鈥?HIGH OUTPUT CURRENT 鈥?/div>
鹵30mA
(PA81J)
鈥?LOW BIAS CURRENT, LOW NOISE 鈥?FET Input
APPLICATIONS
鈥?HIGH IMPEDANCE BUFFERS UP TO
鹵140V
鈥?ELECTROSTATIC TRANSDUCER & DEFLECTION
鈥?PROGRAMMABLE POWER SUPPLIES TO
鹵145V
鈥?BIOCHEMISTRY STIMULATORS
鈥?COMPUTER TO VACUUM TUBE INTERFACE
70K
+75V
鹵1mA
D/A
DESCRIPTION
The PA80 series of high voltage operation amplifiers pro-
vides an extremely wide range of supply capability with two
overlapping 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 external 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 ca-
pacitors and silicon semiconductors to maximize reliability,
minimize size and give top performance. Ultrasonically bonded
aluminum wires provide reliable interconnections at all operat-
ing 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.
.47
PA81J
鹵70V
.47
鈥?5V
HIGH VOLTAGE PROGRAMMABLE POWER SUPPLY
TYPICAL APPLICATION
The PA81 and 70K ohm resistor form a current to voltage
converter, accepting
鹵1mA
from a 12 bit current output digital
to analog converter. The power op amp contribution to the
error budget is insignificant. At a case temperature of 70擄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
+V
S
3
2
1
4
C1
D1
3
BAL
BAL
鈥揑N
Q3
Q1
Q2
Q4
Q5
C3
Q6
Q9
C4
Q12A
Q13
Q14
Q16
Q15
C6
D2
Q17
Q11
Q12B
1
OUTPUT
C2
Q8
TOP VIEW
5
6
8
7
C5
5
Q7
+IN
N.C.
鈥揤
S
NOTE: Input offset trimpot optional.
Recommended value of 100K
鈩?/div>
.
6
7
APEX MICROTECHNOLOGY CORPORATION
鈥?TELEPHONE (520) 690-8600 鈥?FAX (520) 888-3329 鈥?ORDERS (520) 690-8601 鈥?EMAIL prodlit@apexmicrotech.com
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