A5358CLWTR-T [ALLEGRO]
The A5358 is a low-current BiCMOS circuit providing all of the required features for a photoelectric type smoke detector.; 的A5358是低电流的BiCMOS电路的光电式烟雾检测器提供所有需要的特性。型号: | A5358CLWTR-T |
厂家: | ALLEGRO MICROSYSTEMS |
描述: | The A5358 is a low-current BiCMOS circuit providing all of the required features for a photoelectric type smoke detector. |
文件: | 总13页 (文件大小:326K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
A5358
Photoelectric Smoke Detector
with Interconnect and Timer
Features and Benefits
Description
▪ 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
The A5358 is a low-current BiCMOS circuit providing all of
the required features for a photoelectric type smoke detector.
Thisdevicecanbeusedwithaninfraredphotoelectricchamber
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
designed for applications that comply with European Standard
EN 14604 and British Standard BS 5446, Part 1.
▪ ESD protection circuitry on all pins
A variable-gain photoamplifier can be directly interfaced to
an infrared emitter-detector pair. The amplifier gain levels are
determinedbytwoexternalcapacitorsandareinternallyselected
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.
Packages:
16-pin DIP
(Package A)
Theinternaloscillatorandtimingcircuitrykeepstandbypower
to a minimum by sensing for smoke for only 100 μs every 10 s.
Aspecial three-stage–speedup sensing scheme is incorporated
to minimize the time to an audible alarm and also to reduce
falsetriggering. Chambersensitivityisperiodicallymonitored
andtwoconsecutivecyclesofdegradedsensitivityarerequired
for a warning signal (chirp) to occur.
16-pin SOICW
(Package LW)
TheA5358 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.
Not to scale
Typical Application Diagram
VDD
0.047 μF
1
2
9 V
8.2 kΩ
5 kΩ
Rx1
Rx2
C1
C2
16
22 μF
TEST
A5358
Push-to-Test
1500 pF
A
4.7 kΩ
15
560 Ω
HUSH
3
4
5
4700 pF
DETECT
STROBE
Red LED
B
14
13
VSS
VDD
Connect to allow timer mode
("hush") operation
A
B
C
200 kΩ
10 MΩ
TIMING RES
100 kΩ
Connect HUSH to VSS
to disable timer mode
1 kΩ
12
11
6
330 Ω
OSC CAP
LED
IRED
I/O
Smoke
Chamber
Value of component can vary,
based on the piezoelectric horn used
7
8
C
220 kΩ
22 Ω
10
9
FEEDBACK
HORN2
100 μF
1000 pF
C
HORN1
Piezo Horn
220 Ω
1.5 MΩ
C
To / from
other units
26110.10-DS, Rev. I
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
Selection Guide
Part Number
A5358CA
A5358CA-T
A5358CLWTR-T
Pb-free
–
Yes
Package
Packing
25 pieces / tube
25 pieces / tube
1000 pieces / reel
16-pin DIP through hole
16-pin DIP through hole
16-pin SOICW surface mount
Yes
Absolute Maximum Ratings*
Characteristic
Symbol
VDD
Notes
Referenced to VSS
Rating
–0.5 to 15
–0.3 to VDD+0.3
10
Units
V
Supply Voltage Range
Input Voltage Range
Input Current
VIN
Referenced to VSS
V
IIN
mA
ºC
Operating Ambient Temperature Range
Maximum Junction Temperature
Storage Temperature Range
TA
–25 to 75
150
TJ(max)
ºC
T
stg
–55 to 125
ºC
*CAUTION: BiCMOS devices have input static protection but are susceptible to damage if exposed to extremely high static electrical
charges.
Thermal Characteristics
Characteristic
Symbol
Test Conditions*
Value Units
Package A, on 4-layer PCB based on JEDEC standard
38
48
ºC/W
ºC/W
Package Thermal Resistance
RθJA
Package LW, on 4-layer PCB based on JEDEC standard
*Additional thermal information available on Allegro website.
Terminal List Table
Number
Name
Function
Sets photoamplifier gain in supervisory mode
Sets photoamplifier gain in standby mode
Photoamplifier input
Pin-out Diagrams
1
C1
2
3
C2
Package A
DETECT
16 TEST
C1
C2
1
2
3
4
5
6
7
8
15 HUSH
Strobed supply (VDD – 5 V) for photoamplifier low-side
reference
4
STROBE
14 VSS
DETECT
STROBE
VDD
13 TIMING RES
12 OSC CAP
11 LED
5
6
VDD
IRED
Positive supply voltage
IRED
Output to smoke chamber IR LED driver
Input-output to interconnected detectors
Output for driving piezoelectric horn
Complementary output for driving piezoelectric horn
Input for driving piezoelectric horn
Output to drive visible LED
10 FEEDBACK
I/O
7
I/O
9
HORN2
HORN1
8
HORN1
HORN2
FEEDBACK
LED
9
10
11
12
13
14
Package LW
16 TEST
C1
C2
1
2
3
4
5
6
7
8
OSC CAP
TIMING RES
VSS
Connection for capacitor to set clock frequency
Connection for resistor to set clock frequency
Negative supply voltage
15 HUSH
14 VSS
DETECT
STROBE
VDD
13 TIMING RES
12 OSC CAP
11 LED
Input for photoamplifier timer mode reference; can also
disable timer mode
IRED
15
16
HUSH
TEST
10 FEEDBACK
I/O
9
HORN2
HORN1
Enables push-to-test mode and diagnostic test/calibration
mode; starts timer mode, if enabled
Allegro MicroSystems, Inc.
115 Northeast Cutoff
2
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
Functional Block Diagram
I/O
+Supply
9 V
FEEDBACK
VDD
VDD
Band-gap
Reference
HORN2
HORN1
+
_
Low Battery
LED
VDD
Logic
Photoamp
DETECT
C1
+
_
Power-On
Reset
VDD
TIMING RES
OSC CAP
VSS
C2
STROBE
IRED
Oscillator
and Timing
VDD
–Supply
HUSH
TEST
Allegro MicroSystems, Inc.
115 Northeast Cutoff
3
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
DC ELECTRICAL CHARACTERISTICS at TA = –25°C to 75°C1. VSS = 0 V, in typical application (unless otherwise noted)
Characteristic
Symbol
Test Conditions
Test Pin
VDD
Min.
Typ.2
Max.
Units
Supply Voltage Range
VDD
5
–
6.0
–
12
V
Average in standby mode, configured per
typical application
5
5
5
12
12
12
–
–
–
–
–
–
9
ꢀA
mA
mA
During STROBE on, IRED off, configured per
typical application
Operating Supply Current
IDD
2.0
3.0
During STROBE on, IRED on, configured per
typical application
7
10
9
9
–
–
–
–
1.5
2.7
7.0
0.5
–
V
V
Low-Level Input Voltage
High-Level Input Voltage
VIL
16
9
–
–
V
15
9
–
–
V
7
9
3.2
6.3
8.5
1.6
–
–
V
10
9
–
–
V
VIH
16
9
–
–
V
15
9
–
–
V
VIN = VDD, STROBE active, OSC CAP = VDD
1, 2
3, 10, 12
1, 2, 3
10, 12
15, 16
16, 15
7
12
12
12
12
12
9
–
100
100
–100
–100
–1.0
10
nA
nA
nA
nA
ꢀA
ꢀA
ꢀA
ꢀA
V
Input Leakage High
Input Leakage Low
IIH
VIN = VDD
–
–
VIN = VST, STROBE active, OSC CAP = VDD
–
–
IIL
–
–
VIN = VSS
–
–
VIN = VDD
0.25
20
–
–
Input Pull-Down Current
IIN
No local smoke, VIN = VDD
No local smoke, VIN = 17 V
IO = 10 mA
9
–
80
7
12
6.5
6.5
6.5
6.5
–
140
0.6
1.0
–
11
–
–
Low-Level Output Voltage
High-Level Output Voltage
VOL
IO = 16 mA
8, 9
13
–
–
V
IO = 5 mA
–
0.5
–
V
VOH
IO = –16 mA
8, 9
5.5
–
V
VDD
– 0.1
Inactive, IO = –1 ꢀA
4
12
–
–
V
Strobe Output Voltage
VST
VDD
– 5.25
VDD
– 4.75
Active, IO = 100 to 500 ꢀA
Active, VDD = 6 to 12 V
VDD = 6 to 12 V
4
4
4
9
–
–
–
V
Line Regulation
ΔVST(ΔVDD)
–
–
–60
0.01
–
–
dB
Strobe Temperature
Coefficient
αST
%/°C
Inactive, IO = 1 ꢀA, TA = 25°C
6
6
12
9
–
–
0.1
V
V
IRED Output Voltage
VIRED
Active, IO = –6 mA, TA = 25°C
2.85
3.1
3.35
Continued on the next page…
Allegro MicroSystems, Inc.
115 Northeast Cutoff
4
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
DC ELECTRICAL CHARACTERISTICS (continued) at TA = –25°C to 75°C1, VSS = 0 V, in typical application (unless otherwise noted)
Characteristic
Line Regulation
Symbol
Test Conditions
Test Pin
VDD
Min.
–
Typ.2
–35
0.40
–
Max.
–
Units
dB
ΔVIRED(ΔVDD) Active, VDD = 6 to 12 V
6
IRED Temperature Coefficient
High-Level Output Current
OFF Leakage Current High
OFF Leakage Current Low
Low-Battery Alarm Threshold
αIRED
IOH
VDD = 6 to 12 V
6
7
–
9
–
–
%/°C
mA
ꢀA
VDD = Alarm, I/O active,VO = VDD – 2 V
–4.0
–
–
IOZ
VO = VDD
VO = VSS
11, 13
11, 13
5
12
12
–
–
1.0
–1.0
7.5
IOZ
–
–
ꢀA
VDD(th)
6.9
7.2
V
VDD
– 4
VDD
– 2
Common Mode Voltage
VIC
Any alarm condition
Any alarm condition
1, 2, 3
-
-
–
–
V
V
Smoke Comparator
Reference Voltage
VDD
– 3.7
VDD
– 3.3
VREF
Internal
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 at TA = –25°C to 75°C1. VSS = 0 V, in typical application (unless otherwise noted)
Characteristic
Oscillator Period
Symbol
tosc
Test Conditions
Test Pin
VDD
9
Min.
9.4
Typ.2
10.5
–
Max. Units
12
11
11
11.5
48
ms
s
tled1
No local or remote smoke
9
39
tled3
Local smoke
9
0.60
0.67
0.74
s
No
LED Pulse Period
LED Pulse Width
tled4
Remote smoke only
11
9
–
LED
Pulses
–
s
tled6
tled7
tw(led)
tst1
Pushbutton test, induced alarm
Timer mode, no alarm
11
11
11
4
9
9
9
9
9
0.60
9.67
9.5
0.67
10.8
–
0.74
11.8
11.5
11.9
2.96
s
s
ms
s
No local or remote smoke
After 1 of 3 valid samples
9.6
–
tst2
4
2.42
2.70
s
After 2 of 3 valid samples and during local
alarm
tst3
tst4
tst5
4
4
4
9
9
9
1.21
9.67
38.9
1.34
10.8
–
1.47
11.8
47.1
s
s
s
STROBE Pulse Period
STROBE Pulse Width
Remote smoke only
Chamber test or low battery test, no local
alarm
tst6
Pushbutton test, induced alarm
4
4
9
9
300
9.5
336
–
370
ms
ms
tw(st)
11.5
Continued on the next page…
Allegro MicroSystems, Inc.
115 Northeast Cutoff
5
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
AC ELECTRICAL CHARACTERISTICS (continued) at TA = –25°C to 75°C1, VSS = 0 V, in typical application (unless otherwise noted)
Characteristic
Symbol
Test Conditions
Test Pin
VDD
Min.
Typ.2
Max.
11.9
2.96
Units
tired1
No local or remote smoke
6
6
9
9.6
–
s
s
tired2
After 1 of 3 valid samples
9
2.42
2.70
After 2 of 3 valid samples and during local
alarm
tired3
6
9
1.21
1.34
1.47
s
IRED Pulse Period
tired4
tired5
Remote smoke only
6
6
6
6
6
6
7
9
9
9
9
9.67
38.9
300
94
–
10.8
–
11.8
47.1
370
116
30
s
s
Chamber test, no local alarm
Pushbutton test, induced alarm
tired6
336
–
ms
ꢀs
ꢀs
ꢀs
s
IRED Pulse Width
IRED Rise Time
IRED Fall Time
tw(ired)
tr(ired)
tf(ired)
td(io)
10% to 90%
90% to 10%
Local alarm
–
–
–
200
–
I/O to Active Delay
9
9
–
0
13 ×
tOSC
Rising Edge on I/O to Alarm
tr(io)
No local alarm
7
–
–
s
Horn Warning Pulse Period
Horn Warning Pulse Width
Horn On-Time
thorn
Low battery or degraded chamber sensitivity
Low battery or degraded chamber sensitivity
Local or remote alarm
8, 9
8, 9
8, 9
8, 9
9
9
9
9
38.9
9.5
–
–
–
47.1
11.5
–
s
tw(horn)
ton(horn)
toff(horn)
ms
ms
ms
252
84
Horn Off-Time
Local or remote alarm
–
–
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.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
6
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
Pin and Circuit Description
(In Typical Application)
As an input, the I/O is sampled every fourth clock cycle (nomi-
nally 42 ms). When the I/O pin is driven high by another device,
three consecutive samples with I/O high plus one additional
cycle (nominally 10.5 ms) are required to cause an alarm. If the
I/O falls below its threshold at any time during those (nomi-
nally) 95 ms, an internal latch is reset and there will not be an
alarm. Thus, depending on when during the (nominally) 42 ms
sample cycle I/O is initially forced high, the I/O must remain
high for a minimum of (nominally) 95 to 137 ms to cause an
alarm. This filtering provides significant immunity to I/O noise.
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.
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. This pin has an on-chip pull-down
device and must be left unconnected if not used. In the applica-
tion, 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.
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
LED 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.
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 Ω) 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):
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.
Condition
Standby
Pulse Occurrence
Every 43 s
I/O Pin
Local Smoke
Remote Alarm
Test Mode
Every 0.67 s
No pulses
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.
Every 0.67 s
Every 10 s
Timer Mode
Allegro MicroSystems, Inc.
115 Northeast Cutoff
7
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
OSC CAP (Oscillator Capacitor) Pin
the horn drivers and the I/O pin, and the LED blinks once every
0.67 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.
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-
terminal 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:
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 250 mV
below VSS. One option is to connect TEST to a –5 V supply
through a 12 kΩ resistor. In this mode, certain device pins are
reconfigured as described in table 1. The IRED pulse rate is
Thigh = 0.693 × RTIMINGRES × COSCCAP
.
VSS Pin
This pin is connected to the negative supply potential (usually
ground).
HUSH Pin
Table 1. Alternate Pin Configuration During Diagnostic
Test/Calibration Mode
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.
Pin Name
Alternate Configuration
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.
I/O
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 1. If this pin is high,
supervisory gain is selected and the amplifier output is
on pin C2.
HUSH
NOTE: If I/O is low, four rising edges on this pin will
cause the device to exit diagnostic/calibration mode and
enter an Allegro-defined test mode.
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).
FEED-
BACK
TEST Pin
This pin has an internal pull-down device and is used to manu-
ally invoke two test modes and timer mode.
This pin may be driven by an external clock source.
OSC CAP Driving this pin low and high drives the internal clock low
and high. The external RC network may remain intact.
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
336 ms (nominal). After the third IRED pulse (three consecu-
tive simulated smoke conditions), the successful test activates
This pin is reconfigured as the smoke integrator output.
Three consecutive smoke detections will cause this pin
HORN1
to go high and three consecutive no-smoke detections
cause this pin to go low.
This pin becomes a low-battery indicator. The open-drain
LED
NMOS output is normally off. If VDD falls below the low-
battery threshold, the output turns on.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
8
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
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.
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.
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.
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
During a local or a remote alarm condition, the horn output is a
continuous modulated tone, nominally: 252 ms on, 84 ms off.
The visible LED distinguishes a local alarm from a remote alarm.
During a local alarm, the LED blinks every 0.67 s (nominally),
but during a remote alarm, the LED is disabled and does not blink. condition is resolved when the battery is replaced.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
9
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
Timing Diagrams
(Not to Scale)
Standby Mode
tr(ired)
Test event
tf(ired)
OSC CAP Pin
90%
50%
10%
Internal Clock
tw(ired)
tosc
tst1, tired1
Photo Sample
tled1, tst5
Low-Battery Test
tst5, tired5
Chamber Test
tw(st)
STROBE Pin
IRED Pin
LED off (High-Z)
LED Pin
LED on
tw(led)
Low Battery Condition
VDD Pin
(Low battery)
Low-Battery Test
Failed “test period”
LED on
thorn
Horn Enable
LED Pin
tw(horn)
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
(Degraded chamber)
Chamber Test
Horn Enable
thorn
tw(horn)
LED off
(High-Z)
LED Pin
LED on
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
10
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
Local Smoke Detection Alarm Condition
1st strobe with smoke
3rd strobe with smoke
3rd strobe without smoke
IRED Pin
tst2,ired2
tw(st)
tst3,ired3
STROBE Pin
tw(led)
t
tst 3,ired3
led3
LED Pin
ton(horn)
toff(horn)
Horn Enable
I/O Pin
(Output)
Remote Alarm Condition
tw(st)
tst4,ired4
STROBE Pin
LED Pin
ton(horn)
toff(horn)
Horn Enable
tr(io)
I/O Pin
(Input)
Test Alarm Mode
STROBE Pin
tw(st)
tst6,ired6
LED Pin
tw(led)
tled6
TEST Pin
Horn Enable
I/O Pin
ton(horn)
toff(horn)
(Output)
Allegro MicroSystems, Inc.
115 Northeast Cutoff
11
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
Package A, 16-Pin DIP
+0.64
–0.38
19.05
+0.10
–0.05
0.25
16
+0.76
–0.25
6.35
7.62 BSC
10.92 MAX
A
1
2
Branded Face
Terminal #1 mark area
A
+1.65
–0.38
C
For Reference Only; not for tooling use (reference MS-001BB)
Dimensions in millimeters
SEATING
PLANE
5.33 MAX
3.30
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
+0.51
–0.38
0.38 MIN
3.30
2.54 BSC
0.13 MIN
+0.25
–0.38
1.52
16X 0.46±0.10
0.25 M
C
Package LW, 16-Pin SOICW
10.30 ±0.20
8°
0°
1.27
0.65
16
16
0.33
0.20
2.25
7.50 ±0.10 10.30 ±0.33
9.50
A
1.40 REF
1
2
1.27
0.40
1
2
0.25 BSC
PCB Layout Reference View
C
SEATING PLANE
GAUGE PLANE
16X
0.10
C
SEATING
PLANE
C
For Reference Only; not for tooling use (reference MS-013AA)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
1.27 BSC
2.65 MAX
0.51
0.31
0.30
0.10
Terminal #1 mark area
A
B
Branding scale and appearance at supplier discretion
C
Reference land pattern layout (reference IPC7351
SOIC127P1030X265-16M); all pads a minimum of 0.20 mm from all
adjacent pads; adjust as necessary to meet application process
requirements and PCB layout tolerances
Allegro MicroSystems, Inc.
115 Northeast Cutoff
12
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
Photoelectric Smoke Detector
with Interconnect and Timer
A5358
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 ©2009, 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 departures from the detail specifications as may be required to per-
mit improvements in the performance, 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 information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use;
nor for any infringement of patents or other rights of third parties which may result from its use.
For the latest version of this document, visit our website:
www.allegromicro.com
Allegro MicroSystems, Inc.
115 Northeast Cutoff
13
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
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