PA83A - High Voltage Power Operational Amplifier, 300V, .075mA, "A" Grade
The PA83 is a high voltage operational amplifier designed for output voltage swings up to ±145V with a dual (±) 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 excellent 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 semiconductor chips to maximize reliability, minimize size and give top performance. Ultrasonically bonded aluminum wires provide 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.
While piezo electric transducers present a complex impedance, 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.
• LOW BIAS CURRENT, LOW NOISE — FET Input
• FULLY PROTECTED INPUT — Up to ±150V
• WIDE SUPPLY RANGE — ±15V to ±150V
• HIGH VOLTAGE INSTRUMENTATION
• ELECTROSTATIC TRANSDUCERS & DEFLECTION
• PROGRAMMABLE POWER SUPPLIES UP TO 290V
• ANALOG SIMULATORS
- APEX Microtechnology product -