A5364
Ionization Smoke Detector
with Interconnect
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
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.
Package: 16-pin DIP (suffix A)
Not to scale
Typical Application
A
Use an external resistor to adjust
sensitivity for a particular smoke chamber.
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
200 kΩ
1 NC
200
Ω
To / from
other units
GUARD2
DETECT IN
16
15
14
200 k
Ω
Push
to Test
2
3
I/O
A5364
LOW-V SET
GUARD1
SENSITIVITY SET
OSC CAP
HORN2
HORN1
VSS
B
4 NC
330
Ω
9V
13
12
5
6
LED
VDD
TIMING RES
FEEDBACK
0.1
μF
11
10
9
1.5 MΩ
C
220 kΩ
C
8.2 MΩ
1
μF
7
8
0.001
μF
C
26110.7E
A5364
Selection Guide
Part Number
A5364CA-T
A5364CA
Pb-Free
Yes
–
Packing
25 pieces per tube
Ionization Smoke Detector
with Interconnect
Absolute Maximum Ratings*
Characteristic
Symbol
Notes
Rating
Units
Supply Voltage Range
Input Voltage Range
Reverse Battery Condition Duration
Input Current
Operating Ambient Temperature
Junction Temperature
Storage Temperature Range
V
DD
V
IN
t
RBAT
I
IN
T
A
T
J
(max)
T
stg
Referenced to V
SS
Referenced to V
SS
10.5 V
–0.5 to 15
–0.3 to V
DD
+ 0.3
20
10
0 to 50
150
–55 to 125
V
V
s
mA
ºC
ºC
ºC
* CAUTION: CMOS devices have input static protection but are susceptible to damage when exposed to extremely high static electrical charges.
THERMAL CHARACTERISTICS
Characteristic
Package Thermal Resistance
Symbol
R
θJA
Test Conditions*
4-layer PCB based on JEDEC standard
Value Units
38
ºC/W
*Additional thermal information available on Allegro website.
Terminal List Table
Number
1
2
Name
NC
I/O
LOW-V SET
NC
LED
VDD
TIMING RES
FEEDBACK
VSS
HORN1
HORN2
OSC CAP
SENSITIVITY SET
GUARD1
DETECT IN
GUARD2
Function
No connection
Input/output to interconnected detectors
Optionally used with a resistor to adjust low-battery
threshold
No connection
Output to drive visible LED
Positive supply voltage
Terminal for timing resistor, sets internal bias
(affects timing)
Input for driving piezoelectric horn
Negative supply voltage
Output for driving piezoelectric horn
Complementary output for driving piezoelectric horn
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
Pin-out Diagram
3
4
NC 1
I/O 2
LOW-V SET 3
NC 4
LED 5
VDD 6
TIMING RES 7
FEEDBACK 8
16 GUARD2
15 DETECT IN
14 GUARD1
13 SENSITIVITY SET
12 OSC CAP
11 HORN2
10 HORN1
9 VSS
5
6
7
8
9
10
11
12
13
14
15
16
Copyright © 2001, 2002 Allegro MicroSystems, Inc.
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
A5364
Ionization Smoke Detector
with Interconnect
Functional Block Diagram
I/O
+Supply
9V
VDD
Band
Gap
V
DD
FEEDBACK
LBSamp
HORN2
HORN1
Low Battery
Sample
600 kΩ
_
Low Battery
Comparator
Logic
LED
+ V
DD
LOW-V SET
+
500 kΩ
+
_
Smoke
Comparator
Smoke
Sample
1.1 MΩ
LBSamp
SSamp
Oscillator
and Timing
OSC CAP
Power-on
Reset
TIMING RES
SENSITIVITY SET
SSamp
+ V
DD
-Supply
VSS
+
_
GUARD1
DETECT IN
GUARD2
+ V
DD
ION CHAMBER
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
A5364
Ionization Smoke Detector
with Interconnect
ELECTRICAL CHARACTERISTICS
1,2
at T
A
= 25°C, V
DD
= 9.0 V, V
SS
= 0 V, C
OSCCAP
= 0.1
μF,
R
TIMINGRES
= 8.2 MΩ (unless otherwise noted)
Characteristic
Supply Voltage Range
Supply Current
Detector Input Current
Input Offset Voltage
Hysteresis
Common Mode Range
Active Guard Impedance
Oscillator Period
Oscillator Pulse Width
Low-Battery Threshold
Sensitivity Adjust Voltage
Symbol
V
DD
I
DD
I
DETECTIN
V
OS(GUARD1)
V
OS(GUARD2)
V
OS
V
HYS
V
CM(guard)
V
CM
Z
AG1
Z
AG2
t
osc
t
osc(alarm)
t
w(osc)
V
DD(th)
V
SET
V
OL
Horn Output Voltage
V
OH
Horn Output On-Time
t
on(horn)
t
w(horn)
t
off1(horn)
Horn Output Off-Time
t
off2(horn)
t
horn
I
LED
t
w(LED)
t
LED1
t
LED3
t
LED4
Test Conditions
Operating
V
DD
= 9.0 V, no alarm, no loads
V
DD
= 12 V, no alarm, no loads
0% to 40% RH, V
IN
= 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
T
A
= 0°C to 50°C,
LOW-V SET open circuit
V
SENSITIVITYSET
/ V
DD
,
SENSITIVITY SET open circuit
I
OUT
= 16 mA, V
DD
= 9.0 V
I
OUT
= 16 mA, V
DD
= 7.2 V
I
OUT
= –16 mA, V
DD
= 9.0 V
I
OUT
= –16 mA, V
DD
= 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
V
DD
= 7.2 V, V
LED
= 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
6
13
10, 11
10, 11
10, 11
10, 11
10,11
10, 11
10, 11
10, 11
10, 11
5
5
5
5
5
Min.
6.0
—
—
—
—
—
—
90
2.0
0.5
—
—
1.34
32
8.0
7.2
48.5
—
—
8.5
6.3
450
8.0
450
1350
32
10
8.0
32
0.76
—
Typ.
9.0
5.0
—
—
—
—
—
130
—
—
10
500
1.67
40
10
—
50
0.1
—
8.8
—
500
10
500
1500
40
—
10
40
0.97
No LED
pulses
Max.
12
9.0
12
±1.0
±100
±100
±50
170
V
DD
– 0.5
V
DD
– 2.0
—
—
2.00
48
12
7.8
51.5
0.5
0.9
—
—
550
12
550
1650
48
—
12
48
1.14
—
Units
V
μA
μA
pA
mV
mV
mV
mV
V
V
kΩ
kΩ
s
ms
ms
V
%V
DD
V
V
V
V
ms
ms
ms
ms
s
mA
ms
s
s
s
LED Output-On Current
LED Output On-Time
LED Output Off-Time
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
A5364
Ionization Smoke Detector
with Interconnect
ELECTRICAL CHARACTERISTICS
1,2
(continued) at T
A
= 25°C, V
DD
= 9.0 V, V
SS
= 0 V, C
OSCCAP
= 0.1
μF,
R
TIMINGRES
= 8.2 MΩ (unless otherwise noted)
Symbol
Test Conditions
Test Pin
Min.
Typ.
Max.
Units
No alarm, V
I/O
= V
DD
– 2.0 V
2
25
—
60
μA
I
IOL
I/O Current
Local alarm, V
I/O
= V
DD
– 2.0 V
2
–7.5
—
—
mA
I
IOH
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
1
Negative current is defined as coming out of the specified device pin (sourcing).
2
Alarm (smoke) condition is defined as V
DETECTIN
< V
SENSITIVITYSET
; no alarm (no smoke) condition is defined as V
DETECTIN
> V
SENSITIVITYSET
.
Characteristic
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 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 V
GUARD2
will be within 100 mV of V
DETECTIN
. 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
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
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