P r o d u c t
PA82J
PA81J,
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PA81J • PA82J
PA81J • PA82J
High Voltage Power Operational Amplifiers
FEATURES
• HIGH VOLTAGE OPERATION — ±150V (PA82J)
• HIGH OUTPUT CURRENT — ±30mA (PA81J)
• LOW BIAS CURRENT, LOW NOISE — FET Input
APPLICATIONS
• HIGH IMPEDANCE BUFFERS UP TO ±140V
• ELECTROSTATIC TRANSDUCER & DEFLECTION
• PROGRAMMABLE POWER SUPPLIES TO ±145V
• BIOCHEMISTRY STIMULATORS
• COMPUTER TO VACUUM TUBE INTERFACE
+75V
8-PIN TO-3
PACKAGE STYLE CE
70K
DESCRIPTION
The PA80 series of high voltage operation amplifiers provides
an extremely wide range of supply capability with two over-
lapping products. High accuracy is achieved with a cascode
input circuit configuration. All internal biasing is referenced
to a zener diode. As a result, these models offer outstanding
common mode and power supply rejection. The output stage
operates in the class A/B mode for best linearity. Internal phase
compensation assures stability at all gain settings without ex-
ternal components. Fixed internal current limits protect these
amplifiers against a short circuit to common at most supply
voltages. For sustained high energy flyback, external fast
recovery diodes should be used. However, a heatsink may
be necessary to maintain the proper case temperature under
normal operating conditions.
This hybrid circuit utilizes thick film resistors, ceramic
capacitors and silicon semiconductors to maximize reliabil-
ity, minimize size and give top performance. Ultrasonically
bonded aluminum wires provide reliable interconnections
at all operating temperatures. The 8-pin TO-3 package (see
Package Outlines) is hermetically sealed and isolated from
the internal circuits. The use of compressible thermal washers
voids the warranty.
±1mA
D/A
.47
PA81J
±70V
.47
–75V
HIGH VOLTAGE PROGRAMMABLE POWER SUPPLY
TYPICAL APPLICATION
The PA81 and 70K ohm resistor form a current to voltage
converter, accepting ±1mA from a 12 bit current output digital
to analog converter. The power op amp contribution to the er-
ror budget is insignificant. At a case temperature of 70°C, the
combination of voltage offset and bias errors amounts to less
than 31ppm of full scale range. Incorporation of the optional
offset trim can further reduce these errors to under 9ppm.
EQUIVALENT SCHEMATIC
4
2
EXTERNAL CONNECTIONS
BAL
BAL
–IN
4
C1
3
D1
Q1
Q2
Q4
Q5
C2
Q8
Q9
C4
Q12A
Q13
Q14
Q16
Q15
C6
D2
Q17
Q12B
Q11
1
+V
S
3
Q3
2
1
OUTPUT
TOP VIEW
5
6
8
7
C3
Q7
Q6
C5
5
+IN
–V
S
N.C.
NOTE: Input offset trimpot optional.
Recommended value of 100KΩ
6
7
PA81-82U
http://www.cirrus.com
Copyright © Cirrus Logic, Inc. 2009
(All Rights Reserved)
MAY 2009
1
APEX − PA81-82JUREVJ
CIRRUS [ CIRRUS LOGIC ]
