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HV832DB1
HV832DB1
Dual EL Lamp Driver
Introduction
The Supertex HV832DB1 demo board contains all necessary
circuitry to demonstrate the features of the HV832 dual EL lamp
driver.
Simply connect it to a power supply and a lamp as shown below.
For additional assistance in designing EL driver circuits, please
refer to application notes AN-H33 (effect of external components
on performance of Supertex EL drivers), application note ANH44 (HV832 application circuits), and AN-H43 (EL lamp driver
circuits to reduce lamp audible noise).
Board Layout and Connections
V
C
DD
Re
Ce
DD
Specifications
Input Voltage 3.0V to 4.2V
Supply Current 40mA Max.
Lamp Size Range Up to 2.7in
Lamp Frequency 417Hz
Converter Frequency 53.4KHz
EL1
HV832
LX
Com
Com
Diode
EL2
Cs
2
EN-SW
Demo Board Connections:
Control lamp selection/Enable Input (EN-SW)
Various modes of the device are selected via the control pin/ENSW. Each logic pulse applied to the control pin/EN-SW will
cause the device to change to the next mode. The sequence for
the modes is: 1) EL1 on, 2) EL2 on, 3) both EL1 and EL2 on, and
4) device shuts down. This input may be connected to a
mechanical switch, or to a logic circuit output that has a source
impedance of less than 20KΩ.
VDD IC Supply
Supplies the HV832 EL driver IC. The supplied circuit is
optimized for 3.0 to 4.2 volt operations. Connect to positive
terminal of a power supply.
V
IN
C
IN
GND
VIN Inductor Supply
Supplies the high voltage power converter. Connect to positive
terminal of a power supply.
GND Circuit Ground
Connect to VDD and VIN negative terminals. Supply bypass
capacitor for both VDD and VIN are provided on the demo board.
External supply bypass capacitors are not necessary.
EL1 and EL2 Lamp Connections
Connects to lamps 1 and 2. Polarity is irrelevant.
Com Lamp Connections
Connects to the other side of lamps 1 and 2. Polarity is irrelevant.
12/14/01
Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability
indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to
workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the
Supertex website: http://www.supertex.com. For complete liability information on all Supertex products, refer to the most current databook or to the Legal/Disclaimer page on the Supertex website.
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Ce**
HV832DB1
HV832DB1 Schematic
EN-SW
10KΩ
10nF
+
V
DD
-
+
V
IN
-
Re**
0.1µF
4.7µF
1
EL1
V
2
Control
3
GND
4
DD
HV832MG
EL2
Com
8
7
C
6
S
L
5
X
1N914*
390µH
EL Lamp 1
EL Lamp 2
3.3nF
100V
390µH MuRata (
Lx =
* Any (equivalent or better)> 90V, fast reverse recovery diode
** Re and Ce are used to prevent change in lamp selection due to use of
mechanical switch which can have contact bounce.
LQH32CN391K21)
Typical Performance
The specific external components used in the above circuit are LX=390µH Murata (LQH32CN391K21), Cs= 3.3nF 100V NPO.
The following was observed when driving a 0.93in2 Green lamp.
VDD)V(VNI)V(
3.33.3
0.3
pmaL
I
)Am(VSC)V(fLE)zH(
NI
noitceleS
2ro1pmaL9.027.08
ml-tfm/dc
57.112.04
spmalhtoB1.130.3746.014.63
2ro1pmaL9.124.8743.118.83
0.3
spmalhtoB0.231.0728.96.33
714
2ro1pmaL3.128.9746.118.93
2.3
spmalhtoB4.133.2792.012.53
2ro1pmaL3.912.5834.215.24
2.4
spmalhtoB3.820.1885.116.93
ssenthgirB
2
The following was observed when driving EL1=1.3in2 and EL2=0.93in2 Green lamps.
VDD)V(VNI)V(
pmaL
I
)Am(VSC)V(fLE)zH(
NI
noitceleS
1LE8.323.18
3.33.3
2LE9.027.0857.112.04
714
spmalhtoB2.437.1795.98.23
The above circuit may need to be optimized further based on specification of the lamp used.
1235 Bordeaux Drive, Sunnyvale, CA 94089
©2001 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited.
2
TEL: (408) 744-0100 • FAX: (408) 222-4895
ml-tfm/dc
97.019.63
ssenthgirB
2
12/13/01rev.4
www.supertex.com
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