鈥?WIDE SUPPLY RANGE 鈥?/div>
鹵15V
to
鹵150V
APPLICATIONS
鈥?HIGH VOLTAGE INSTRUMENTATION
鈥?ELECTROSTATIC TRANSDUCERS & DEFLECTION
鈥?PROGRAMMABLE POWER SUPPLIES UP TO 290V
鈥?ANALOG SIMULATORS
100K
+150V
DESCRIPTION
The PA83 is a high voltage operational amplifier designed
for output voltage swings up to
鹵145V
with a dual (鹵) supply or
290V with a single supply. Its input stage is protected against
transient and steady state overvoltages up to and including the
supply rails. High accuracy is achieved with a cascode input
circuit configuration. All internal biasing is referenced to a
zener diode fed by a FET constant current source. As a result,
the PA83 features an unprecedented supply range and excel-
lent supply rejection. The output stage is biased in the class A/
B mode for linear operation. Internal phase compensation
assures stability at all gain settings without need for external
components. Fixed current limits protect these amplifiers
against shorts to common at supply voltages up to 120V. For
operation into inductive loads, two external flyback pulse
protection diodes are recommended. However, a heatsink
may be necessary to maintain the proper case temperature
under normal operating conditions.
This hybrid circuit utilizes beryllia (BeO) substrates, thick
(cermet) film resistors, ceramic capacitors and silicon semi-
conductor chips to maximize reliability, minimize size and give
top performance. Ultrasonically bonded aluminum wires pro-
vide reliable interconnections at all operating temperatures.
The 8-pin TO-3 package is hermetically sealed and electrically
isolated. The use of compressible thermal isolation washers
and/or improper mounting torque voids product warranty.
Please see Application Note 1 鈥淕eneral Operating Consider-
ations鈥?
GATED
OSCILLATOR
3.57K
鹵5V
A1
PA83
鈥?50V
I=
鈭?/div>
V * C
鈭?/div>
t
SIMPLE PIEZO ELECTRIC TRANSDUCER DRIVE
TYPICAL APPLICATION
While piezo electric transducers present a complex imped-
ance, they are often primarily capacitive at useful frequencies.
Due to this capacitance, the speed limitation for a given
transducer/amplifier combination may well stem from limited
current drive rather than power bandwidth restrictions. With its
drive capability of 75mA, the PA83 can drive transducers
having up to 2nF of capacitance at 40kHz at maximum output
voltage. In the event the transducer may be subject to shock
or vibration, flyback diodes, voltage clamps or other protection
networks must be added to protect the amplifier from high
voltages which may be generated.
EQUIVALENT SCHEMATIC
4
2
C1
D1
EXTERNAL CONNECTIONS
+V
S
3
2
1
4
3
Q3
Q1
Q5
Q2
Q4
C3
Q6
Q9
Q10
C4
Q12A
Q13
Q12B
Q11
1
BAL
BAL
鈥揑N
C2
OUTPUT
5
Q8
C5
Q7
TOP VIEW
5
6
8
7
Q14
6
+IN
NOTES:
1. Pin 8 not internally connected.
2. Input offset trimpot optional.
Recommended value 100K
鈩?/div>
.
Q16
Q15
Q17
N.C.
鈥揤
S
C6
7
D2
APEX MICROTECHNOLOGY CORPORATION
鈥?TELEPHONE (520) 690-8600 鈥?FAX (520) 888-3329 鈥?ORDERS (520) 690-8601 鈥?EMAIL prodlit@apexmicrotech.com
Powered by ICminer.com Electronic-Library Service CopyRight 2003
1
2
3
4
