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PA51 • PA51A
PA51 • PA51A
Power Operational Amplifier
FEATURES
• WIDE SUPPLY RANGE — ±10 to ±40V
• HIGH OUTPUT CURRENT — ±10A Peak
• CLASS “C” OUTPUT — Low Cost
• LOW QUIESCENT CURRENT — 2.6mA
APPLICATIONS
• DC SERVO AMPLIFIER
• MOTOR/SYNCHRO DRIVER
• VALVE AND ACTUATOR CONTROL
• DC OR AC POWER REGULATOR
8-PIN TO-3
PACKAGE STYLE CE
TYPICAL APPLICATION
C1
DESCRIPTION
The PA51 and PA51A are high voltage, high output current
operational amplifiers designed to drive resistive, inductive and
capacitive loads.Their complementary common emitter output
stage is the simple class C type optimized for low frequency
applications where crossover distortion is not critical. These
amplifiers are not recommended for audio, transducer or deflec-
tion coil drive circuits. The safe operating area (SOA) is fully
specified and can be observed for all operating conditions by
selection of user programmable current limiting resistors. Both
amplifiers are internally compensated for all gain settings. For
continuous operation under load, mounting on a heatsink of
proper rating is recommended. Do not use isolation washers!
This hybrid integrated circuit utilizes thick film conductors,
ceramic capacitors and semiconductor chips to maximize reli-
ability, minimize size and give top performance. Ultrasonically
bonded aluminum wires provide reliable interconnections at
all operating temperatures. The 8-pin TO-3 package is electri-
cally isolated and hermetically sealed. The use of compress-
ible thermal washers and/or improper mounting torque will
void the product warranty. Please see “General Operating
Considerations”
.
+10V
0/+5V
DAC
R1
4.16K
R2
2.5K
–28V
R3
.1Ω
PA51
R4
.1Ω
0/6A
M
MOTOR CURRENT IS A FUNCTION OF V
IN
PROGRAMMABLE TORQUE CIRCUIT
R5
.5Ω
The linear relationship of torque output to current input of
the modern torque motor makes this simple control circuit
ideal for many material processing and testing applications.
The sense resistor develops a feedback voltage proportional
to motor current and the small signal properties of the Power
Op Amp insure accuracy. With this closed loop operation, tem-
perature induced impedance variations of the motor winding
are automatically compensated.
EQUIVALENT SCHEMATIC
3
Q1A
EXTERNAL CONNECTIONS
+V
S
3
CL+
2
1
R
CL+
OUT
OUTPUT
Q1B
2
+IN
4
TOP VIEW
–IN
5
6
7
8
CL–
Q3
4
A1
5
Q4
C1
Q6B
8
Q6A
6
1
R
CL–
–V
S
N.C.
PA51U
http://www.cirrus.com
Copyright © Cirrus Logic, Inc. 2009
(All Rights Reserved)
MAY 2009
1
APEX − PA51UREVR
CIRRUS [ CIRRUS LOGIC ]
