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

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FEATURES

• LOW THERMAL RESISTANCE — 1.4°C/W

• CURRENT FOLDOVER PROTECTION — NEW

• HIGH TEMPERATURE VERSION — PA12H

• EXCELLENT LINEARITY — Class A/B Output

• WIDE SUPPLY RANGE — ±10V to ±50V

• HIGH OUTPUT CURRENT — Up to ±15A Peak

APPLICATIONS

• MOTOR, VALVE AND ACTUATOR CONTROL

• MAGNETIC DEFLECTION CIRCUITS UP TO 10A

• POWER TRANSDUCERS UP TO 100kHz

• TEMPERATURE CONTROL UP TO 360W

• PROGRAMMABLE POWER SUPPLIES UP TO 90V

• AUDIO AMPLIFIERS UP TO 120W RMS

DESCRIPTION

The PA12 is a state of the art high voltage, very high

output current operational amplifier designed to drive resis-

tive, inductive and capacitive loads. For optimum linearity,

especially at low levels, the output stage is biased for class

A/B operation using a thermistor compensated base-emitter

voltage multiplier circuit. The safe operating area (SOA) can

be observed for all operating conditions by selection of user

programmable current limiting resistors. For continuous opera-

tion under load, a heatsink of proper rating is recommended.

The PA12 is not recommended for gains below –3 (inverting)

or +4 (non-inverting).

This hybrid integrated circuit utilizes thick film (cermet)

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 isolation washers voids the warranty.

EQUIVALENT SCHEMATIC

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POWER RATING

Not all vendors use the same method to rate the power han-

dling capability of a Power Op Amp. APEX rates the internal

dissipation, which is consistent with rating methods used by

transistor manufacturers and gives conservative results. Rating

delivered power is highly application dependent and therefore

can be misleading. For example, the 125W internal dissipation

rating of the PA12 could be expressed as an output rating of

250W for audio (sine wave) or as 440W if using a single ended

DC load. Please note that all vendors rate maximum power

using an infinite heatsink.

THERMAL STABILITY

APEX has eliminated the tendency of class A/B output

stages toward thermal runaway and thus has vastly increased

amplifier reliability. This feature, not found in most other Power

Op Amps, was pioneered by APEX in 1981 using thermistors

which assure a negative temperature coefficient in the quies-

cent current. The reliability benefits of this added circuitry far

outweigh the slight increase in component count.

EXTERNAL CONNECTIONS

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8-PIN TO-3

PACKAGE STYLE CE