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FEATURES
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HIGH VOLTAGE — 450V (±225V)
LOW QUIESCENT CURRENT — 2mA
HIGH OUTPUT CURRENT — 100mA
PROGRAMMABLE CURRENT LIMIT
LOW BIAS CURRENT — FET Input
PATENTED
APPLICATIONS
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PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC TRANSDUCERS
PROGRAMMABLE POWER SUPPLIES UP TO 440V
8-PIN TO-3
PACKAGE STYLE CE
TYPICAL APPLICATION
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DESCRIPTION
The PA88 is a high voltage, low quiescent current MOS-
FET operational amplifier designed for output currents up to
100mA. Output voltages can swing up to ±215V with a dual
supply and up to +440 volts with a single supply. The safe
operating area (SOA) has no second breakdown limitations
and can be observed with all types of loads by choosing an
appropriate current limiting resistor. High accuracy is achieved
with a cascode input circuit configuration. All internal biasing is
referenced to a bootstrapped zener-MOSFET current source.
As a result, the PA88 features an unprecedented supply range
and excellent supply rejection. The MOSFET output stage is
biased on for linear operation. External compensation provides
user flexibility.
This hybrid circuit utilizes beryllia (BeO) substrates, thick
film resistors, ceramic capacitors and semiconductor chips to
maximize reliability, minimize size and give top performance.
Ultrasonically bonded aluminum wires provide reliable inter-
connections at all operating temperatures. The 8-pin TO-3
package is hermetically sealed and electrically isolated. The
use of compressible thermal isolation washers and/or improper
mounting torque will void the product warranty. Please see
“General Operating Considerations”.
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LOW POWER, PIEZOELECTRIC POSITIONING
Piezo positioning may be applied to the focusing of
segmented mirror systems. The composite mirror may be
composed of hundreds of elements, each requiring focusing
under computer control. In such complex systems the PA88’s
advantage of low quiescent power consumption reduces
the costs of power supplies and cooling, while providing the
interface between the computer and the high voltage drive to
the piezo positioners.
EXTERNAL CONNECTIONS
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APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
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