APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com

1

EXTERNAL CONNECTIONS

TYPICAL APPLICATION

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.

��

����

��

����

�

���

�����

�����

����������

���

�

�����

�����

�����

�����������������������������

���

��

PATENTED

PHASE COMPENSATION

Gain

C

C

R

C

1

470pF

470Ω

10

68pF

220Ω

15

33pF

220Ω

100

15pF

220Ω

Note: C

See details under “EXTERNAL COMPONENTS”.

���

����

���

���

���

���

�����

��������

��������

������������������

������������������

��

���

�

�

������

��

�������

��

��

�

�

�

�

�

�

��

��

��

�

�

�

���

����

FEATURES

• 1140V P-P SIGNAL OUTPUT

• WIDE SUPPLY RANGE — ±75V to ±600V

• PROGRAMMABLE CURRENT LIMIT

• 75 mA CONTINUOUS OUTPUT CURRENT

• HERMETIC SEALED PACKAGE

• INPUT PROTECTION

APPLICATIONS

• PIEZOELECTRIC POSITIONING

• HIGH VOLTAGE INSTRUMENTATION

• ELECTROSTATIC DEFLECTION

• SEMICONDUCTOR TESTING

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.

SIMPLIFIED SCHEMATIC

�

�

�

�

�

�

��

�

���

���

����

�

���

���

���

�

��

��

��

���

���

���

���

���

����

����

���

���

���

���

���

��

���

���

���

���

���

��

��������������������������������������������������������������

� � � � � � � � � � � � � � �

�����������������������������������������

������������

HIGH VOLTAGE MO-127

PACKAGE STYLE DC