HV860DB1 User Guide

Supertex inc.
HV860DB1
Low Noise, Dimmable
EL Lamp Driver Demoboard
General Description
The Supertex HV860DB1 demoboard contains all necessary
circuitry to demonstrate the features of the HV860 EL lamp
driver.
Simply connect it to a power supply and a lamp as shown in
Figure1. For EL lamp dimming, either a potentiometer or an nchannel open drain PWM signal can be used, but not both.
The potentiometer is used as a variable voltage divider to
change the voltage at the VREG pin. The VREF is voltage divided
to change the VREG voltage thereby changing the VCS voltage.
The VCS voltage amplitude, and thereby the lamp brightness,
increases when the potentiometer is rotated counter-clockwise,
and the lamp brightness decreases when it is rotated clockwise.
Specifications
Parameter
Value
Input voltage:
2.4 to 4.5V
5.5V
VIN inductor supply voltage:
Typical supply current:
10mA
Lamp size:
3.5in2
Lamp frequency:
200Hz
Converter frequency:
150kHz
Board Layout and Connection Diagram
HV860DB1
EN
VDD
RSW
REL
PWM
CDD
VB
RDIM
CDIM
RPWM
Potentiometer
VA
CIN
CS
LX
D
VIN
GND
Actual Dimensions: 20mm x 25mm
Connections:
EN - (Enable Input)
A CMOS logic input which enables/disables the lamp driver. A logic
high (1.5V) enables the driver and a logic low (connect to GND)
disables the driver.
VDD - (IC Supply)
Supplies the HV860 EL driver IC. The supplied demo board is optimized for 3.0V operation, with an operating range from 2.4V to
4.5V. It connects to the positive terminal of a power supply.
PWM - (PWM Input)
Supplies the PWM signal for dimming the EL lamp. The frequency
of this signal can vary between 20kHz and 100kHz. For EL lamp
dimming using the PWM input, either the potentiometer has to be
removed or its value set to for maximum lamp brightness.
The n-channel open drain PWM signal pulls the 10kΩ resistor to
ground. When the duty cycle of this PWM signal is changed, the
effective voltage on the VREG pin is changed. This changes the VCS
voltage, and hence the lamp brightness. The higher the duty cycle,
the higher the lamp brightness, and vice versa.
VA and VB - (Lamp Connections)
They connect to the EL lamp terminals. Polarity is irrelevant.
VIN - (Inductor Supply)
Supplies the high voltage power converter. The demo board is optimized for 5.5V operation. It connects to the 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 required.
Note:
All of the above connections must be made before powering up the supply voltages.
The VREG pin should not be touched after power-up.
Doc.# DSDB-HV860DB1
A032813
Supertex inc.
www.supertex.com
HV860DB1
Figure 1: Circuit Schematic
VIN
+
CIN
4.7μF
-
2
1
2M
Potentiometer
3.3MΩ
3
n-channel Open Drain PWM signal
+
VDD
-
590kΩ
CDD
0.1μF
Cooper Inductor
SD3114-221, 220μH
10kΩ
10
12
1
2.0MΩ
11
ON = 1.5V
OFF = 0V
2
3
VREG
VDD
VREF
HV860K7
5
LX
CS
BAS20HT1
7
3.3nF,
200V
1206 Package
RSW-Osc
REL-Osc
VA
EN
VB
GND
9
EL Lamp
8
4
Typical Performance
The specific external components used in the circuit schematic are: LX = 220μH Cooper (SD3114-221), CS = 3.3nF 200V NPO and the 2MΩ potentiometer.
Brightness
Lamp Size
(in2)
VDD
(V)
VIN
(V)
IIN
(mA)
VCS
(V)
fEL
(Hz)
ft-lm
cd/m2
3.5
3.0
5.2
9.0
110
190
6.20
21.21
3.5
3.0
5.5
8.4
110
190
6.22
21.27
3.5
3.0
5.8
7.9
110
190
6.24
21.33
Bill of Materials
Component
Description
Package
Manufacturer
Part Number
---
Cooper
SD3114-221
LX
220μH inductor
CS
3.3nF, 200V, NPO chip capacitor
1206
Tecate
CMC-200/332JN1206T
RSW
1%, 590kΩ chip resistor
0603
Any
---
REL
1%, 2MΩ chip resistor
0603
Any
---
RDIM
5%, 3.3MΩ chip resistor
0603
Any
---
RPWM
1%, 10kΩ chip resistor
0603
Any
---
CDIM
Optional capacitor for dimming control
---
---
---
CIN
4.7μF, 10V ceramic chip capacitor
0603
Any
---
CDD
0.1μF, 16V ceramic chip capacitor
0603
Any
---
SOD-323
Diodes Inc.
BAS20HT1
---
Bourns Inc.
3352T-205
12-Lead QFN
Supertex
HV860K7
Diode
200V fast recovery diode
POT
2MΩ Potentiometer
U1
EL driver IC
Note:
The above circuit may be optimized further based on specification of the lamp used.
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.
©2013 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited.
Doc.# DSDB-HV860DB1
A032813
100110
2
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com