AUTOMOTIVE AND HOUSEHOLD
SECURITY SIREN DRIVER
ISSUE 8 – JUNE 2007
INTRODUCTION
The ZSD100 is a frequency swept alarm
signal generator designed specifically for
static and automotive security alarm
s y st e ms . On e Z SD 1 0 0 , t w o t i mi n g
capacitors, an in-expensive TO92 darlington,
piezo transducer and coupling transformer
is all that is necessary to produce an ear
piercing 120 dB alarm siren.
Including an audio frequency signal
generator, low frequency sweep generator,
disable circuitry and output driver stages,
the ZSD100 provides every function
necessary to produce a standard alarm
signal. Available in an 8 pin SO package,
the IC gives a low cost compact solution
to siren signal generation. The device
operates from supplies of 4V up to 18V
and is ideal for security alarms in battery
powered applications, burglar alarms and
automotive anti theft systems.
ZSD100
FEATURES
•
•
•
•
•
•
•
•
•
•
4-18V Operating voltage range.
Small external component count.
Direct drive of darlington, mosfet and
IGBT output stages.
Single ended or push-pull output
stages.
Suitable for automotive and static
alarm systems.
Low supply current - 10mA operating
- 1µA sleep mode
Low cost 8 pin SO package.
User selected audio and sweep
frequencies.
-40°C to 125°C operating temperature
range.
Choice of modulation waveform.
SCHEMATIC DIAGRAM
R
T
(INT)
R
T
C
MOD
SAW
Low
Frequency
Oscillator
Output
Driver
Control
Voltage
Audio
Voltage
Controlled
Oscillator
Oscillator
Output
C
OUT
Q
Q
Issue
8
-
June 2007
© Zetex Semiconductors plc 2007
ZSD100
FUNCTIONAL DESCRIPTION
The audio signal of the ZSD100 is generated using a squarewave oscillator whose output is capable
of directly driving a wide range of output circuits. To produce a characteristic alarm siren sound, the
frequency of the audio oscillator is swept over a fixed 2:1 range by a second, low frequency oscillator.
The freqencies of both oscillators are controlled by R
T
(INT) and capacitors C
MOD
and C
OUT
.
R
T
(INT)
R
T
C
MOD
SAW
Low
Frequency
Oscillator
Output
Driver
Control
Voltage
Audio
Voltage
Controlled
Oscillator
Oscillator
Output
C
OUT
Q
Q
PIN DESCRIPTIONS
1.
R
T
Optional external resistor for improved frequency control. An external resistor
improves the control of both the modulating and output oscillators.
The R
T
pin is also used to power the device down. Either connecting R
T
to V
CC
or
an open circuit will result in the device being disabled.
Selection of modulation waveform is made using the SAW pin. An open circuit
produces a triangle wave, sawtooth is achieved by connecting SAW to the C
MOD
pin.
An external capacitor is used to program the low frequency modulating oscillator.
The value of C
MOD
recommended is between 0.1µF and 100µF.
2.
SAW
3.
C
MOD
4.
5.
G
ND
C
OUT
An external capacitor is used to program the output oscillator. The value of C
OUT
recommended is between 1nF and 100nF.
Non inverted output driver
Inverted output driver
6.
7.
8.
Q
Q
V
CC
Issue
8
-
June 2007
© Zetex Semiconductors plc 2007
www.zetex.com
ZSD100
TYPICAL CHARACTERISTICS
20
I
SOURCE
- Output Source Current (mA)
I
SINK
- Output Sink Current (mA)
V
CC
=12V
10
Q
V
CC
=12V
16
8
Q or Q
6
4
12
8
Q
4
0
0
2
4
6
8
10
2
0
0
2
4
6
8
10
12
V
OUT
- Output Voltage (V)
V
OUT
- Output Voltage (V)
I
SINK
v
V
OUT
I
SOURCE
v
V
OUT
F
MOD
- Normalised Modulation Frequency
1.2
F
O
- Normalised Output Frequency
R
T
=470k
1.2
R
T
=0
1.0
R
T
=470k
1.0
R
T
=0
0.8
0.6
0.8
0.6
F
O
at V
CC
=12V = 1.4kHz
0.4
0.2
0
4
8
12
16
20
0.4
0.2
0
4
8
12
16
20
V
CC
- Supply Voltage (V)
V
CC
- Supply Voltage (V)
F
MOD
vV
CC
F
O
vV
CC
F
OUT
- Output Centre Frequency (kHz)
10
F
MOD
- Modulation Frequency (Hz)
10
R
T
=0
R
T
=0
1.0
1.0
R
T
=470k
0.1
1.0
10
100
R
T
=470k
0.1
1
10
100
C
OUT
- Output Oscillator Capacitance (nF)
C
MOD
- Modulation Capacitance (µF)
F
OUT
vC
OUT
F
MOD
v C
MOD
Issue
8
-
June 2007
© Zetex Semiconductors plc 2007
www.zetex.com
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