Page 1
Dual High Voltage, Low Noise EL Lamp Driver
HV832
HV832
Features
❏ 8-pin dual EL driver IC
❏ Input control for lamp selection
❏ Split supply capability
❏ Patented output timing
❏ One minature inductor to power both lamps
❏ 150nA shutdown current
❏ Wide input voltage range (2.0V to 5.0V)
❏ Output voltage regulation
❏ No SCR output
Applications
❏ Dual display cell phones
❏ Keypad and LCD backlighting
❏ Dual segment lamps
❏ Handheld wireless communication devices
General Description
The Supertex HV832 is a high voltage driver designed for driving
two EL lamps with a combined area of 3.5 square inches. The
input supply voltage range is from 2.0V to 5.0V. The device is
designed to reduce the amount of audible noise emitted by the
lamp. The device uses a single inductor and a minimum number
of passive components. The nominal regulated output voltage
that is applied to the EL lamp is ±90V.
The HV832 has an internal oscillator, a switching MOSFET, and
two high voltage EL lamp drivers. The frequency for the switching
MOSFET is set at 51KHz nominal. The EL lamp driver frequency
is set by dividing the MOSFET switching frequency by 128. An
external inductor is connected between the L
for split supply applications. A 0.001 to 0.01µF, 100V
V
IN
capacitor is connected between C
are connected between EL
1
and Ground. The EL lamps
S
to Com and EL2 to Com.
An input control pin is available to select various modes of the
device. Each logic pulse applied to the control pin will cause the
device to change to the next mode. The sequence for the modes
is: (1) EL
on only , (2) EL2 on only , (3) both EL1 and EL2 on, and
1
(4) device shuts down. During power up of the device, the mode
will default to shut down.
The switching MOSFET charges the external inductor and
discharges it into the capacitor at Cs. The voltage at CS will start
to increase. Once the voltage at Cs reaches a nominal value of
90V , the switching MOSFET is turned off to conserve power. The
outputs EL
to Com and EL2 to Com are configured as H bridges
1
EL1/EL2 and Com are switching in opposite states to achieve
180V across the EL lamp.
and VDD pins or
X
T ypical Application
V
DD
Logic Input Pulse
1
EL
1
V
2
DD
Control
3
GND L
+
V
IN
_
12/13/01
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.
C
IN
4
HV832MG
1
EL
Com
C
8
2
7
6
S
5
X
L
X
EL Lamp 1
C
S
EL Lamp 2
Page 2
Electrical Characteristics
HV832
DC Characteristics (Over recommended operating conditions unless otherwise specified, T
= 25°C)
A
Symbol Parameter Min Typ Max Units Conditions
R
DS(ON)
V
CS
V
diff
I
DDQ
I
DD
I
IN
On-resistance of switching transistor 7.0 Ω I = 100mA
Output regulation voltage 80 90 100 V V
differential output voltage across each lamp
(EL1 to Com, EL2 to Com)
160 180 200 V V
= 2.0V to 5.0V
DD
= 2.0V to 5.0V
DD
Quiescent VDD supply current 150 nA
Input current into VDD pin 150 µAV
Input current including inductor current
27 32
mA
38 43
= 2.0V to 5.0V
DD
V
= 3.0V.
IN
Driving EL1 or EL2.
See Figure 1.
V
= 3.0V.
IN
Driving both EL1 and EL2.
See Figure 1.
V
CS
f
EL
f
SW
f
SW Drift
Output voltage on V
CS
68 78 87
V
62 70 78
V
output drive frequency 350 400 450 Hz V
diff
Switching transistor frequency 44.8 51.2 57.6 KHz V
= 3.0V. Driving EL1 or
V
IN
EL2. See Figure 1.
= 3.0V. Driving both EL1
V
IN
and EL2, See Figure 1.
= 3.0V. See Figure 1.
IN
= 3.0V. See Figure 1.
IN
Switching transistor frequency Drift +/- 5.0 KHz TA = -40°C to +85°C
D Switching transistor duty cycle 85 % See Figure 1.
I
IL
I
IH
V
IL
V
IH
* The inductor used is a 330uH Murata inductor, max DC resistance of 10 Ohms, part # LQH32CN331.
Input logic low current going
into the control pin.
0.6
µA
Input logic high current going
into the control pin.
0.6
Logic input low voltage 0 0.25 V
Logic input high voltage 1.75 V
DD
V
= 2.0V to 5.0V.
V
DD
See Figure 1.
Recommended Operating Conditions
Symbol Parameter Min Typ Max Units Conditions
V
DD
T
A
Absolute Maximum Ratings*
Supply voltage, V
Output voltage, V
Operating Temperature Range -40°C to +85°C
Storage Temperature Range -65°C to +150°C
8 Pin MSOP Power Dissipation 300mW
* All voltages are referenced to ground.
Supply voltage 2.0 5.0 V
Operating temperature -40 85 °C
Ordering Information
DD
C
S
-0.5V to 7.5V
-0.5V to +120V
Device MSOP-8 Die
HV832 HV832MG* HV832X
* Product supplied on 2500 piece carrier tape reels.
2
Package Options
Page 3
Function Table
Control Pin EL
1
Power up HI Z HI Z HI Z OFF
1st pulse L to H ON HI Z ON ON
2nd pulse L to H HI Z ON ON ON
3rd pulse L to H ON ON ON ON
th
pulse L to H HI Z HI Z HI Z OFF
4
EL
2
Com IC
Pin Configuration
HV832
EL
1
1
2
V
DD
Control V
GND L
3
4
8
7
6
5
top view
MSOP-8
EL
2
Com
CS
X
3
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Functional Block Diagram
V
DD
Control
GND
Control Logic &
Switch Osc
Disable
HV832
L
X
C
S
EL
+
C
_
Vref
Vsen
1
EL Osc =
Switch Osc ÷ 128
High
Voltage
Level
Trans-
lator
Figure 1: Typical Application Circuit/Test Circuit
V
= V
DD
EL
Com
IN
8
2
7
V
DD
Logic Input Pulse
1
EL
1
V
2
DD
EL
2
Com
EL Lamp 1=1.5in
EL Lamp 2=1.5in
2
2
Control
3
GND L
+
V
IN
_
eciveDpmaLV
LE
1
GM238VH
LEhtoB
4.7µF
LEro
NO
2
LEdna
1
NOAm83V07ml-tf2.6
2
4
DD
V0.3
C
6
HV832MG
S
5
X
IN914*
L
X
330µH
3.3nF
100V
LX = 330µH Murata (LQH32CN331)
* any (equivalent or better) >90V, fast reverse recovery diode
I
DD
Am72V87
V
SC
f
LE
ssenthgirB
ml-tf5.7
zH004
4
Page 5
Typical Performance Curves for Figure 1 with one output ON
(EL Lamp=1.5in
2
, VDD=3.0V)
HV832
100
90
80
V)
CS (
70
V
60
50
1.5 2 2.5 3 3.5 4 4.5 5 5.5
10
)
9
8
(ft-lm
7
6
5
Brightness
4
1.5 2.5 3.5 4.5 5.5
Vcs vs Vin
Vin (V)
Brightness vs Vin
Vin (V)
30
28
26
mA)
(
24
lin
22
20
1.5 2.5 3.5 4.5 5.5
30
28
26
mA)
(
24
lin
22
20
60 65 70 75 80 85 90 95
Iin vs Vin
Vin (V)
Iin vs Vcs
Vcs (V)
90
80
70
60
50
40
30
IIN (mA), VCS (V)
Iin(mA), Vcs(V)
20
10
0
200 300 400 500 600
IIN, VCS, Brightness vs. Inductor Value
Iin, Vcs, Brightness vs. Inductor Value
Brightness
Iin
Inductor Value (µH)
Vcs
10
9
8
7
Brightness (ft-lm)
6
5
5
Page 6
HV832
1
_
C
5
G
V
l
D
m
V
e
External Component Description
External Component Selection Guide Line
Diode Fast reverse recovery diode, IN914 or equivalent.
Cs Capacitor 0.003µF to 0.1µF, 100V capacitor to GND is used to store the energy transferred from the inductor.
Lx Inductor The inductor Lx is used to boost the low input voltage by inductive flyback. When the internal switch is on,
the inductor is being charged. When the internal switch is off, the charge stored in the inductor will be
transferred to the high voltage capacitor CS. The energy stored in the capacitor is connected to the internal
H-bridge and therefore to the EL lamp. In general, smaller value inductors, which can handle more current,
are more suitable to drive larger size lamps.
Lamp As the EL lamp size increases, more current will be drawn from the battery to maintain high voltage across
the EL lamp. The input power, (V
dissipation of the package (300mW), an external resistor in series with one side of the lamp is recommended
to help reduce the package power dissipation.
Split Supply Configuration
The HV832 can also be used for handheld devices operating
from a battery where a regulated voltage is available. This is
shown in Figure 2. The regulated voltage can be used to run the
internal logic of the HV832. The amount of current necessary to
run the internal logic is 150µA Max at a V
the regulated voltage could easily provide the current without
being loaded down.
of 3.0V . Therefore,
DD
x IIN), will also increase. If the input power is greater than the power
IN
Figure 2: Split Supply
egulated Voltage=
Logic Input Puls
Battery Voltage=
ontro
N
HV832M
EL Lamp
EL Lamp 2
o
S
S
12/13/01rev.8
1235 Bordeaux Drive, Sunnyvale, CA 94089
©2001 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited.
6
TEL: (408) 744-0100 • FAX: (408) 222-4895
www.supertex.com
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