PA12 • PA12A

PA12U

1

PA12, PA12A

FEATURES

•LOWTHERMALRESISTANCE—1.4°C/W

•CURRENTFOLDOVERPROTECTION—NEW

•HIGHTEMPERATUREVERSION—PA12H

•EXCELLENTLINEARITY—ClassA/BOutput

•WIDESUPPLYRANGE—±10Vto±50V

•HIGHOUTPUTCURRENT—Upto±15APeak

APPLICATIONS

•MOTOR,VALVEANDACTUATORCONTROL

•MAGNETICDEFLECTIONCIRCUITSUPTO10A

•POWERTRANSDUCERSUPTO100kHz

•TEMPERATURECONTROLUPTO360W

•PROGRAMMABLEPOWERSUPPLIESUPTO90V

•AUDIOAMPLIFIERSUPTO120WRMS

DESCRIPTION

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

current operational amplifier designed to drive resistive, induc-

tive 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 operation 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.

EQUIVALENTSCHEMATIC

3

4

5

6

2

1

8

A1

D1

Q1

Q4

Q3

Q5

C1

Q2A

Q2B

Q6B

Q6A

7

POWERRATING

Not all vendors use the same method to rate the power

handling capability of a Power Op Amp.Apex Microtechnology

rates the internal dissipation, which is consistent with rating

methods used by transistor manufacturers and gives conser-

vative 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.

THERMALSTABILITY

Apex Microtechnology 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 Microtech-

nology in 1981 using thermistors which assure a negative

temperature coefficient in the quiescent current.The reliability

benefits of this added circuitry far outweigh the slight increase

in component count.

EXTERNALCONNECTIONS

8-PINTO-3

PACKAGESTYLECE

Power Operational Amplifier

PA12 • PA12A

CL+

+V

S

+IN

–IN

–V

S

F.O.

CL–

OUT

TOP VIEW

R

CL+

R

CL-

OUTPUT

1

2

3

4

5

6

7

8

Copyright © Apex Microtechnology, Inc. 2012

(All Rights Reserved)

www.apexanalog.com

OCT 2012

PA12U REVV