High Voltage Amplifier Array
HV256DB1
Introduction
The Supertex HV256DB1 is a 32-Channel 295V
amplifier array with a nominal gain of 72V/V. The
purpose of the HV256DB1 is to provide a means to
easily evaluate the Supertex HV256FG device. A high
voltage supply, V
PP
, and two low voltage supplies, V
DD
and V
NN
, are required. These connections can be made
via the J1 header provided on the board. There are 32
pads on the left side of the board for the input signals
and 32 pads on the right for the outputs. Be sure to
follow the power up/down sequence to avoid damaging
the device.
Specifications
V
PP
, High voltage supply
V
DD
, Low voltage positive supply
V
NN
, Low voltage negative supply
V
IN
, Input signal range
HV
OUT
, Output voltage swing
Av, Closed loop gain
SR, Output slew rate into 100pF load
300V
6.0V to 7.5V
-4.5V to -6.5V
0V to 5.0V
0V to 295V
72V/V ±5%
2.0V/µs
Demo Board Layout
Power Supply Inputs
D2
J1
D1
C1
C2
C3
32 Inputs
U1
32 Outputs
C4 C5
R1
R2 C6
Power Up/Down Sequence
The device can be damaged due to improper power
up/down sequence. To prevent damage, please follow
the acceptable power up/down sequences. Two external
diodes, D1 and D2, are added in the demo board to
prevent damage during power Up/Down. The first diode
is a high voltage diode across V
PP
and V
DD
. Any low
current high voltage diode can be used. The second
diode can be any low voltage schottky diode across V
NN
and Gnd.
Acceptable Power Up Sequences
1) V
PP
2) V
NN
3) V
DD
4) Inputs & Anode
or
Inputs and Outputs
The output of the HV256FG will swing from 0V to 295V.
The internal closed loop gain is set at 72V/V. An input
voltage of 4.096V will give an output of 295V. Input
voltages of up to 5V can be applied but will cause the
amplifier to saturate.
The output current source and sink for all 32 channels
can be adjusted using R1 and R2. The limit is
approximately 12.5V divided by the resistor value. The
demo board uses 24.9Kohm for ±500uA limiting.
Temperature Diode
The HV256FG has an integrated silicon diode to help
monitor the die temperature if desired. Pin 37 is the
anode and pin 36 is the cathode. Pads are available on
the board for these connections.
1) V
NN
2) V
DD
3) V
PP
4) Inputs & Anode
Acceptable Power Down Sequences
1) Inputs & Anode
2) V
DD
3) V
NN
4) V
PP
or
1) Inputs & Anode
2) V
PP
3) V
DD
4) V
NN
A071404
Supertex, Inc.
•
1235 Bordeaux Drive, Sunnyvale, CA 94089
•
Tel: (408) 222-8888
•
FAX: (408) 222-4895
•
www.supertex.com
SUPERTEX [ Supertex, Inc ]
