HV257
HV257
Demo Kit
Available
32-Channel High Voltage
Sample and Hold Amplifier Array
General Description
The Supertex HV257 is a 32-channel high voltage sample and
hold amplifier array integrated circuit. It operates on a single high
voltage supply, up to 300V, and two low voltage supplies, V
DD
and V
NN
.
All 32 sample and hold circuits share a common analog input,
Vsig. The individual sample and hold circuits are selected by a
5 to 32 logic decoder. The sampled voltage on the holding
capacitor is buffered by a low voltage amplifier and amplified by
a high voltage amplifier with a closed loop gain of 72V/V. The
internal closed loop gain is set for an input voltage range of 0V
to 4.096V. The input voltage can be up to 5.0V, but the output will
saturate. The maximum output voltage swing is 5V below the V
PP
high voltage supply. The outputs can drive capacitive loads of up
to 3000pF.
The maximum output source and sink current can be adjusted by
using two external resistors. An external R
SOURCE
resistor
controls the maximum sourcing current and an external R
SINK
resistor controls the maximum sinking current. The current limit
is approximately 12.5V divided by the external resistor value.
The setting is common for all 32 outputs. A low voltage silicon
junction diode is made available to help monitor the die
temperature.
Features
❑
32 independent high voltage amplifiers
❑
300V operating voltage
❑
295V output voltage
❑
2.2V/µs typical output slew rate
❑
Adjustable output current source limit
❑
Adjustable output current sink limit
❑
Internal closed loop gain of 72V/V
❑
12MΩ feedback impedance
❑
Layout ideal for die applications
Application
❑
MEMS (microelectromechanical systems) driver
❑
Piezoelectric transducer driver
❑
Optical crosspoint switches (using MEMS technology)
Typical Application
Supertex HV257
DAC
V
SIG
Low Voltage
Power Supply
High Voltage
Power Supply
HV
OUT
0
HV
OUT
1
HV
OUT
2
HV
OUT
3
x
y
y
x
Micro
Processor
A
0
A
1
A
2
A
3
A
4
EN
DGND
32
Low Voltage
Channel
Select
Sample
and Hold
High Voltage
OpAmp Array
MEMS
Array
HV
OUT
30
HV
OUT
31
R
SOURCE
R
SINK
AGND
V
NN
A122104
A122104
1
SUPERTEX [ Supertex, Inc ]
