HV823DB1 User Guide

Supertex inc.
HV823DB1
EL Driver
Demoboard
General Description
Specifications
The HV823DB1 EL Driver demoboard contains all the circuitry
necessary to drive an EL (Electroluminescent) lamp. Simply
connect it to a power supply and a lamp as shown below.
Parameter
The supplied circuit has been optimized to drive an 8.0in2 lamp
from a 3.0 to 3.3V supply. The circuit may be customized with
different component values to suit a particular application.
To assist in customization, various circuits optimized for a
variety of applications are provided. For additional assitance
in designing EL driver circuits, please refer to AN-H34 (HV823
& HV825 EL Lamp Driver Circuits).
Lamp size range
3.0 to 12in2
Lamp frequency
~260Hz
Converter frequency
~50KHz
Value
Supply voltage
3.0 to 3.3V
Supply current
~50mA
Board Layout and Connections
Enable
Off
connect together
On
CDD
RSW
REL
CSW
EN
VA
VDD
3.0 - 3.3V
GND
823
L
VIN
C
D
C
VB
EL Lamp
HV823DB1
Connections:
EN - Enable Input
Enables/disables the lamp driver. A logic high (VDD) enables
the driver and a logic low (GND) disables the driver. This
input may be connected to a mechanical switch as shown,
or to a logic circuit output that has a source impedance of
less than 20KΩ.
VDD - IC Supply
Supplies the HV823 EL driver IC. The supplied circuit is optimized for 3.0V to 3.3V operation. Current draw is typically
100µA when enabled and less than 1µA when disabled.
Doc.# DSDB-HV823DB1
B032114
VIN - Inductor Supply
Supplies the high voltage power converter. Current draw is
approximately 50mA.
GND - Circuit Ground
Connect to VDD negative terminal. Supply bypass capacitors
for both VDD and VIN are provided on the demoboard. An external supply bypass capacitor is not necessary.
VA and VB - Lamp Connections
Connect to EL lamp of 3 to 12 square inches. Polarity is irrelevant.
Supertex inc.
www.supertex.com
HV823DB1
HV823DB1 Circuit Schematic
Enable
REL-Osc
3.0MΩ
ON = VDD
OFF = GND
VDD
RSW-Osc
1.0MΩ
Note 1
VIN
L
220µH
CDD
100nF
D
1N4148
CIN
4.7µF
CS
10nF
CSW
1.0nF
VDD
REL
RSW
VA
CS
VB
LX
GND
EL
Lamp
HV823
GND
Note:
1. Tie VDD and VIN together if split suppies are not used.
CDD is not needed when a single supply is used.
Modifiying the Supplied Circuit
order of lamp size, along with supply voltages and component values. Find the circuit that most closely matches the
desired application and change components as needed. For
component locations, refer to the board layout and connection diagram at the begining of this note.
The supplied circuit is optimized to drive an 8.0in2 green lamp
from a 3.0 to 3.3V supply. To better suit other applications,
the circuit may be modified by changing one or more of the
components. The following table lists various applications in
(ft-lm)
Lamp
Color
Lamp
Freq
1.5
4.8
Green
260
3.0
same
1.7
6.6
Green
400
3.0
3.5
6.2
Green
400
6.0
3.0
Green
7.0
5.8
7.0
Lamp
Size
Lamp1
Brightness
VDD
VIN
Current
VIN2
Component Values
(µH)
(MΩ)
(KΩ)
(nF)
CS
CSW
10
1000
3.3
680
100
none
1.0 - 1.5
35
220
2.0
1000
100
none
3.3
same
25
560
2.0
750
100
none
170
3.3
same
21
560
5.1
680
100
none
Green
400
5.0
same
30
560
2.0
680
10
1.0
7.8
Green
400
9.0
same
23
560
2.0
680
10
1.0
8.0
6.2
Green
400
5.0
same
30
560
2.0
820
10
1.0
9.0
4.7
White
800
5.0
12
12
560
1.0
330
100
1.0
10
4.1
Green
260
5.0
same
22
1000
3.3
680
10
1.0
12
5.2
Green
260
3.3
same
51
220
3.0
680
10
none
12
3.2
Green
260
5.0
same
19
560
3.0
330
10
1.0
13
3.1
White
400
5.0
same
34
560
2.0
680
10
1.0
13
6.6
White
400
9.0
same
35
560
2.0
680
10
1.0
23
2.1
Green
250
3.3
same
48
330
3.3
1000
10
1.0
(in2)
(Hz)
(V)
(V)
(mA)
L
3
REL
RSW
(nF)
Notes:
1. Lamp brightness can vary by type and manufacturer.
2. ‘same’ in the VIN column indicates that VIN and VDD are connected together to the same power supply.
3. The recommended inductor is a Murata LQH4N series. Other inductors may be used, however, different inductor characteristics (especially
series resistance) may result in overall circuit performance different from that listed. Please refer to Application Note AN-H33 for more information.
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives
an adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability
to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and
specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com)
Supertex inc.
©2014 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited.
Doc.# DSDB-HV823DB1
B032114
2
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com