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FEATURES
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1140V P-P SIGNAL OUTPUT
WIDE SUPPLY RANGE — ±75V to ±600V
PROGRAMMABLE CURRENT LIMIT
75 mA CONTINUOUS OUTPUT CURRENT
HERMETIC SEALED PACKAGE
INPUT PROTECTION
PATENTED
APPLICATIONS
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PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC DEFLECTION
SEMICONDUCTOR TESTING
TYPICAL APPLICATION
HIGH VOLTAGE MO-127
PACKAGE STYLE DC
DESCRIPTION
The PA89 is an ultra high voltage, MOSFET operational
amplifier designed for output currents up to 75 mA. Output
voltages can swing over 1000V p-p. 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 and 120dB open loop gain.
All internal biasing is referenced to a bootstrapped zener-
MOSFET current source, giving the PA89 a wide supply range
and excellent supply rejection. The MOSFET output stage is
biased for class A/B linear operation. External compensation
provides user flexibility. The PA89 is 100% gross leak tested
to military standards for long term reliability.
This hybrid integrated circuit utilizes a beryllia (BeO) sub-
strate, thick film resistors, ceramic capacitors and semiconduc-
tor chips to maximize reliability, minimize size and give top
performance. Ultrasonically bonded aluminum wires provide
reliable interconnections at all operating temperatures. The
MO-127 High Voltage, Power Dip™ package is hermetically
sealed and electrically isolated. The use of compressible
thermal washers will void the product warranty.
Ultra-high voltage capability combined with the bridge ampli-
fier configuration makes it possible to develop +/–1000 volt
peak swings across a piezo element. A high gain of –50 for
A1 insures stability with the capacitive load, while “noise-gain”
compensation Rn and Cn on A2 insure the stability of A2 by
operating in a noise gain of 50.
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EXTERNAL CONNECTIONS
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PHASE COMPENSATION
Gain
1
10
15
100
C
C
470pF
68pF
33pF
15pF
R
C
470Ω
220Ω
220Ω
220Ω
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Note: C
C
must be rated for full supply voltage –Vs to +Vs.
See details under “EXTERNAL COMPONENTS”.
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
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