BL59A12/BL59S12
PHOTOELECTRIC SMOKE DETECTOR IC
1. Product description
1.1 Basic function:
BL59A12 (BL59S12) is a CMOS LSI used for smoke detection. Ultra-low power analog and
digital circuits are contained in it. Combined with an IR photoelectric chamber, this IC is used to
detect smoke through receiving light scattered by tiny smoke particles going into the chamber.
When smoke is detected, a burst of alarm sounds are generated by an external piezoelectric
buzzer driven by the push-pull output of this IC.
1.2. Applications:
Smoke detection system.
2. Features:
Power supply range: 6V
½
12V
Average supply current: 8uA
Operating temperature range: -10
½
60℃
Ideal for battery powered applications.
3. Block diagram of this IC
4.Pin assignment
http://www.belling.com.cn
-1-
8/28/2006
Wrote by 2006
Total
8 Pages
BL59A12/BL59S12
5.Pin description
Pin
Symbol
No.
1,2
C1, C2
Input/output
External
capacitor
connection
I
Detecting
input
Strobe
Power supply
O
Output signal
Functions
By connecting external capacitor, a
voltage feedback amplifier is formed.
The gain of it is determined by
capacitor’s value.
Connect a photodiode to supply a
signal to the internal comparator.
A strobe voltage output, referenced to
VDD.
When output = VDD -5V, it enables
other internal circuits.
To supply the power
To output pulse drive signal for
external NPN transistor which drives
a IR photodiode.
It can be used to connect up to 40
detectors to make auxiliary alarm,
remote alarm, auto-dialer…
Push-pull driver outputs signal to
drive external buzzer to alarm, and to
show various operation states.
To feed ‘silver’ signal back to the
push-pull output driver circuit’s input
It is an open drain output, can drive
LED directly. The LED can tell the
detector’s various operation states.
Connected to external R and C, which
determine the internal oscillator’s
frequency.
Connected to external R and C, which
determine the output pulse period of
IRED.
It connected to external resistor
divider between VDD and LED to get
a low supply alarm threshold voltage
This pin is normally low by an internal
pull-down device. When it is set high,
the IC enters into a simulated-smoke
condition. When floating, this pin
comes back to VSS (low) by
pull-down device.
3
DETECT
4
5,14
6
STROBE
VDD, GND
IRED
O
7
I/O
BRASS,
SILVER
FEEDBACK
LED
Input/output
Push-pull
driver’s output
Feedback
terminal
Output signal
Oscillator’s
input
External R and
C connecting
terminal
I
Low
voltage
detecting input
8,9
10
11
O
I
O
12
OSC
I
13
R1
15
LOW-SUPPLY
16
TEST
I
Test terminal
6. Function of this IC:
6.1.
The variable gain photoelectric amplifier is directly connected to IR detector (photodiode).
The amplifier’s gain is determined by external capacitors C1 and C2. During standby, the
amplifier’s gain is at minimum. Under smoke condition, the amplifier’s gain is at medium.
Entering into test condition, the amplifier’s gain is at maximum. Additionally, under standby
state, if the special supervisory circuit is activated to check the chamber’s sensitivity, the
amplifier’s gain is also at its maximum.
6.2.
Using VSS as its reference, the I/O pin can be used to connect up to 40 units together.
When I/O pin is used as an input, its on-chip pull-down resistor can prevent noise from entering
into the unit. Under smoke status, the unit activates I/O driver to send a signal to its
interconnected units to activate remote alarm.
http://www.belling.com.cn
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Total
8 Pages
BL59A12/BL59S12
6.3.
Display method: LED (connected to LED pin) flashing combined with alarm sound,
indicates a LOCAL SMOKE condition. Only pulsating alarm sound without LED flashing
indicates a REMOTE SMOKE condition.
7. Specifications:
7.1. Absolute maximum ratings(VSS as reference)
Symbol
Parameter
VDD
Supply voltage
C1, C2, Detect
OSC, low-supply trip
I/O
Feedback
Test
DC input current
DC output current
Supply current
Power dissipation in still air, 5Sec
Continuous
Storage temperature
Limits
-0.5
½
+12
-0.25
½Vdd+0.25
-0.25
½Vdd+0.25
-0.25
½Vdd+0.25
-15
½+15
-1.0
½Vdd+0.25
±10
±25
+25/-150
1200
350
-55
½125
mA
mA
mA
mW
℃
Units
VIN
DC input voltage
V
IIN
IOUT
IDD
PD
TSTG
7.2 DC Electrical characteristics(Ta=25℃,VSS as reference, unless otherwise indicated)
℃
Symbol
VDD
VTH
Parameters
Power supply voltage
range
Supply threshold voltage,
Low supply alarm voltage
Average supply current
Test condition
VDD
--
Low supply trip
voltage
VIN = VDD/3
Standby,
(See sample
figure)
Strobe on,
IRED off
(See sample
figure)
Min.
6.0
6.5
Max.
12
7.8
Unit
V
V
IDD
12
--
8
uA
iDD
Supply peak current
Low level input voltage,
I/O
Feedback
Test
High level input voltage
I/O
Feedback
Test
Input current OSC,
Detect
Low supply trip
Feedback
Low level input current
TEST
Pull-down current Test
I/O
12
--
2.0
mA
VIL
9.0
9.0
9.0
9.0
9.0
9.0
VIN = VSS or
VDD
VIN = VSS or
VDD
VIN = VSS or
VDD
VIN = VSS
VIN = VDD
No local smoke,
VIN = VDD
No local smoke,
VIN = 17V
-3-
1.5
2.7
7.0
3.2
6.3
8.5
±100
±100
±100
-1
0.5
25
--
10
100
140
V
VIH
V
IIN
12
12
12
nA
IIL
12
9.0
9.0
12
uA
IIH
uA
http://www.belling.com.cn
8/28/2006
Wrote by 2006
Total
8 Pages
BL59A12/BL59S12
VOL
VOH
Low level output voltage,
LED
Silver, Brass
High level output voltage
Silver, Brass
IOUT = 10mA
IOUT = 16mA
IOUT = -16mA
Inactive,
IOUT = -1uA
Active, IOUT =
100uA to 500uA
(load regulation)
Inactive,
IOUT =-1uA
Active, IOUT
=6uA
(load regulation)
Local smoke,
VOUT =4.5V
Local smoke,
VOUT = VSS
(short-circuit
current)
VOUT = VSS or
VDD
Local smoke,
Pushbutton test
or chamber
sensitivity test
Local smoke,
pushbutton test
or chamber
sensitivity test
6.5
6.5
6.5
-
9.0
5.5
VDD-0.1
VDD-4.4
-
Vdd-5.6
V
-
9.0
-
2.25
0. 1
3.75
0.6
1.0
-
V
V
Strobe
VOUT
Output
voltage
(See
pin
description)
IRED
6.5
-4
--
mA
IOH
High-level output current,
I/O
12
--
-16
IOZ
Output off-state leak
current,
LED
Common-mode voltage
range
C1, C2, Detect
Internal reference voltage
of smoke comparator
12
-
±1
uA
VIC
--
VDD -4
VDD -2
V
VREF
--
VDD-3.08
VDD-3.92
V
7.3 AC ELECTRICAL CHARACTERISTICS
(T
A
= 25℃,V
DD
= 9.0 V, Component Values: R1 = 100.0 K, C3 = 1500.0 pF, R2 = 7.5 MΩ)
Symbol
1/f
osc
Parameters
Oscillator Period
Test condition
Free-Running
Sawtooth
Measured at Pin
12
No Local Smoke,
and
No Remote
Smoke
Remote Smoke,
but
No Local Smoke
Local Smoke or
Pushbutton Test
Clocks
1
Min
*
Typ
**
Max
8.6
*
Unit
ms
7.0
7.9
4096
28.8
32.4
35.2
s
t
LED
LED Pulse
Period
-
64
1
0.45
7.0
7.2
28.8
0.9
94
Extinguished
0.5
-
8.1
32.4
1.0
0.55
8.6
8.8
35.2
1.1
116
s
ms
t
w(LED)
,
t
w(stb)
LED Pulse Width
and Strobe Pulse
Width
Smoke Test
Chamber
Sensitivity Test,
without Local
Smoke
Pushbutton Test
1024
4096
128
Tf*
t
IRED
IRED Pulse
Period
t
w(IRED)
IRED Pulse
-4-
us
http://www.belling.com.cn
8/28/2006
Wrote by 2006
Total
8 Pages
MEMS传感器
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