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FEATURES
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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
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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
POWER RATING
8-PIN TO-3
PACKAGE STYLE CE
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.
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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APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
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APEX [ CIRRUS LOGIC ]
