A5364CA-T

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Technical content

200 kΩ 200 kΩ 200 Ω 8.2 MΩ 1 μF 0.1 μF 1.5 MΩ 220 kΩ Push to Test 0.001μF 330 Ω 9 V A B C C C A B Use an external resistor to adjust sensitivity for a particular smoke chamber. C A resistor to VSS or VDD may be added to this pin to modify low battery voltage threshold. Value of component will vary, based on the piezoelectric horn used.

Description

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. 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. 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. 26110.7E Features and Benefits ▪ 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 Ionization Smoke Detector with Interconnect Typical Application Not to scale A5364 Package: 16-pin DIP (suffix A)

2Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A. Number Name Function

1 NC No connection

2 I/O Input/output to interconnected detectors

3 LOW-V SET Optionally used with a resistor to adjust low-battery

4 NC No connection

5 LED Output to drive visible LED

6 VDD Positive supply voltage

7 TIMING RES Terminal for timing resistor, sets internal bias

(affects timing)

8 FEEDBACK Input for driving piezoelectric horn

9 VSS Negative supply voltage

10 HORN1 Output for driving piezoelectric horn

11 HORN2 Complementary output for driving piezoelectric horn

12 OSC CAP Terminal for charging/discharging an external

capacitor to run the oscillator

13 SENSITIVITY SET Optionally used with a resistor to adjust sensitivity

14 GUARD1 Active guard 1 for detector input

15 DETECT IN Input from detector chamber

16 GUARD2 Active guard 2 for detector input

Copyright © 2001, 2002 Allegro MicroSystems, Inc. Selection Guide Part Number Pb-Free Packing A5364CA-T Yes 25 pieces per tube A5364CA – Absolute Maximum Ratings* Characteristic Symbol Notes Rating Units Supply Voltage Range V DD Referenced to VSS –0.5 to 15 V Input Voltage Range V IN Referenced to VSS –0.3 to VDD+ 0.3 V Reverse Battery Condition Duration t RBAT 10.5 V 20 s Input Current I IN 10 mA Operating Ambient Temperature T A 0 to 50 ºC Junction Temperature T J(max) 150 ºC Storage Temperature Range T stg –55 to 125 ºC * CAUTION: CMOS devices have input static protection but are susceptible to damage when exposed to extremely high static electrical charges. Terminal List Table NC I/O LOW-V SET NC LED VDD TIMING RES FEEDBACK GUARD2 DETECT IN GUARD1 SENSITIVITY SET OSC CAP HORN2 HORN1 VSS Pin-out Diagram THERMAL CHARACTERISTICS Characteristic Symbol Test Conditions* Value Units Package Thermal Resistance RθJA 4-layer PCB based on JEDEC standard 38 ºC/W *Additional thermal information available on Allegro website.

3Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. Functional Block Diagram Low Battery Logic Oscillator and Timing Power-on Reset + VDD + VDD VDD VDD I/O FEEDBACK HORN1 HORN2 LED TIMING RES OSC CAP GUARD2GUARD1 SENSITIVITY SET LOW-V SET +Supply VSS -Supply + VDD 600 kΩ 500 kΩ 1.1 MΩ Smoke Comparator Comparator ION CHAMBER Band Gap Low Battery Sample Smoke Sample LBSamp LBSamp SSamp SSamp DETECT IN

4Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. 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) Continued on the next page… Characteristic Symbol Test Conditions Test Pin Min. Typ. Max. Units Supply Voltage Range V DD Operating 6 6.0 9.0 12 V Supply Current I DD VDD = 9.0 V, no alarm, no loads 6 — 5.0 9.0 μA VDD = 12 V, no alarm, no loads 6 — — 12 μA Detector Input Current I DETECTIN 0% to 40% RH, VIN = 0 to 9.0 V 15 — — ±1.0 pA Input Offset Voltage VOS(GUARD1) Active GUARD1 14, 15 — — ±100 mV VOS(GUARD2) Active GUARD2 16, 15 — — ±100 mV VOS Detect comparator 15, 13 — — ±50 mV Hysteresis V HYS No alarm to alarm 13 90 130 170 mV Common Mode Range VCM(guard) Guard amplifi er 14, 15 2.0 — V DD – 0.5 V VCM Smoke comparator 13, 15 0.5 — V DD – 2.0 V Active Guard Impedance ZAG1 GUARD1 to VSS 14 — 10 — k Ω ZAG2 GUARD2 to VSS 16 — 500 — k Ω Oscillator Period tosc No alarm 12 1.34 1.67 2.00 s tosc(alarm) Local or remote alarm 12 32 40 48 ms Oscillator Pulse Width t w(osc) 12 8.0 10 12 ms Low-Battery Threshold V DD(th) TA = 0°C to 50°C, LOW-V SET open circuit 6 7.2 — 7.8 V Sensitivity Adjust Voltage V SET VSENSITIVITYSET / VDD, SENSITIVITY SET open circuit 13 48.5 50 51.5 %V DD Horn Output Voltage VOL IOUT = 16 mA, VDD = 9.0 V 10, 11 — 0.1 0.5 V IOUT = 16 mA, VDD = 7.2 V 10, 11 — — 0.9 V VOH IOUT = –16 mA, VDD = 9.0 V 10, 11 8.5 8.8 — V IOUT = –16 mA, VDD = 7.2 V 10, 11 6.3 — — V Horn Output On-Time ton(horn) Local or remote alarm 10,11 450 500 550 ms tw(horn) Low battery 10, 11 8.0 10 12 ms Horn Output Off-Time toff1(horn) Local or remote alarm (see Timing Diagrams section) 10, 11 450 500 550 ms toff2(horn) Local or remote alarm (see Timing Diagrams section) 10, 11 1350 1500 1650 ms thorn Low battery 10, 11 32 40 48 s LED Output-On Current I LED VDD = 7.2 V, VLED = 1.0 V 5 10 — — mA LED Output On-Time t w(LED) 5 8.0 10 12 ms LED Output Off-Time tLED1 No alarm, in standby 5 32 40 48 s tLED3 Local alarm or test alarm 5 0.76 0.97 1.14 s tLED4 Remote alarm, no local smoke 5 — No LED pulses —s

5Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. 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 com- paring V DD 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 polypro- pylene). Detector Circuitry When the voltage on the DETECT IN pin is less than the volt- age 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 V SENSITIVITYSET 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. V GUARD1 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 ion- ization 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 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 Circuit Description Characteristic Symbol Test Conditions Test Pin Min. Typ. Max. Units I/O Current IIOL No alarm, VI/O = VDD – 2.0 V 2 25 — 60 μA IIOH Local alarm, VI/O = VDD – 2.0 V 2 –7.5 — — mA I/O Alarm Voltage V IH(IO) External “alarm” in 2 3.0 — — V I/O Delay t r(io) Local or test alarm to I/O active 2 — 3.0 — s 1Negative current is defi ned as coming out of the specifi ed device pin (sourcing). 2Alarm (smoke) condition is defi ned as VDETECTIN < VSENSITIVITYSET; no alarm (no smoke) condition is defi ned as VDETECTIN > VSENSITIVITYSET. 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)

6Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. of the ionization chamber by connecting a resistor between the SENSITIVITY SET pin and either the VDD or VSS pins. 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 (nomi- nally 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- nally 7.5 V), and a target threshold, V(th)set , the resistor should have the value: 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 sec- onds 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 cir- cuitry allows low battery check by holding the FEEDBACK and OSC CAP pins low during power-up, then reducing V DD 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.

7Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. Timing Diagrams (Not to scale) OSC CAP Pin Internal Clock LED Pin Smoke Sample Standby Mode Low Battery Test tosc tw(osc) tled 1 LED off (High-Z) LED on tw(led) Test event VDD Pin LED Pin Horn Enable Low Battery Condition (Low battery) tled 1 tw(led) LED off (High-Z) LED on tw(horn) thorn Low Battery Test

8Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. OSC CAP Pin Internal Clock LED Pin Smoke Sample Horn Enable tosc(alarm) 24 clock cycles Local Smoke Detection/Test Alarm Condition I/O Pin tr( io ) (Output) tw(osc) ton(horn) toff2(horn ) toff1(horn) tled3tw(led) LED Pin LED on LED off (High-Z) LED off (High-Z) VDE TE CTI N< VSEN SITIVITYSET (smoke) (no smoke)Smoke Chamber Smoke Sample Test event Horn Enable I/O Pin Remote Alarm Condition (Input) LED Pin ton(horn) toff2(horn) toff1(horn) OSC CAP Pin Internal Clock tosc(alarm ) tw(osc)I/O Pin

9Allegro MicroSystems, Inc. Worcester, Massachusetts 01615-0036 U.S.A. Copyright ©2001-2008, Allegro MicroSystems, Inc. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec i fi ca tions as may be required to per- mit improvements in the per for mance, 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 in for ma tion in clud ed herein is believed to be ac cu rate and reliable. How ev er, Allegro MicroSystems, Inc. assumes no re spon si bil i ty for its use; nor for any in fringe ment 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. Worcester, Massachusetts 01615-0036 U.S.A. Package A, 16-Pin DIP .750 [19.05] .210 [5.33] MAX .300 [7.62] .010 [0.25] .018 [0.46] .100 [2.54] .130 [3.30] .060 [1.52] .005 [1.27] A 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 All dimensions nominal, not for tooling use (reference JEDEC MS-001 BB) Dimensions in inches, metric dimensions (mm) in brackets, for reference only 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