HV257_13 Datasheet, PDF (1/15 Pages) Supertex, Inc – 32-Channel High Voltage Sample and Hold Amplifier Array

Supertex inc.
HV257
32-Channel High Voltage
Sample and Hold Amplifier Array
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
Applications
►► MEMS (microelectromechanical systems)
driver
►► Piezoelectric transducer driver
►► Optical crosspoint switches (using MEMS
technology)
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, V_SIG.
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 0 to 4.096V. The
input voltage can be up to 5.0V, but the output will saturate. The
maximum output voltage swing is 5.0V 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.
Typical Application Circuit
DAC
Micro
Processor
HV257
High Voltage
Power Supply
VSIG
Low Voltage
Power Supply
A0
A1
32
Low Voltage
A2
Channel
A3
Select
Sample
A4
and Hold
EN
High
Voltage
OpAmp
Array
HV_OUT0
HV_OUT1
HV_OUT2
HV_OUT3
HV_OUT30
HV_OUT31
DGND
AGND
VNN
y
x
x
y
MEMS
Array
Doc.# DSFP-HV257
D070813
Supertex inc.
www.supertex.com