A5348CA [ALLEGRO]
SMOKE DETECTOR WITH INTERCONNECT AND TIMER; 烟雾探测器与互连和定时器
| 型号： | A5348CA |
| 厂家： | 
ALLEGRO MICROSYSTEMS |
| 描述： | SMOKE DETECTOR WITH INTERCONNECT AND TIMER |
| 文件： | 总8页 (文件大小：92K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
5348
SMOKE DETECTOR
WITH INTERCONNECT AND TIMER
The A5348CA is a low-current, CMOS circuit providing all of the
required features for an ionization-type smoke detector. A networking
capability allows as many as 125 units to be interconnected so that if
any unit senses smoke, all units will sound an alarm. In addition,
special features are incorporated to facilitate alignment and test of the
finished smoke detector. This device is designed to comply with
Underwriters Laboratories Specification UL217.
TIMER START
I / O
1
2
3
4
16
15
14
13
12
11
10
9
GUARD
2
DETECT. IN
LOGIC
LOW-V SET
TIMER OUT
LED
GUARD
1
SENSITIVITY
SET
OSC. &
TIMING
The internal oscillator and timing circuitry keeps standby power to
a minimum by powering down the device for 1.66 seconds and sensing
smoke for only 10 ms. Every 24 on/off cycles, a check is made for low
battery condition. By substituting other types of sensors, or a switch
for the ionization detector, this very-low power device can be used in
numerous other battery-operated safety/security applications.
5
6
OSC. CAP.
+ SUPPLY
V
HORN
2
DD
HORN
DRIVER
7
8
TIMING RES.
FEEDBACK
HORN
1
V
– SUPPLY
SS
Dwg. PC-004
The A5348CA is supplied in a low-cost, 16-pin dual in-line plastic
package. It is rated for continuous operation over the temperature
range of 0°C to +50°C.
FEATURES
■ Interconnect Up to 125 Detectors
■ Piezoelectric Horn Driver
■ Guard Outputs for Detector Input
■ Pulse Testing for Low Battery
ABSOLUTE MAXIMUM RATINGS
(Voltages are referenced to VSS)
■ Power-ON Reset
Supply Voltage Range,
■ Internal Reverse Battery Protection
■ Internal Timer & Control for Reduced Sensitivity
■ Built-In Hysteresis Reduces False Triggering
VDD ................................ -0.5 V to +15 V
Reverse Battery (10.5 V) ....................... 20 s
Input Voltage Range,
VIN ........................ -0.3 V to VDD + 0.3 V
Input Current, IIN ............................... 10 mA
Operating Temperature Range,
TA ..................................... 0°C to +50°C
Storage Temperature Range,
TS ............................... -55°C to +125°C
CAUTION: CMOS devices have input static protection
but are susceptible to damage when exposed to
extremely high static electrical charges.
Always order by complete part number: A5348CA .
5348
SMOKE DETECTOR
with INTERCONNECT
and TIMER
FUNCTIONAL BLOCK DIAGRAM AND TYPICAL APPLICATION
+ SUPPLY
V
I / O
2
DD
6
FEEDBACK
8
V
9 V
DD
+
11
HORN
2
10
–
+
HORN
1
3
LOW-V
SET
LOGIC
+V
5
LED
+
–
13
POWER-ON
RESET
SENSITIVITY
SET
TIMING RES.
7
+V
OSC. CAP.
12
OSCILLATOR
& TIMING
+
–
4
– SUPPLY
9
TIMER OUT
V
15
14
16
1
SS
DETECT.
IN
TIMER
START
GUARD
GUARD
1
2
+V
Dwg. FC-001B
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1990, 1995, Allegro MicroSystems, Inc.
5348
SMOKE DETECTOR
with INTERCONNECT
and TIMER
ELECTRICAL CHARACTERISTICS at TA = +25°C, VDD = 9.0 V, VSS = 0 V, C12 = 0.1 µF,
R7 = 8.2 MΩ (unless otherwise noted).
Limits
Test
Characteristic
Pin
Test Conditions
Operating
Min.
6.0
—
Typ.
9.0
—
Max.
12
Units
V
Supply Voltage Range
Detector Input Current
Input Offset Voltage
6
15
0 to 40% RH, VIN = 0 to 9.0 V
Active Guard
Active Guard
Detect Comparator
No Alarm to Alarm
Guard Amplifier
Smoke Comparator
to VSS
±1.0
±100
±100
±50
170
VDD - 0.5
VDD - 2.0
—
pA
mV
mV
mV
mV
V
14-15
16-15
15-13
13
—
—
—
—
—
—
Hysteresis
90
130
—
Common Mode Range
14-15
13-15
14
2.0
0.5
—
—
V
Active Guard Impedance
Oscillator Period
10
500
1.67
40
10
10
—
kΩ
kΩ
s
16
to VSS
—
—
12
No Alarm
1.34
32
2.00
48
Alarm
ms
ms
min
V
Oscillator Pulse Width
Timer Period
4
4
8.0
8.0
7.2
48.5
—
12
After Pin 1 High-to-Low, No Smoke
TA = 0 to 50°C
12
Low Voltage Threshold
Sensitivity Adj. Voltage
Horn Output Voltage
6
7.8
13
V13/VDD, pin 13 open circuit
IOUT = 16 mA, VDD = 9.0 V
IOUT = 16 mA, VDD = 7.2 V
IOUT = -16 mA, VDD = 9.0 V
IOUT = -16 mA, VDD = 7.2 V
Alarm
50
0.1
—
51.5
0.5
%
10-11
V
—
0.9
V
8.5
6.3
120
8.0
60
8.8
—
—
V
—
V
Horn Output ON Time
Horn Output OFF Time
Timer Start Logic Levels
Timer Start Input Current
10-11
10-11
1
160
10
80
40
—
208
12
ms
ms
ms
s
Low Battery
Alarm
104
48
Low Battery
32
VIH
3.5
—
—
V
VIL
—
1.5
V
1
VIN = 9.0 V
20
—
80
µA
Continued next page . . .
NOTE 1: Negative current is defined as coming out of (sourcing) the specified device pin.
NOTE 2: Alarm (Smoke) Condition is defined as V15 < V13; No Alarm (No Smoke) Condition as V15 > V13.
5348
SMOKE DETECTOR
with INTERCONNECT
and TIMER
ELECTRICAL CHARACTERISTICS continued
Limits
Typ.
Test
Characteristic
Pin
Test Conditions
VOUT = 0.5 V
Min.
500
10
Max.
—
Units
µA
Timer Out Output Current
LED Output ON Current
LED Output ON Time
LED Output OFF Time
4
—
—
10
40
5
VDD = 7.2 V, VOUT = 1.0 V
—
mA
ms
s
5
8.0
32
12
5
No Alarm, In Standby
48
No Alarm, Timer Mode After Pin 1
High-to-Low
8.0
25
10
—
12
60
—
s
µA
mA
V
I/O Current
2
No Alarm, VI/O = VDD - 2.0 V
Alarm, VI/O = VDD - 2.0 V
External “Alarm” In
-7.5
3.0
—
—
I/O Alarm Voltage
I/O Delay
2
2
6
—
—
“Alarm” Out
3.0
5.0
—
—
s
Supply Current
VDD = 9.0 V, No Alarm, No Loads
VDD = 12 V, No Alarm, No Loads
—
9.0
12
µA
µA
—
NOTE 1: Negative current is defined as coming out of (sourcing) the specified device pin.
NOTE 2: Alarm (Smoke) Condition is defined as V15 < V13; No Alarm (No Smoke) Condition as V15 > V13.
Detector Circuitry. When smoke is detected, the resistor divider
network that sets the sensitivity (smoke trip point) is altered to increase
the sensitivity set voltage (pin 13) by typically 130 mV with no exter-
nal connections to pins 3 or 13. This provides hysteresis and reduces
false triggering. An active guard is provided on both pins adjacent to
the detector input (pin 15). The voltage at pins 14 and 16 will be
within 100 mV of the input. This will keep surface leakage currents to
a minimum and provide a method of measuring the input voltage
without loading the ionization chamber. The active guard amplifier is
not power strobed and thus provides constant protection from surface
leakage currents. The detector input has internal diode protection
against static damage.
CIRCUIT DESCRIPTION
The A5348CA is a low-current CMOS circuit
providing all of the required features for an
ionization-type smoke detector.
Oscillator. An internal oscillator operates
with a period of 1.67 seconds during no-
smoke conditions. Every 1.67 seconds,
internal power is applied to the entire circuit
and a check is made for smoke. Every 24
clock cycles (40 seconds), the LED is pulsed
and a check is made for low battery by
comparing VDD to an internal reference.
Since very-low currents are used in the
device, the oscillator capacitor at pin 12
should be a low-leakage type (PTFE, polysty-
rene, or polypropylene).
Alarm Circuitry. If smoke is detected, the oscillator period changes
to 40 ms and the horn is enabled. The horn output is typically 160 ms
ON, 80 ms OFF. During the OFF time, smoke is again checked and
will inhibit further alarm output if smoke is not sensed. During smoke
conditions the low battery alarm is inhibited and the LED is driven at a
1 Hz rate.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
5348
SMOKE DETECTOR
with INTERCONNECT
and TIMER
Sensitivity Adjust. The detector sensitiv-
ity to smoke is set internally by a voltage
divider connected between VDD and VSS. The
sensitivity can be externally adjusted to the
individual characteristics of the ionization
chamber by connecting a resistor between pin
13 and VDD, or between pin 13 and VSS.
TYPICAL APPLICATION
200 kΩ
9 V
TIMER
MODE
Low Battery. The low battery threshold is
set internally by a voltage divider connected
between VDD and VSS. The threshold can be
increased by connecting a resistor between
pin 3 and VDD. The threshold can be de-
creased by connecting a resistor between pin
3 and VSS. The battery voltage level is
checked every 40 seconds during the 10 mA,
10 ms LED pulse. If an LED is not used, it
should be replaced with an equivalent resistor
(typically 500 Ω to 1000 Ω) such that the
battery loading remains at 10 mA.
PUSH
TO
TEST
TO
OTHER
UNITS
16
1
2
3
4
200 Ω
15
14
13
12
11
10
9
LOGIC
NOTE
3
NOTE
1
OSC. &
TIMING
330 Ω
5
6
0.1 µF
V
DD
HORN
DRIVER
8.2 MΩ
7
8
1 µF
V
SS
Timer. An internal timer is provided that
can be used in various configurations to allow
for a period of reduced smoke detector
sensitivity (“hush”). When a high-to-low
transition occurs at pin 1, the internal timer is
reset, the timer mode enabled, and the circuit
reset to a no alarm condition. The LED will
flash at a 10 second rate. If the level of
smoke is increased such that the reduced
sensitivity level is reached, the device will go
into the alarm condition. The timer, how-
ever, will continue to completion of the
nominal 10-1/4 minute period (368 clock
cycles). If the timer mode is not used, pin 1
should be tied low.
0.001 µF
NOTE 2
Dwg. EC-005A
NOTE 1:Use an external resistor to adjust sensitivity for a particular
smoke chamber.
NOTE 2:Select resistor to reduce sensitivity during timer mode.
NOTE 3:A resistor to ground or VDD may be added to this pin to modify
low battery voltage threshold.
I/O. A connection is provided at pin 2 to
allow multiple smoke detectors to be
commoned. If any single unit detects smoke
(I/O is driven high), all connected units will
sound their associated horns after a nominal 3
second delay. The LED is suppressed when
an alarm is signaled from an interconnected
unit.
Testing. On power up, all internal counters are reset. Internal test
circuitry allows for low battery check by holding pins 8 and 12 low
during power up, then reducing VDD and monitoring HORN1 (pin 10).
All functional tests can be accelerated by driving pin 12 with a 2 kHz
square wave. The 10 ms strobe period must be maintained for proper
operation of the comparator circuitry.
5348
SMOKE DETECTOR
with INTERCONNECT
and TIMER
TIMING DIAGRAMS IN TYPICAL APPLICATION
NON-TIMER MODE
NO ALARM
NO LOW BATTERY
STANDBY MODE
ALARM
NO LOW BATTERY
ALARM AND
LOW BATTERY
NO ALARM
LOW BATTERY
V12
OSC. CAP
10 ms
1.67 s
40 ms
INTERNAL
CLOCK
30 CLOCK CYCLES
24 CLOCK CYCLES
24 CLOCK CYCLES
LED
LED OFF
LED
ON
12 CLOCK CYCLES
6 CLOCK CYCLES
6 CLOCK CYCLES
SMOKE
COMPARATOR
SAMPLE
LOW BATTERY
WARNING
HORN
ON
HORN
OFF
V15 < V13 (SMOKE)
SMOKE
CHAMBER
V15 > V13 (NO SMOKE)
Dwg. WC-003
TIMER MODE
V12
OSC. CAP
10 ms
1.67 s
INTERNAL
CLOCK
368 CLOCK CYCLES
TIMER
START
TIMER
OUT
OUTPUTS OFF (HIGH Z)
6 CLOCK CYCLES
LED
END OF TIMER
NOTIFICATION
LED
ON
HORN
Dwg. WC-005
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
5348
SMOKE DETECTOR
with INTERCONNECT
and TIMER
I/O OPERATION
REMOTE ALARM MODE
1.67 s
40 ms
INTERNAL
CLOCK
4 CYCLES
2 CYCLES
HORN
ON
OFF
HORN
HORN NOT SELF COMPLETING
WHEN IN REMOTE ONLY ALARM
V2 IN
I/O
LOCAL ALARM MODE
INTERNAL
CLOCK
HORN
ON
OFF
HORN
72 CLOCK CYCLES
V2 OUT
I/O
Dwg. WC-004
5348
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
8
0.100
0.070
0.045
0.005
BSC
MIN
0.775
0.735
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
8
2.54
0.13
BSC
MIN
19.68
18.67
5.33
MAX
0.39
3.81
2.93
MIN
0.558
0.356
Dwg. MA-001-16A mm
NOTES: 1. Lead thickness is measured at seating plane or
below.
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.
2. Lead spacing tolerance is non-cumulative.
3. Exact body and lead configuration at vendor’s
option within limits shown.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
相关型号：
A5348CA-T
The A5348 is a low-current, BiCMOS circuit providing all of the required features for an ionization-type smoke detector.
ALLEGRO
A5358
The A5358 is a low-current BiCMOS circuit providing all of the required features for a photoelectric type smoke detector.
ALLEGRO
A5358CA-T
The A5358 is a low-current BiCMOS circuit providing all of the required features for a photoelectric type smoke detector.
ALLEGRO
A5358CLWTR-T
The A5358 is a low-current BiCMOS circuit providing all of the required features for a photoelectric type smoke detector.
ALLEGRO
©2020 ICPDF网 联系我们和版权申明