A Novel AC-Amplifier for Electrophysiology: Active DC Suppression With Differential to Differential Amplifier in the Feedback-Loop

Abstract

A novel AC amplifier for electrophysiological measurements that uses three op-amps based instrumentation amplifier (IA), and active suppression of the input offset was designed. The development followed the requirements to increase the common mode rejection ratio, thereby allow the recordings of physiological signals in a noisy environment. In the proposed circuit the high common-mode rejection ratio was achieved by using a high gain at the first stage of the IA (60 dB) and no passive components at the inputs. The feedback was achieved by means of a differential to differential amplifier placed in the input loop. This configuration provides an active suppression of DC-offset by feeding back an integrated form of the output that is equal to the input, yet of the opposite sign. an The SPICE simulation of the novel amplifier with a gain of 80 dB and a high-pass cutoff frequency at 100 mHz are presented in this paper.

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Document Details

Document Type
Technical Report
Publication Date
Oct 25, 2001
Accession Number
ADA412379

Entities

People

  • Dosen Strahinja
  • Jorgovanovic Nikola
  • Petrovic Ratko
  • Popovic B. Dejan

Organizations

  • University of Novi Sad

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Abstracts
  • Amplifiers
  • Amplitude
  • Base Lines
  • Circuits
  • Couplings
  • Engineering
  • Feedback
  • Frequency
  • Gain
  • High Gain
  • Impedance
  • Instrumentation
  • Integrators
  • Military Research
  • Power Supplies
  • Simulations

Readers

  • Acoustics.
  • Electronics Engineering
  • Integrated Circuit Design and Technology.