INPUT CURRENT COMPENSATION FOR TRANSISTOR OPERATIONAL AMPLIFIERS

Abstract

The input current of transistor operational amplifiers limits their application for some uses. Several techniques are described which result in a substantial reduction of this input current. The resulting input current can range from 20% of the original current over a wide temperature span. The percentage reduction depends on the degree of complexity and precision of the compensating circuit used. One type of compensation uses a thermistor-resistor circuit. This technique is developed in detail--both analytically and experimentally, and various examples are given. For the case of a transistor having an input current of 50 nA, it is possible to design circuits to reduce this value to as little as 0.5 nA over a 50C temperature span.

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Document Details

Document Type
Technical Report
Publication Date
Oct 28, 1964
Accession Number
AD0608819

Entities

People

  • J. N. Harris
  • R. S. Orr

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Amplifiers
  • Carbides
  • Circuit Analysis
  • Circuits
  • Coefficients
  • Compensation
  • Detectors
  • Electronics Laboratories
  • Low Temperature
  • Measurement
  • Operational Amplifiers
  • Power Electronics
  • Semiconductors
  • Silicon Carbide
  • Temperature Control
  • Temperature Gradients
  • Thermistors

Fields of Study

  • Physics

Readers

  • Computational Modeling and Simulation
  • Electrical Engineering
  • Thermal Physics or Thermal Science.