Document
5358
PHOTOELECTRIC SMOKE DETECTOR WITH INTERCONNECT AND TIMER
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. 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.
Data Sheet 26110.10A
C1 C2 DETECT STROBE + SUPPLY IRED I/O HORN 1
1 2 3 4 5 6 7 8 HORN DRIVER V DD LOGIC OSC. & TIMING V SS
16 15 14 13 12 11 10 9
TEST HUSH – SUPPLY TIMING RES. OSC. CAP. LED FEEDBACK HORN 2
Dwg. PC-007
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
s s s s s s s s 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 .
5358 PHOTOELECTRIC SMOKE DETECTOR with INTERCONNECT and TIMER
FUNCTIONAL BLOCK DIAGRAM
+ SUPPLY V DD 5 9V BAND-GAP REFERENCE
I/O 7 V DD FEEDBACK 10 9 HORN 2 8 HORN 1 LOGIC PHOTO AMP +V
LOW BATTERY
C1
1 TIMING RES. +V
C2
2 4 V DD 6 OSCILLATOR & TIMING
STROBE IRED
– SUPPLY 14 V SS 15 HUSH 16 TEST
Dwg. FC-006
– +
DETECT
3
– +
POWER-ON RESET
11 LED
13
12 OSC. CAP.
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 Supply Voltage Range Operating Supply Current Symbol VDD IDD Average Standby Configured per Figure 1 During Strobe ON, IRED OFF, Configured per Figure 1 During Strobe ON, IRED ON, Configured per Figure 1 Low-Level Input Voltage VIL Test Conditions Test Pin 5 5 VDD – 12 Min. 6.0 – Limits Typ. Max. – – 12 12 Units V µA mA
5
12
–
–
2.0
5
12
–
–
3.0
mA
7 10 16 15 7 10 16 15 VIN = VDD, Strobe Active, Pin 12 @ VDD VIN = VDD 1, 2
9 9 9 9 9 9 9 9 12
– – – – 3.2 6.3 8.5 1.6 –
– – – – – – – – –
1.5 2.7 7.0 0.5 – – – – 100
V V V V V V V V nA
High-Level Input Voltage
VIH
Input Leakage High
IIH
3, 10, 12 1, 2, 3
12 12
– –
– –
100 -100
nA nA
Input Leakage Low
IIL
VIN = VST , Strobe Active, Pin 12 @ VDD VIN = VSS
10, 12 15, 16
12 12 9 9 12 6.5 6.5 6.5 6.5 12 9
– – 0.25 20 – – – – 5.5 VDD - 0.1 VDD - 5.25
– – – – – – – 0.5 – – –
-100 -1.0 10 80 140 0.6 1.0 – – – VDD - 4.75
nA µA µA µA µA V V V V V V
Input Pull-Down Current
IIN
VIN = VDD No Local Smoke, VIN = VDD No Local Smoke, VIN = 17 V
16, 15 7 7 11 8, 9 13 8, 9 4 4
Low-Level Output Voltage
V OL
IO = 10 mA IO = 16 mA IO = 5 mA
High-Level Output Voltage Strobe Output Voltage
VOH VST
IO= -16 mA Inactive IO = -1 µ A Active, IO = 100 µ A to 500 µ A
Continued...
5358 PHOTOELECTRIC SMOKE DETECTOR with INTERCONNECT and TIMER
DC ELECTRICAL CHARACTERISTICS, continued
Test Pin 4 4 6 6 6 6 7 – 9 Limits Typ. Max. -60 0.01 – 3.1 -35 +0.40 – – – 0.1 3.35 – – –
Characteristic Line Regulation Strobe Temperature Coeff. IRED Output Voltage
Symbol ∆VST(∆VDD) α ST.