ALLEGRO A5358CA

PHOTOELECTRIC SMOKE DETECTOR
WITH INTERCONNECT AND TIMER
C1
1
16
TEST
C2
2
15
HUSH
DETECT
3
14
– SUPPLY
STROBE
4
13
TIMING RES.
+ SUPPLY
5
12
OSC. CAP.
IRED
6
11
LED
I/O
7
10
FEEDBACK
HORN 1
8
V SS
OSC. &
TIMING
V DD
LOGIC
HORN
DRIVER
9
HORN 2
The A5358CA 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 and British Standard BS 5446,
Part 1.
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 pushbutton test and during standby to periodically monitor the chamber
sensitivity.
Dwg. PC-007
The internal oscillator and timing circuitry keeps standby power to
a minimum by sensing for smoke every 10 seconds in a 10 µs window.
A special three-stage speedup sensing scheme is incorporated to
minimize the time to an audible alarm and also to reduce false triggering. Also, two consecutive cycles of degraded chamber sensitivity are
required for a warning signal to occur.
The A5358CA 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.
ABSOLUTE MAXIMUM RATINGS
(Voltages are referenced to VSS)
Supply Voltage Range,
VDD .................................... -0.5 V to +15 V
Input Voltage Range,
VIN ............................ -0.3 V to V DD + 0.3 V
Input Current, IIN ................................... 10 mA
Operating Temperature Range,
TA ..................................... -25 °C to +75°C
Storage Temperature Range,
TS ................................... -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.
FEATURES
■
■
■
■
■
■
■
■
Interconnect Up to 50 Detectors
Piezoelectric Horn Driver
All Internal Low-Battery Detection
Power-ON Reset
Internal Timer & Control for Reduced Sensitivity
Built-In Circuits to Reduce False Triggering
6 V to 12 V Operating Voltage Range
ESD-Protection Circuitry on All Pins
Always order by complete part number: A5358CA .
Data Sheet
26110.10A
5358
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
FUNCTIONAL BLOCK DIAGRAM
+ SUPPLY V DD
5
9V
I/O
7
BAND-GAP
REFERENCE
FEEDBACK
V DD
10
9
HORN 2
–
+
8
HORN 1
LOW BATTERY
LOGIC
11
PHOTO AMP
3
C1
1
C2
2
STROBE
4
POWER-ON
RESET
–
+
DETECT
TIMING RES.
+V
13
OSCILLATOR
& TIMING
V DD
IRED
+V
LED
12
OSC. CAP.
6
– SUPPLY
14
15
16
V SS
HUSH
TEST
Dwg. FC-006
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1995, 1996 Allegro MicroSystems, Inc.
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
DC ELECTRICAL CHARACTERISTICS at TA = -25°C to +75 °C*, VSS = 0 V, in typical application
(unless otherwise noted).
Characteristic
Symbol
Supply Voltage Range
VDD
Operating Supply Current
IDD
Test
Pin
VDD
Min.
5
–
6.0
–
12
V
Average Standby
Configured per Figure 1
5
12
–
–
12
µA
During Strobe ON, IRED OFF,
Configured per Figure 1
5
12
–
–
2.0
mA
During Strobe ON, IRED ON,
Configured per Figure 1
5
12
–
–
3.0
mA
Test Conditions
Limits
Typ.
Max.
Units
Low-Level Input Voltage
VIL
7
10
16
15
9
9
9
9
–
–
–
–
–
–
–
–
1.5
2.7
7.0
0.5
V
V
V
V
High-Level Input Voltage
VIH
7
10
16
15
9
9
9
9
3.2
6.3
8.5
1.6
–
–
–
–
–
–
–
–
V
V
V
V
Input Leakage High
IIH
1, 2
12
–
–
100
nA
3, 10, 12
12
–
–
100
nA
VIN = VST , Strobe Active,
Pin 12 @ VDD
1, 2, 3
12
–
–
-100
nA
VIN = VSS
10, 12
12
–
–
-100
nA
15, 16
12
–
–
-1.0
µA
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
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
8, 9
6.5
5.5
–
–
V
VIN = VDD, Strobe Active,
Pin 12 @ VDD
VIN = VDD
Input Leakage Low
Input Pull-Down Current
Low-Level Output Voltage
IIL
IIN
V OL
VIN = VDD
High-Level Output Voltage
VOH
IO= -16 mA
Strobe Output Voltage
VST
Inactive IO = -1 µA
4
12
VDD - 0.1
–
–
V
Active, IO = 100 µA to 500 µA
4
9
VDD - 5.25
–
VDD - 4.75
V
Continued...
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
DC ELECTRICAL CHARACTERISTICS, continued
Characteristic
Symbol
Line Regulation
∆VST(∆VDD)
Strobe Temperature Coeff.
IRED Output Voltage
Line Regulation
IRED Temperature Coefficient
α ST
VIRED
Test
Pin
VDD
Min.
Active, VDD = 6 V to 12 V
4
–
–
-60
–
dB
VDD = 6 V to 12 V
4
–
–
0.01
–
%/°C
Inactive IO = 1 µA, T A = +25°C
6
12
–
–
0.1
V
Active IO = -6 mA, TA = +25°C
6
9
2.85
3.1
3.35
V
–
-35
–
dB
Test Conditions
∆VIRED(∆VDD) Active, VDD = 6 V to 12 V
αIRED
6
Limits
Typ.
Max.
Units
VDD = 6 V to 12 V
6
–
–
+0.40
–
%/°C
7
9
-4.0
–
–
mA
High-Level Output Current
IOH
VDD = Alarm, I/O active,
VO = VDD - 2 V
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 VDD Alarm Threshold
V DD(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 Ref. Volt.
VREF
Any Alarm Condition
Internal
-
VDD - 3.7
–
VDD - 3.3
V
* Limits over the operating temperature range are based on characterization data.
Characteristics are production tested at +25°C only.
Typical values are at +25°C and are given for circuit design information only.
AC ELECTRICAL CHARACTERISTICS at TA = -25°C to +75 °C*, VSS = 0 V, in typical application
(unless otherwise noted).
Characteristic
Symbol
Test Conditions
Test
Pin
VDD
Min.
Limits
Typ.
Max.
12
9
9.4
10.5
11.5
ms
Units
Oscillator Period
tosc
Led Pulse Period
tled1
No Local or Remote Smoke
11
9
39
–
48
s
tled4
Remote Smoke Only
11
9
None
–
–
–
tled6
Local Smoke or Test
11
9
0.60
0.67
0.74
s
tled7
Timer Mode, No Alarm
11
9
9.67
10.8
11.8
s
11
9
9.5
–
11.5
ms
Led Pulse Width
tw(led)
Continued...
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
AC ELECTRICAL CHARACTERISTICS, continued.
Characteristic
Strobe Pulse Period
Symbol
Test Conditions
Test
Pin
VDD
Min.
Limits
Typ.
Max.
Units
tst1
No Local or Remote Smoke
4
9
9.6
–
11.9
s
tst2
After 1 of 3 Valid Samples
4
9
2.42
2.70
2.96
s
tst3
After 2 of 3 Valid Samples
and During Local Alarm
4
9
1.21
1.34
1.47
s
tst4
Remote Alarm
4
9
9.67
10.8
11.8
s
tst5
Chamber Test or Low Supply
Test, No Local Alarm
4
9
38.9
–
47.1
s
tst6
Pushbutton Test, No Alarm
4
9
300
336
370
ms
4
9
9.5
–
11.5
ms
Strobe Pulse Width
tw(st)
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
2.42
2.70
2.96
s
tired3
After 2 of 3 Valid Samples
and During Local Alarm
6
9
1.21
1.34
1.47
s
tired4
Remote Alarm
6
9
9.67
10.8
11.8
s
tired5
Chamber Test, No Local Alarm
6
9
38.9
–
47.1
s
tired6
Pushbutton Test, No Alarm
6
9
300
336
370
ms
6
9
94
–
116
µs
IRED Pulse Width
tw(ired)
IRED Rise Time
tr(ired)
10% to 90%
6
–
–
30
µs
IRED Fall Time
t f(ired)
90% to 10%
6
–
–
200
µs
I/O to Active Delay
td(io)
Local Alarm
7
9
–
0
–
s
Rising Edge on I/O to Alarm
tr(io)
No Local Alarm
7
9
–
–
1.34
s
Horn Warning Pulse Period
thorn
Low Supply and Degraded
Chamber Sensitivity
8, 9
9
38.9
–
47.1
s
Horn Warning Pulse Width
tw(horn)
Low Supply and Degraded
Chamber Sensitivity
8, 9
9
9.5
–
11.5
ms
Horn ON Time
ton(horn)
Local or Remote Alarm
8, 9
9
–
252
–
ms
Horn OFF Time
toff(horn)
Local or Remote Alarm
8, 9
9
–
84
–
ms
* Limits over the operating temperature range are based on characterization data.
Characteristics are production tested at +25°C only.
Typical values are at +25°C and are given for circuit design information only.
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
PIN AND CIRCUIT DESCRIPTION
(In Typical Application)
PIN 1 (C1)
A capacitor connected to this pin determines the gain
of the photo amplifier during the push-to-test mode and
during the chamber monitor test. A typical value for this
high-gain mode is 0.047 µF but should be selected
based on the photo chamber 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.
PIN 2 (C2)
A capacitor connected to this pin determines the gain
of the photo amplifier during standby. A typical value for
this low-gain mode is 4700 pF but should be selected
based on a specific photo chamber and the desired level
of sensitivity to smoke. Ae ≈ 1+(C2/10) where C2 is in pF.
Ae should not exceed 10 000. This gain increases by a
nominal 10% after a local alarm is detected (three consecutive detections). Coupling of other signals to C2
(C1 and the DETECT inputs also) must be minimized.
A resistor must be installed in series with C2.
PIN 3 (DETECT)
This is the input to the photo amplifier and is connected to the cathode of the photo diode. The photo
diode is operated at zero bias and should have low darkleakage current and low capacitance.
PIN 4 (STROBE)
This output provides a strobed, regulated voltage of
VDD – 5 V. The minus side of all internal and external
photo amplifier circuitry is referenced to this pin.
PIN 5 (VDD )
This pin is connected to the most-positive supply
potential and can range from 6 V to 12 V with respect
to VSS.
PIN 6 (IRED)
This output provides a pulsed base current for the
external npn transistor, which drives the IR emitter. Its
beta should be greater than 100. The IRED output is not
active, to minimize noise impact, when the horn and
visible LED outputs are active.
PIN 7 (I/O)
A connection at this pin allows multiple smoke detectors to be interconnected. If a local smoke condition
occurs, this pin is driven high. As an input, this pin is
sampled nominally every 1.35 seconds during standby.
Any local-alarm condition causes this pin to be ignored as
an input.
This pin has an on-chip pull-down resistor and must
be left unconnected if not used. In application, there is a
series current-limiting resistor to other smoke alarms.
PIN 8 (HORN1)
PIN 9 (HORN2)
PIN 10 (FEEDBACK)
These three pins are used in conjunction with external
passive components and a self-resonating piezoelectric
transducer. HORN1 is connected to the piezo metal
support electrode; the complementary output, HORN2, is
connected to the ceramic electrode and the FEEDBACK
input to the feedback electrode.
A continuous modulated tone indicates either a local
or remote alarm condition. A short (10 ms) chirp indicates
a low-battery condition or degraded chamber sensitivity.
The low-battery chirp occurs almost simultaneous with the
visible LED flash. If the FEEDBACK pin is not used, it
must be connected to VDD or VSS.
Continued...
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
PIN AND CIRCUIT DESCRIPTION, continued
PIN 11 (LED)
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. 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):
Standby
Local Smoke
Remote Alarm
Test Mode
Timer Mode
- Pulses every 43 seconds.
- Pulses every 0.67 second.
- No pulses.
- Pulses every 0.67 second.
- Pulses every 10 seconds.
PIN 12 (OSC. CAP.)
A capacitor between this pin and VDD , along with a
parallel resistor, forms part of a two-terminal oscillator and
sets the internal clock low time. With component values
as shown, this nominal time is 11 ms and essentially the
oscillator period.
cycle, IRED pulses every 336 ms (nominal) and amplifier
gain is increased by internal selection of C1. Background
reflections in the smoke chamber can be used to simulate
a smoke condition. After the third IRED pulse, a successful
test (three consecutive simulated smoke conditions)
activates the horn drivers and the I/O pin. When the
push-button 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 pin 16 also resets and starts the 10 minute hush timer
(timer mode).
Pin Name
Pin No. Configuration
I/O
7
Disabled as an output. A logic
high on this pin places the photo
amplifier output on pin 1 or pin 2
as determined by pin 15. The
amplifier output appears as
pulses.
HUSH
15
If the I/O pin is high, this pin
controls the amplifier gain capaci
tor. If pin 15 is low, normal gain is
selected and the amplifier output
is on pin 1. If pin 15 is high,
supervisory gain is selected and
the amplifier output is on pin 2.
PIN 13 (TIMING RES.)
A resistor between this pin and OSC. CAP. (pin 12) is
part of the two-terminal oscillator and sets the internal
clock high time, which is also the IRED pulse width. With
component values as shown, this nominal time is 105 µs.
PIN 14 (VSS)
This pin is connected to the most negative supply
potential (usually ground).
PIN 15 (HUSH)
This input pin serves two purposes in normal operation. It serves as an enable for the internal 10-minute
(nominal) timer and also as the reference for the smoke
comparator during the timer mode. This reference is
established by a resistive divider between VDD and
STROBE (RX1 and RX2). This allows the detector to have
a different sensitivity set point during the timer mode. If
the timer mode is not used, this pin can be left open or
connected to VSS, which disables this mode.
PIN 16 (TEST)
This pin has an internal pull-down device and is used
to manually invoke two test modes and a Timer Mode.
The Push-to-Test Mode is initiated by a high logic
level on this pin (usually the depression of a normally
open push-button switch to VDD). After one oscillator
FEEDBACK 10
If pin 7 is high and pin 15 is low
(normal gain), taking this pin to a
high logic level increases the
amplifier gain by ~10% (hysteresis).
OSC. CAP. 12
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.
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
PIN AND CIRCUIT DESCRIPTION, continued
The Diagnostic Test Mode is initiated by pulling this
pin below VSS and continuously sourcing 400 µA from the
pin for at least one clock cycle on the OSC. CAP. pin.
This mode is used to facilitate calibration and test of the IC
and the assembled detector. In this mode, certain device
pins are reconfigured as described below. In this mode,
the IRED pulse rate is increased to one every OSC. CAP.
cycle and the STROBE pin is always active. To exit this
mode, the test pin is floated for at least one OSC. CAP.
cycle.
Pin Name
Pin No. Configuration
HORN1
8
This pin is reconfigured as the
smoke integrator output. Three
consecutive smoke detections
will cause this pin to go high
and three consecutive nosmoke detections cause this
pin to go low.
LED
11
This pin becomes a low-battery
indicator. The open-drain
NMOS output is normally OFF.
If VDD falls below the lowbattery threshold, the output
turns ON.
TYPICAL APPLICATION
CONNECT FOR TIMER MODE OR "HUSH" OPERATION
15
+
200kΩ
SMOKE
CHAMBER
5
1kΩ
6
+
13
100kΩ
12
V DD
LOGIC
11
1000pF
100µF
22Ω
7
220Ω
220kΩ
10
HORN
DRIVER
9
100kΩ
8
TO/FROM
OTHER
UNITS
OSC. &
TIMING
4
14
10MΩ
VSS
3
9V
330Ω
2
22µF
16
1500pF
RX2
1
560Ω
4.7kΩ
C2
CONNECT FOR
NON-TIMER MODE
OPERATION
PUSH
TO
TEST
C1
5kΩ
RX1
8.2kΩ
VDD
Dwg. EC-006
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
STANDBY TIMING DIAGRAM
(not to scale)
OSC. CAP
(PIN 12)
t osc
INTERNAL
CLOCK
t ired
IRED
(PIN 6)
t w(ired)
STROBE
(PIN 4)
t w(st)
t st
t led
LED
(PIN 11)
t w(led)
SAMPLE
SMOKE
HORN
ENABLE
WARNING
CHIRP
t horn
t w(horn)
NO LOW SUPPLY
CHAMBER SENSITIVITY NORMAL
LOW SUPPLY OR
DEGRADED SENSITIVITY
WARNING CHIRPS ARE OFFSET
Dwg. WC-008
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
LOCAL ALARM TIMING DIAGRAM
(not to scale)
t w(ired)
90%
t f(ired)
10%
t ired3
10%
t ired4
t ired6
t st4
t st6
IRED
(PIN 6)
t st3
t w(st)
t w(led)
t led1
STROBE
(PIN 4)
t led6
LED
(PIN 11)
(NO PULSES)
I/O
(PIN 7)
(AS OUTPUT)
t on(horn)
(AS INPUT)
t off(horn)
t r(io)
(AS OUTPUT)
t on(horn)
t off(horn)
HORN
ENABLE
LOCAL SMOKE
(REMOTE SMOKE =
DON'T CARE)
NO SMOKE
REMOTE SMOKE
(NO LOCAL SMOKE)
TEST
3RD STROBE WITHOUT SMOKE
3RD STROBE WITH SMOKE
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Dwg. WC-009
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
Dimensions in Inches
(controlling dimensions)
0.014
0.008
9
16
0.430
MAX
0.280
0.240
0.300
BSC
1
0.070
0.045
0.100
0.775
0.735
8
0.005
BSC
MIN
0.210
MAX
0.015
0.150
0.115
MIN
0.022
0.014
Dwg. MA-001-16A in
Dimensions in Millimeters
(for reference only)
0.355
0.204
9
16
10.92
MAX
7.11
6.10
7.62
BSC
1
1.77
1.15
2.54
19.68
18.67
BSC
8
0.13
MIN
5.33
MAX
0.39
3.81
2.93
MIN
0.558
0.356
NOTES: 1. Lead thickness is measured at seating plane or below.
2. Lead spacing tolerance is non-cumulative.
3. Exact body and lead configuration at vendor’s option within limits shown.
Dwg. MA-001-16A mm
5358
PHOTOELECTRIC SMOKE DETECTOR
with INTERCONNECT and TIMER
SAFETY & SECURITY ICs
SELECTION GUIDE
Part
Number
A3054KU/SU
A5347CA
A5348CA
A5349CA
A5350CA
A5358CA
Function
Multiplexed Two-Wire Hall-Effect Sensor
Ionization-Type Smoke Detector with Interconnect and Timer
Ionization-Type Smoke Detector with Interconnect, Timer, and Reverse-Battery Protection
Ionization-Type Smoke Detector with Interconnect and Timer for AC Line Operation
Ionization-Type Smoke Detector with Interconnect and Reverse-Battery Protection
Photoelectric-Type Smoke Detector with Interconnect and Timer
Allegro MicroSystems, Inc. reserves the right to make, from time to time, such departures from
the detail specifications as may be required to permit improvements in the design of its products.
The information included herein is believed to be accurate and reliable. However, Allegro
MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or
other rights of third parties which may result from its use.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000