A5364CA

A5364 Ionization Smoke Detector with Interconnect Features and Benefits Description ▪ Low average standby current for long battery life ▪ Interconnect up to 125 detectors ▪ Piezoelectric horn driver ▪ Guard outputs for detector input ▪ Pulse testing for low battery ▪ Power-on reset (POR) ▪ Internal reverse battery protection ▪ Built-in hysteresis reduces false triggering ▪ Temporal horn pattern, per UL217, NFPA72, and ISO8201 ▪ UL Recognized for UL217 applications, per file # S2113 The A5364 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 their alarm. In addition, special features are incorporated to facilitate alignment and test of the finished smoke detector. The device is Recognized by Underwriters Laboratories for use in smoke alarms that comply with Standard UL217. Package: 16-pin DIP (suffix A) The internal oscillator and timing circuitry keep standby power to a minimum by powering down the device for 1.66 seconds and sensing for smoke for only 10 ms. Every 24 on-off cycles, a check is made for a 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. Not to scale The A5364 is supplied in a low-cost 16-pin dual in-line plastic package (DIP). It is rated for continuous operation over the temperature range of 0°C to 50°C. The Pb (lead) free version (suffix –T) has 100% matte tin leadframe plating. Typical Application 200 kΩ GUARD2 1 NC 200 Ω To / from other units B 2 3 DETECT IN I/O A5364 LOW-V SET 4 NC 330 Ω 9V 5 6 8.2 MΩ 1 μF 7 8 LED GUARD1 SENSITIVITY SET OSC CAP VDD HORN2 TIMING RES HORN1 FEEDBACK VSS 16 200 k Ω 15 Push to Test 14 13 B A resistor to VSS or VDD may be added to this pin to modify low battery voltage threshold. C Value of component will vary, based on the piezoelectric horn used. A 12 0.1 μF 11 10 9 1.5 MΩ C 220 kΩ C 26110.7E A Use an external resistor to adjust sensitivity for a particular smoke chamber. 0.001 μF C Ionization Smoke Detector with Interconnect A5364 Selection Guide Part Number Pb-Free A5364CA-T Packing Yes A5364CA 25 pieces per tube – Absolute Maximum Ratings* Characteristic Symbol Supply Voltage Range Input Voltage Range Reverse Battery Condition Duration Operating Ambient Temperature Junction Temperature Storage Temperature Range Rating Units VDD Referenced to VSS –0.5 to 15 V VIN Referenced to VSS –0.3 to VDD+ 0.3 V 20 s IIN 10 mA tRBAT Input Current Notes 10.5 V TA 0 to 50 ºC TJ(max) 150 ºC Tstg –55 to 125 ºC * CAUTION: CMOS devices have input static protection but are susceptible to damage when exposed to extremely high static electrical charges. THERMAL CHARACTERISTICS Characteristic Symbol Package Thermal Resistance RθJA Test Conditions* Value Units 4-layer PCB based on JEDEC standard 38 ºC/W *Additional thermal information available on Allegro website. Terminal List Table Number Pin-out Diagram NC 1 16 GUARD2 I/O 2 15 DETECT IN LOW-V SET 3 NC 4 14 GUARD1 13 SENSITIVITY SET 1 Name NC Function 2 I/O 3 LOW-V SET 4 NC No connection 5 LED Output to drive visible LED 6 VDD Positive supply voltage 7 TIMING RES FEEDBACK No connection Input/output to interconnected detectors Optionally used with a resistor to adjust low-battery threshold Terminal for timing resistor, sets internal bias (affects timing) Input for driving piezoelectric horn LED 5 12 OSC CAP 8 VDD 6 11 HORN2 9 10 HORN1 VSS TIMING RES 7 10 HORN1 Output for driving piezoelectric horn 11 HORN2 Complementary output for driving piezoelectric horn 12 OSC CAP 13 SENSITIVITY SET 14 GUARD1 15 DETECT IN 16 GUARD2 FEEDBACK 8 9 VSS Negative supply voltage Terminal for charging/discharging an external capacitor to run the oscillator Optionally used with a resistor to adjust sensitivity for a specific chamber Active guard 1 for detector input Input from detector chamber Active guard 2 for detector input Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com Copyright © 2001, 2002 Allegro MicroSystems, Inc. 2 Ionization Smoke Detector with Interconnect A5364 Functional Block Diagram I/O +Supply 9V VDD FEEDBACK VDD Band Gap LBSamp HORN2 HORN1 Low Battery Sample Low Battery Comparator 600 kΩ _ LED Logic LOW-V SET + VDD + 500 kΩ Power-on Reset + _ SENSITIVITY SET SSamp Smoke Comparator Smoke Sample 1.1 MΩ TIMING RES LBSamp SSamp Oscillator and Timing + VDD OSC CAP -Supply VSS + _ GUARD1 DETECT IN GUARD2 + VDD ION CHAMBER Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3 Ionization Smoke Detector with Interconnect A5364 ELECTRICAL CHARACTERISTICS1,2 at TA = 25°C, VDD = 9.0 V, VSS = 0 V, COSCCAP = 0.1 μF, RTIMINGRES = 8.2 MΩ (unless otherwise noted) Characteristic Supply Voltage Range Supply Current Detector Input Current Symbol VDD IDD Oscillator Pulse Width IDETECTIN VOS(GUARD1) VOS(GUARD2) VOS VHYS VCM(guard) VCM ZAG1 ZAG2 tosc tosc(alarm) tw(osc) Low-Battery Threshold VDD(th) Input Offset Voltage Hysteresis Common Mode Range Active Guard Impedance Oscillator Period Sensitivity Adjust Voltage VSET VOL Horn Output Voltage VOH Horn Output On-Time ton(horn) tw(horn) toff1(horn) Horn Output Off-Time LED Output-On Current LED Output On-Time LED Output Off-Time toff2(horn) thorn ILED tw(LED) tLED1 tLED3 tLED4 Test Conditions Operating VDD = 9.0 V, no alarm, no loads VDD = 12 V, no alarm, no loads 0% to 40% RH, VIN = 0 to 9.0 V Active GUARD1 Active GUARD2 Detect comparator No alarm to alarm Guard amplifier Smoke comparator GUARD1 to VSS GUARD2 to VSS No alarm Local or remote alarm TA = 0°C to 50°C, LOW-V SET open circuit VSENSITIVITYSET / VDD, SENSITIVITY SET 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 Local or remote alarm Low battery Local or remote alarm (see Timing Diagrams section) Local or remote alarm (see Timing Diagrams section) Low battery VDD = 7.2 V, VLED = 1.0 V No alarm, in standby Local alarm or test alarm Remote alarm, no local smoke Test Pin 6 6 6 15 14, 15 16, 15 15, 13 13 14, 15 13, 15 14 16 12 12 12 Min. 6.0 — — — — — — 90 2.0 0.5 — — 1.34 32 8.0 Typ. 9.0 5.0 — — — — — 130 — — 10 500 1.67 40 10 Max. 12 9.0 12 ±1.0 ±100 ±100 ±50 170 VDD – 0.5 VDD – 2.0 — — 2.00 48 12 Units V μA μA pA mV mV mV mV V V kΩ kΩ s ms ms 6 7.2 — 7.8 V 13 48.5 50 51.5 %VDD 10, 11 10, 11 10, 11 10, 11 10,11 10, 11 — — 8.5 6.3 450 8.0 0.1 — 8.8 — 500 10 0.5 0.9 — — 550 12 V V V V ms ms 10, 11 450 500 550 ms 10, 11 1350 1500 1650 ms 10, 11 5 5 5 5 32 10 8.0 32 0.76 48 — 12 48 1.14 s mA ms s s 5 — 40 — 10 40 0.97 No LED pulses — s Continued on the next page… Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 4 Ionization Smoke Detector with Interconnect A5364 ELECTRICAL CHARACTERISTICS1,2 (continued) at TA = 25°C, VDD = 9.0 V, VSS = 0 V, COSCCAP = 0.1 μF, RTIMINGRES = 8.2 MΩ (unless otherwise noted) Characteristic Symbol Test Conditions Test Pin Min. Typ. Max. Units No alarm, VI/O = VDD – 2.0 V 2 25 — 60 μA IIOL I/O Current Local alarm, VI/O = VDD – 2.0 V 2 –7.5 — — mA IIOH I/O Alarm Voltage VIH(IO) External “alarm” in 2 3.0 — — V I/O Delay tr(io) Local or test alarm to I/O active 2 — 3.0 — s 1Negative current is defined as coming out of the specified device pin (sourcing). 2Alarm (smoke) condition is defined as V DETECTIN < VSENSITIVITYSET; no alarm (no smoke) condition is defined as VDETECTIN > VSENSITIVITYSET. Circuit Description The A5364 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 for 10 ms and a check is made for smoke. Every 24 clock cycles (approximately 40 seconds), the LED pin is pulsed and a check is made for low battery by comparing VDD to an internal reference. Because very-low currents are used in the device, the oscillator capacitor at the OSC CAP pin should be a low-leakage type (PTFE, polystyrene, or polypropylene). Detector Circuitry When the voltage on the DETECT IN pin is less than the voltage on the SENSITIVITY SET pin, the A5364 evaluates this as a smoke condition. During a smoke condition, the resistor divider network that sets the sensitivity (also referred to as the smoke trip point) is altered to increase VSENSITIVITYSET by 130 mV typical (with no external connections on the SENSITIVITY SET pin). This provides hysteresis and reduces false triggering. An active guard is provided on GUARD1 and GUARD2, the two pins adjacent to the detector input, the DETECT IN pin. VGUARD1 and VGUARD2 will be within 100 mV of VDETECTIN. 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 electrostatic damage. Alarm Circuitry If smoke is detected, the oscillator period changes to 40 ms and the horn is enabled. The horn output follows a temporal horn pattern of nominally: 0.5 s on, 0.5 s off, 0.5 s on, 0.5 s, 0.5 s on, 1.5 s off. During the off-time, smoke is checked and further alarm output will be inhibited if smoke is not sensed. During a smoke condition, the low-battery alarm is inhibited and the LED is pulsed approximately once every second. Sensitivity Adjust The detector sensitivity to smoke is set internally by a voltage divider connected between VDD and VSS. The sensitivity can, however, be externally adjusted to the individual characteristics Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 5 Ionization Smoke Detector with Interconnect A5364 of the ionization chamber by connecting a resistor between the SENSITIVITY SET pin and either the VDD or VSS pins. nally 7.5 V), and a target threshold, V(th)set , the resistor should have the value: With no external connections on the SENSITIVITY SET pin, while the A5364 is checking for smoke: VSENSITIVITYSET = VDD / 2 . To increase sensitivity, a resistor can be connected between SENSITIVITY SET and VDD, with the value: RSENSITIVITYSET = 1.1E6 × K / (1 – K) , where K = VDD / VSENSITIVITYSET – 1 . To decrease sensitivity, a resistor can be connected between SENSITIVITY SET and VSS, with the value: RSENSITIVITYSET = 1.1E6 × K / (1 – K) , where K = 1 / (VDD / VSENSITIVITYSET – 1) . Low Battery The low battery condition threshold is set internally by a voltage divider connected between VDD and VSS. The threshold can be externally adjusted by connecting a resistor between the LOW-V SET pin and either the VDD or VSS pins. To increase the threshold, a resistor can be connected between LOW-V SET and VSS. Given an initial threshold, V(th)init (nominally 7.5 V), and a target threshold, V(th)set , the resistor should have the value: RLOWVSET = 600E3 × K / (1 – 0.375 × K) , where K = 1 / (V(th)set / [0.727 × V(th)init] – 1) . To decrease the threshold, a resistor can be connected between LOW-V SET and VDD. Given an initial threshold, V(th)init (nomi- RLOWVSET = 960E3 × K / (0.6 – 1.6 × K) , where K = V(th)set / (0.727 × V(th)init) – 1 . The battery voltage level is checked approximately every 40 seconds during the (approximately) 10 mA, 10 ms LED pulse. If an LED is not used, it should be replaced with an equivalent resistor (typically 500 to 1000 Ω) such that the battery loading remains about 10 mA. I/O A connection to the I/O pin allows multiple smoke detectors to be interconnected. If any single unit detects smoke, its I/O pin is driven high (after a nominal 3 s delay), and all connected units will sound their associated horns. The LED is suppressed when an alarm is signaled from an interconnected unit, and any local alarm condition causes the I/O pin to be ignored as an input. This pin has an on-chip pulldown device and must be left unconnected if not used. Testing On power-up, all internal counters are reset. Internal test circuitry allows low battery check by holding the FEEDBACK and OSC CAP pins low during power-up, then reducing VDD and monitoring the HORN1 pin. HORN1 will be driven high when VDD falls below the low-battery threshold. All functional tests can be accelerated by driving the OSC CAP pin with a 2 kHz square wave. The 10 ms strobe period must be maintained for proper operation of the comparator circuitry. Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 6 Ionization Smoke Detector with Interconnect A5364 Timing Diagrams (Not to scale) Test event Standby Mode OSC CAP Pin tosc tw(osc) Internal Clock Smoke Sample Low Battery Test tw(led) tled1 LED Pin LED off (High-Z) LED on Low Battery Condition (Low battery) VDD Pin Low Battery Test tled1 tw(led) LED Pin LED off (High-Z) thorn tw(horn) LED on Horn Enable Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 7 Ionization Smoke Detector with Interconnect A5364 Local Smoke Detection/Test Alarm Condition tosc(alarm) tw(osc) OSC CAP Pin Test event Internal Clock Smoke Sample LED Pin 24 clock cycles Smoke Sample Smoke Chamber tw(led) LED Pin (no smoke) V DETECTIN < VSENSITIVITYSET (smoke) tled3 LED off (High-Z) LED on toff1(horn) toff 2(horn) ton(horn) Horn Enable tr(io) (Output) I/O Pin Remote Alarm Condition tosc(alarm) OSC CAP Pin Internal Clock I/O Pin LED Pin tw(osc) LED off (High-Z) ton(horn) toff2(horn) toff1(horn) Horn Enable I/O Pin (Input) Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 8 Ionization Smoke Detector with Interconnect A5364 Package A, 16-Pin DIP .750 [19.05] 16 .010 [0.25] .250 [6.35] .430 [10.92] .300 [7.62] A 1 2 .210 [5.33] MAX .130 [3.30] .100 [2.54] .005 [1.27] .060 [1.52] All dimensions nominal, not for tooling use (reference JEDEC MS-001 BB) Dimensions in inches, metric dimensions (mm) in brackets, for reference only Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown A Terminal #1 mark area .018 [0.46] 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 ©2001-2008, Allegro MicroSystems, Inc. The products described here are manufactured under one or more U.S. patents or U.S. 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 permit 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 Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 9