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

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FEATURES

• HIGH VOLTAGE — 450V (±225V)

• HIGH SLEW RATE — 1000V/μS

• HIGH OUTPUT CURRENT — 200mA

APPLICATIONS

• HIGH VOLTAGE INSTRUMENTATION

• PIEZO TRANSDUCER EXCITATION

• PROGRAMMABLE POWER SUPPLIES UP TO 430V

• ELECTROSTATIC TRANSDUCERS & DEFLECTION

DESCRIPTION

The PA98 is a high voltage, high power bandwidth MOSFET

operational amplifier designed for output currents up to 200mA.

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 appropri-

ate 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 PA98 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 thick film (cermet) resistors, ceramic

capacitors and silicon semiconductor chips to maximize reli-

ability, minimize size and give top performance. Ultrasonically

bonded aluminum wires provide reliable interconnections at

all operating temperatures. The Power SIP package is electri-

cally isolated.

EQUIVALENT SCHEMATIC

TYPICAL APPLICATION

DYNAMIC FOCUSING

Dynamic focusing is the active correction of focusing voltage

as a beam traverses the face of a CRT. This is necessary in

high resolution flat face monitors since the distance between

cathode and screen varies as the beam moves from the center

of the screen to the edges. PA98 lends itself well to this function

since it can be connected as a summing amplifier with inputs

from the nominal focus potential and the dynamic correction.

The nominal might be derived from a potentiometer, or per-

haps automatic focusing circuitry might be used to generate

this potential. The dynamic correction is generated from the

sweep voltages by calculating the distance of the beam from

the center of the display.

EXTERNAL CONNECTIONS

PHASE COMPENSATION

Gain

C

C

R

C

1

68pF

100Ω

20

10pF

330Ω

100

3.3pF

0Ω

C

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PATENTED

12-PIN SIP

PACKAGE STYLE DP

Formed leads available

Package styles ED & EE