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5355
SMOKE DETECTOR WITH INTERCONNECT
NO CONNECT. I/O LOW-V SET NO CONNECT. LED + SUPPLY TIMING RES. FEEDBACK 1 2 3 4 5 6 7 8 V SS V DD NC NC LOGIC 16 15 14 13 12 11 10 9 GUARD 2 DETECT. IN GUARD 1 SENSITIVITY SET OSC. CAP. HORN 2 HORN 1 - SUPPLY
Data Sheet 26110.5A
The A5355CA 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. 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. The A5355CA is supplied in a low-cost, 16-pin dual in-line plastic package. It is rated for continuous operation over the temperature range of 0C to +50C.
OSC. & TIMING
HORN DRIVER
Dwg. PC-004-1
FEATURES
s s s s s s Interconnect Up to 125 Detectors Piezoelectric Horn Driver Guard Outputs for Detector Input Pulse Testing for Low Battery Power-ON Reset Internal Reverse Battery Protection
ABSOLUTE MAXIMUM RATINGS
(Voltages are referenced to V SS)
Supply Voltage Range, 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 ..................................... 0C to +50C Storage Temperature Range, TS ............................... -55C to +125C
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: A5355CA .
5355 SMOKE DETECTOR with INTERCONNECT
FUNCTIONAL BLOCK DIAGRAM AND TYPICAL APPLICATION
+ SUPPLY V DD 6 9V I/O 2 V DD FEEDBACK 8 11 HORN 2
+
3 LOW-V SET
- +
LOGIC
10 HORN 1 5 LED +V
13 SENSITIVITY SET
- +
POWER-ON RESET
TIMING RES. 7 OSCILLATOR & TIMING OSC. CAP. 12 +V
- SUPPLY 9 V SS 14 GUARD 1 +V DETECT. 15 IN 16 GUARD 2 1 NO CONNECTION 4 NO CONNECTION
- +
Dwg. FC-001-3
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright (c) 1996, Allegro MicroSystems, Inc.
5355 SMOKE DETECTOR WITH INTERCONNECT
ELECTRICAL CHARACTERISTICS at TA = +25C, VDD = 9.0 V, VSS = 0 V, C12 = 0.1 F, R7 = 8.2 M (unless otherwise noted).
Characteristic Supply Voltage Range Detector Input Current Input Offset Voltage Test Pin 6 15 14-15 16-15 15-13 Common Mode Range 14-15 13-15 Active Guard Impedance 14 16 Oscillator Period 12 Limits Test Conditions Operating 0 to 40% RH, VIN = 0 to 9.0 V Active Guard Active Guard Detect Comparator Guard Amplifier Smoke Comparator to V SS to VSS No Alarm Alarm Oscillator Pulse Width Low Voltage Threshold Horn Output Voltage 4 6 10-11 TA = 0 to 50C IOUT = 16 mA, VDD = 9.0 V IOUT = 16 mA, VDD = 7.2 V IOUT = -16 mA, V DD = 9.0 V IOUT = -16 mA, V DD = 7.2 V Horn Output ON Time 10-11 Alarm Low Battery Horn Output OFF Time 10-11 Alarm Low Battery LED Output ON Current LED Output ON Time LED Output OFF Time I/O Current 5 5 5 2 No Alarm, In Standby No Alarm, VI/O = VDD - 2.0 V Alarm, VI/O = V DD - 2.0 V I/O Alarm Voltage I/O Delay Supply Current 2 2 6 External "Alarm" In "Alarm" Out VDD = 9.0 V, No Alarm, No Loads VDD = 12 V, No Alarm, No Loads
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 .
Min. 6.0 -- -- -- -- 2.0 0.5 -- -- 1.34 32 8.0 7.2 -- -- 8.5 6.3 120 8.0 60 32 10 8.0 32 25 -7.5 3.0 -- -- --
Typ. 9.0 -- -- -- -- -- -- 10 500 1.67 40 10 -- 0.1 -- 8.8 -- 160 10 80 40 -- 10 40 -- -- -- 3.0 5.0 --
Max. 12 1.0 100 100 50 VDD - 0.5 VDD - 2.0 -- -- 2.00 48 12 7.8 0.5 0.9 -- -- 208 12 104 48 -- 12 48 60 -- -- -- 9.0 12
Units V pA mV mV mV V V k k s ms ms V V V V V ms ms ms s mA ms s A mA V s A A
VDD = 7.2 V, VOUT = 1.0 V
5355 SMOKE DETECTOR with INTERCONNECT
CIRCUIT DESCRIPTION
The A5355CA 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, polystyrene, or polypropylene). Detector Circuitry. 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. 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. Sensitivity Adjust. The detector sensitivity must be externally adjusted to the individual characteristics of the ionization chamber by connecting resistors between pin 13 and VDD, and between pin 13 and VSS. 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 decreased 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 to 1000 ) such that the battery loading remains at 10 mA. 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 HORN 1 (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.
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
5355 SMOKE DETECTOR WITH INTERCONNECT
TYPICAL APPLICATION
9V
200 k
TO OTHER UNITS 1 200 2 NOTE 2 330 5 6 8.2 M 7 1 F 8 V SS V DD 3 4 NC NC LOGIC 16 15 14 OSC. & TIMING 13 NOTE 1 12 11 10 0.1 F PUSH TO TEST
200 k
HORN DRIVER
1 M
9
330 k
0.001 F
Dwg. EC-005-5
NOTE 1: An external resistor divider is used to adjust sensitivity for the particular smoke chamber. NOTE 2: A resistor to ground or VDD may be added to this pin to modify low battery voltage threshold.
TIMING DIAGRAMS IN TYPICAL APPLICATION
NO ALARM NO LOW BATTERY STANDBY MODE ALARM NO LOW BATTERY ALARM AND LOW BATTERY NO ALARM LOW BATTERY
V12 OSC. CAP
1.67 s
10 ms
40 ms
INTERNAL CLOCK
4.7 M
30 CLOCK CYCLES 6 CLOCK CYCLES
24 CLOCK CYCLES
24 CLOCK CYCLES
LED
LED OFF
LED ON
12 CLOCK CYCLES
6 CLOCK CYCLES
SMOKE COMPARATOR
SAMPLE
4.7 M
LOW BATTERY WARNING HORN ON OFF
HORN
SMOKE CHAMBER
V15 > V13 (SMOKE) V15 < V13 (NO SMOKE)
Dwg. WC-003-1
5355 SMOKE DETECTOR with INTERCONNECT
I/O OPERATION
REMOTE ALARM MODE 40 ms 1.67 s
INTERNAL CLOCK
4 CYCLES
2 CYCLES
HORN
HORN ON
OFF
V2 IN I/O
HORN NOT SELF COMPLETING WHEN IN REMOTE ONLY ALARM
LOCAL ALARM MODE
INTERNAL CLOCK
HORN
HORN ON
OFF
72 CLOCK CYCLES
V2 OUT I/O
Dwg. WC-004
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
5355 SMOKE DETECTOR WITH INTERCONNECT
Dimensions in Inches (controlling dimensions)
0.014 0.008
16
9
0.430 0.280 0.240
MAX
0.300
BSC
1 0.070 0.045
0.100 0.775 0.735
BSC
8 0.005
MIN
0.210
MAX
0.015
MIN
0.150 0.115 0.022 0.014
Dwg. MA-001-16A in
Dimensions in Millimeters (for reference only)
0.355 0.204
16
9
10.92 7.11 6.10
MAX
7.62
BSC
1 1.77 1.15
2.54 19.68 18.67
BSC
8 0.13
MIN
5.33
MAX
0.39
MIN
3.81 2.93 0.558 0.356
Dwg. MA-001-16A mm
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.
5355 SMOKE DETECTOR with INTERCONNECT
SAFETY & SECURITY ICs SELECTION GUIDE
Part Number A3054KU/SU A5347CA A5348CA A5349CA A5354CA A5355CA 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 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

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