 ms
STROBE Pulse Period
tst1 No local or remote smoke 4 9 9.6 – 11.9 s
tst2 After 1 of 3 valid samples 4 9 1.8 2.0 2.2 s
tst3
After 2 of 3 valid samples and during local
alarm 4 9 0.8 1.0 1.1 s
tst4 Remote smoke only 4 9 7.2 8.0 8.9 s
tst5
Chamber test or low battery test, no local
alarm 4 9 38.9 – 47.1 s
tst6 Pushbutton test, induced alarm 4 9 225 252 278 ms
STROBE Pulse Width tw(st) 4 9 9.5 – 11.5 ms
Continued on the next page…
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
6
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
IRED Pulse Period
tired1 No local or remote smoke 6 9 9.6 – 11.9 s
tired2 After 1 of 3 valid samples 6 9 1.8 2.0 2.2 s
tired3
After 2 of 3 valid samples and during local
alarm 6 9 0.8 1.0 1.1 s
tired4 Remote smoke only 6 9 7.2 8.0 8.9 s
tired5 Chamber test, no local alarm 6 9 38.9 – 47.1 s
tired6 Pushbutton test, induced alarm 6 9 225 252 278 ms
IRED Pulse Width tw(ired) 6 9 94 – 116 μs
IRED Rise Time tr(ired) 10% to 90% 6 – – 30 μs
IRED Fall Time tf(ired) 90% to 10% 6 – – 200 μs
I/O to Active Delay td(io) Local alarm 7 9 – 0 – s
I/O Charge Dump Duration tdump End of local alarm or test 7 9 0.9 1.0 1.1 s
Rising Edge on I/O to Alarm tr(io) No local alarm 7 9 – – 128 ×
tOSC s
Horn Warning Pulse Period thorn Low battery or degraded chamber sensitivity 8, 9 9 38.9 – 47.1 s
Horn Warning Pulse Width tw(horn) Low battery or degraded chamber sensitivity 8, 9 9 9.5 – 11.5 ms
Horn On-Time ton(horn) Local or remote alarm 8, 9 9 450 500 550 ms
Horn Off-Time
toff1(horn)
Local or remote alarm (see Timing Diagrams
section) 8, 9 9 450 500 550 ms
toff2(horn)
Local or remote alarm (see Timing Diagrams
section) 8, 9 9 1350 1500 1650 ms
1Limits over the operating temperature range are based on characterization data. Characteristics are production tested at 25°C only.
2Typical values are at 25°C and are given for circuit design information only.
AC ELECTRICAL CHARACTERISTICS (continued) at TA = –25°C to 75°C1, VSS = 0 V, in typical ap pli ca tion (un less oth er wise noted)
Characteristic Symbol Test Conditions Test Pin VDD Min. Typ.2Max. Units
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
7
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Pin and Circuit Description
(In Typical Application)
C1 Pin
A capacitor connected to this pin determines the gain, Ae, of
the photoamplifier during the push-to-test mode and during the
chamber monitor test. A typical capacitor value for this high-
gain (supervisory) mode is 0.047 F, but it should be selected
based on the photochamber background reflections reaching the
detector and the desired level of sensitivity. Ae = 1 + (C1
/ 10),
where C1 is in pF. Ae should not exceed 10,000 and thus C1
should not exceed 0.1 F. Coupling of other signals to the C1,
C2, and DETECT inputs must be minimized.
C2 Pin
A capacitor connected to this pin determines the gain, Ae, of
the photoamplifier during standby. A typical capacitor value for
this low-gain mode is 4700 pF, but it should be selected based
on a specific photochamber and the desired level of sensitiv-
ity to smoke. Ae = 1 + (C2
/ 10), where C2 is in pF. Ae should not
exceed 10,000 and thus C2 should not exceed 0.1 F. This gain
increases by a nominal 10% after a local alarm is detected (three
consecutive detections). A resistor must be installed in series
with the C2 capacitor.
DETECT Pin
This is the input to the photoamplifier and is connected to the
cathode of the photodiode. The photodiode is operated at zero
bias and should have low dark leakage current and low capaci-
tance. A shunt resistor must be installed in parallel with the
photodiode.
STROBE Pin
This output provides a strobed, regulated voltage of VDD – 5 V.
The minus side of all internal and external photoamplifier cir-
cuitry is referenced to this pin.
VDD Pin
This pin is connected to the positive supply potential and can
range from 6 to 12 V with respect to VSS.
IRED Pin
This output provides a pulsed base current for the external NPN
transistor, which drives the IR emitter. Its beta should be greater
than 100. To minimize noise impact, the IRED output is not
active when the horn and visible LED outputs are active.
I/O Pin
A connection at this pin allows multiple smoke detectors to be
interconnected. If any single unit detects smoke, its I/O pin is
driven high, and all connected units will sound their associated
horns. As an input, this pin is sampled every 128 clock cycles
(nominally 1.34 s) during standby. The LED is suppressed when
an alarm is signaled from an interconnected unit, and any local-
alarm condition causes this pin to be ignored as an input. An
internal NMOS device acts as a charge dump to aid in applica-
tions involving a large (distributed) capacitance, and is activated
at the end of a local or test alarm. This pin has an on-chip pull-
down device and must be left unconnected if not used. In the
application, there should be a series current-limiting resistor to
other smoke alarms.
HORN1, HORN2, and FEEDBACK Pins
These three pins are used with a self-resonating piezoelectric
transducer and horn-starting external passive components. The
output HORN1 is connected to the piezo metal support elec-
trode. The complementary output, HORN2, is connected to the
ceramic electrode. The FEEDBACK input is connected to the
feedback electrode. If the FEEDBACK pin is not used, it must
be connected to VSS.
LED Pin
This open-drain NMOS output is used to directly drive a visible
LED. The load for the low-battery test is applied to this output.
If an LED is not used, it should be replaced with an equivalent
resistor (typically 500 to 1000 ) such that the battery load-
ing remains about 10 mA. The low-battery test does not occur
coincident with any other test or alarm signal. The LED also
indicates detector status as follows (with component values as in
the typical application, all times nominal):
Condition Pulse Occurrence
Standby Every 43 s
Local Smoke Every 0.5 s
Remote Alarm No pulses
Test Mode Every 0.5 s
Timer Mode Every 10 s
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
8
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
OSC CAP (Oscillator Capacitor) Pin
A capacitor between this pin and VDD, along with a parallel
resistor, forms part of a two-terminal oscillator and sets the inter-
nal clock low time. With component values shown, this nominal
time is 10.4 ms and essentially the oscillator period. The internal
clock low time can be calculated by:
Tlow = 0.693 × ROSCCAP × COSCCAP .
TIMING RES (Timing Resistor) Pin
A resistor between this pin and OSC CAP is part of the two-ter-
minal oscillator and sets the internal clock high time, which is
also the IRED pulse width. With component values shown, this
time is nominally 105 s. The internal clock high time can be
calculated by:
Thigh = 0.693 × RTIMINGRES × COSCCAP .
VSS Pin
This pin is connected to the negative supply potential (usually
ground).
HUSH Pin
This input pin has an internal pull-down device and serves two
purposes in standby mode. It serves to enable/disable entering
the internal 10-minute (nominal) “hush” timer mode, and also
as the reference for the smoke comparator during timer mode.
When the voltage on this pin is greater than 1.5 V, entering timer
mode is enabled, and a high-to-low transition on TEST resets
and starts timer mode. If use of timer mode is not desired, this
pin can be connected to VSS or left open, and a voltage of less
than 0.5 V on the pin will disable timer mode. During timer
mode, the smoke comparator reference is established by a resis-
tive divider (Rx1 and Rx2) between the VDD and STROBE
pins and allows the detector to operate with reduced sensitivity
during timer mode. This allows the user to hush alarms caused
by nuisance smoke or steam (such as from cooking). When not
in timer mode, the smoke comparator reference is set internally
to approximately VDD – 3.5 V.
TEST Pin
This pin has an internal pull-down device and is used to manu-
ally invoke two test modes and timer mode.
Push-to-Test mode is initiated by a voltage greater than approxi-
mately VDD – 0.5 V on this pin (usually the depression of a
normally-open pushbutton switch to VDD). After one oscilla-
tor cycle, the amplifier gain is increased by internal selection
of C1 so that background reflections in the smoke chamber can
be used to simulate a smoke condition, and IRED pulses every
252 ms (nominal). After the third IRED pulse (three consecu-
tive simulated smoke conditions), the successful test activates
Table 1. Alternate Pin Configuration During Diagnostic
Test/Calibration Mode
Pin Name Alternate Configuration
I/O
Disabled as an output. A logic high on this pin places the
photoamplifier output on pin C1 or C2 as determined by
the HUSH pin. The amplifier output appears as pulses.
HUSH
If the I/O pin is high, this pin controls the amplifier gain
capacitor. If this pin is low, normal gain is selected and
the amplifier output is on pin C1. If this pin is high,
supervisory gain is selected and the amplifier output is
on pin C2.
FEED-
BACK
If the I/O pin is high and the HUSH pin is low (normal
gain), taking this pin to a high logic level increases the
amplifier gain by ≈10% (hysteresis).
OSC CAP
This pin may be driven by an external clock source.
Driving this pin low and high drives the internal clock low
and high. The external RC network may remain intact.
HORN1
This pin is reconfigured as the smoke integrator output.
Three consecutive smoke detections will cause this pin
to go high and three consecutive no-smoke detections
cause this pin to go low.
LED
This pin becomes a low-battery indicator. The open-drain
NMOS output is normally off. If VDD falls below the low-
battery threshold, the output turns on.
the horn drivers and the I/O pin, and the LED blinks once every
0.5 s. If the test fails, the LED will not blink, the horn will not
sound, and the I/O pin will remain low. When the pushbutton is
released, the input returns to VSS due to the internal pull down.
After one oscillator cycle, the amplifier gain returns to normal,
and after three additional IRED pulses (less than one second), the
device exits this mode and returns to standby. This high-to-low
transition on TEST also resets and starts the 10-minute (nominal)
“hush” timer mode, if the mode is enabled via the HUSH pin.
Diagnostic Test/Calibration Mode is available to facilitate
calibration and test of the IC and the assembled detector. It is
initiated by pulling TEST below VSS by continuously drawing
400 A from the pin for at least one clock cycle on OSC CAP.
The current should not exceed 800 A and under these condi-
tions, TEST pin voltage will clamp at approximately one diode
drop below VSS. One option is to connect TEST to a –5 V supply
through a 12 k resistor. In this mode, certain device pins are
reconfigured as described in table 1. The IRED pulse rate is
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
9
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
increased to one pulse every OSC CAP cycle and the STROBE
pin is always active. To exit this mode, the TEST pin should be
floated, or returned to VSS, for at least one OSC CAP cycle.
Alarm Indications
Alarm conditions include: local smoke detection, a remote alarm,
low battery, or degraded chamber sensitivity. These are indicated
by a combination of horn and LED signals, which continue until
the alarm condition is resolved. A local alarm always overrides
a remote alarm, and a local or remote alarm will inhibit warning
signals for low battery or degraded chamber.
During a local or a remote alarm condition, the horn output is a
continuous modulated tone (temporal horn pattern), nominally:
0.5 s on, 0.5 s off, 0.5 s on, 0.5 s off, 0.5 s on, and 1.5 s off. The
visible LED distinguishes a local alarm from a remote alarm.
During a local alarm, the LED blinks every 0.5 s (nominally), but
during a remote alarm, the LED is disabled and does not blink.
The degraded-chamber test occurs periodically (nominally every
43 s). During this test, the gain of the photoamplifier is switched
to the high (supervisory) level, set by C1. The device expects
that the photodiode will receive enough reflected background
light in the chamber to cause an alarm condition. If a faulty, dirty,
or obstructed chamber prevents this for two consecutive tests,
the device signals degraded chamber with one short (nominally
10 ms) horn chirp every 43 s, essentially halfway between LED
flashes. The condition is resolved when the chamber is either
cleared or cleaned.
The low-battery test also occurs periodically (also nominally
every 43 s, but offset from the degraded-chamber test). Dur-
ing this test, the load of the LED is applied to the battery, and
a resistive divider off VDD is compared to an internal band-gap
reference. If VDD is below the threshold, the device signals low
battery with one short (nominally 10 ms) horn chirp every 43 s,
occurring almost simultaneously with the visible LED flash. The
condition is resolved when the battery is replaced.
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
10
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Timing Diagrams
(Not to Scale)
Standby Mode
Low Battery Condition
Degraded Chamber Condition
OSC CAP Pin
STROBE Pin
IRED Pin
LED Pin
LED Pin
LED Pin
Internal Clock
Test event
Horn Enable
VDD Pin
Chamber
Sensitivity
Photo Sample
Chamber Test
Low-Battery Test
Low-Battery Test
Chamber Test
Horn Enable
tosc
tw(st)
tw(led)
tw(horn)
tw(horn)
thorn
thorn
Chirps occur at the end of a failed “test period,” and are nearly coincident with LED flashes
Chirps occur after 2 consecutive failed tests, and are offset from LED flashes and from chirps that indicate failure of low-battery tests
tst1, tired1
tst5, tired5
tled1, tst5
LED off (High-Z)
LED on
LED off
(High-Z)
LED on
LED off
(High-Z)
LED on
(Low battery)
Failed “test period”
(Degraded chamber)
10%
50%
90%
tw(ired)
tf(ired)
tr(ired)
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
11
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Horn Enable
ton(horn) toff1(horn)
toff2(horn)
I/O Pin
LED Pin
tt
st2, ired2
tw(led)
3rd strobe without smoke
STROBE Pin
IRED Pin
tw(st)
tdump
O Charge Dump/I
tdump
O Charge Dump/I
(Output)
(Input)
Horn Enable
I/O Pin
ton(horn) toff1(horn)
toff2(horn)
tr(io)
tw(st)
STROBE Pin
LED Pin
LED Pin
Horn Enable
I/O Pin
STROBE Pin
TEST Pin
ton(horn) toff1(horn)
toff2(horn)
(Output)
tw(st)
tw(led) tled6
tled3
tst3, ired3
t tst3, ired3
t
tst4, ired4
t
tst6, ired6
t
1st strobe with smoke 3rd strobe with smoke
LED off (High-Z)
LED off (High-Z)
LED on
LED off (High-Z)
LED on
Local Smoke Detection Alarm Condition
Remote Alarm Condition
Test Alarm Mode
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
12
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Package A, 16-Pin DIP
2
.750 [19.05]
.250 [6.35] .430 [10.92]
.210 [5.33] MAX
.300 [7.62]
.010 [0.25]
.018 [0.46]
.100 [2.54]
.130 [3.30]
.060 [1.52]
.005 [1.27]
1
16
A
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
ATerminal #1 mark area
All dimensions nominal, not for tooling use
(reference JEDEC MS-001 BB)
Dimensions in inches, metric dimensions (mm) in brackets, for reference only
Package LW, 16-Pin SOIC
4º
10.30
10.30
0.27
0.84
0.25
2.65 MAX
0.20
1.27 0.41
7.50
C
SEATING
PLANE
C0.10
16X
21
16
GAUGE PLANE
SEATING PLANE
All dimensions nominal, not for tooling use
Dimensions in millimeters
(reference JEDEC MS-013 AA)
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
ATerminal #1 mark area
A
Photoelectric Smoke Detector
with Interconnect and Timer
A5366
13
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
For the latest version of this document, visit our website:
www.allegromicro.com
Allegro MicroSystems offers an industry-leading range of ionization
and photoelectric smoke detector ICs. For a current listing, please visit
our website at:
www.allegromicro.com
Copyright ©2001-2007, Allegro MicroSystems, Inc.
The products described herein are manufactured under one or more of the following U.S. patents: 5,045,920; 5,264,783; 5,442,283; 5,389,889;
5,581,179; 5,517,112; 5,619,137; 5,621,319; 5,650,719; 5,686,894; 5,694,038; 5,729,130; 5,917,320; and other patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to per-
mit improvements in the per for mance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the
information being relied upon is current.
Allegro’s products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the
failure of that life support device or system, or to affect the safety or effectiveness of that device or system.
The in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon si bil i ty for its use;
nor for any in fringe ment of patents or other rights of third parties which may result from its use.
