Extending the frequency range of a Wien-bridge oscillator using composite operational amplifiers

The author describes the use of composite operational amplifiers to extend the useful operating frequency range of an operational amplifier-based Wien-bridge oscillator. The effect of the finite gain-bandwidth product (GB) of the operational amplifier (OA) is analyzed. This analysis shows that for a...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on instrumentation and measurement 1989-06, Vol.38 (3), p.740-744
Main Author: Awad, S.S.
Format: Article
Language:English
Subjects:
Applied sciences
Bandwidth
Circuit properties
Circuits
Distortion measurement
Electric, optical and optoelectronic circuits
Electronic circuits
Electronics
Exact sciences and technology
Frequency
Impedance
Operational amplifiers
Oscillators
Oscillators, resonators, synthetizers
Resistors
Temperature
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The author describes the use of composite operational amplifiers to extend the useful operating frequency range of an operational amplifier-based Wien-bridge oscillator. The effect of the finite gain-bandwidth product (GB) of the operational amplifier (OA) is analyzed. This analysis shows that for a certain GB the frequency of oscillation is less than the theoretical value and that the error increases with frequency. A composite OA is then used to decrease the errors due to GB. This is verified theoretically and experimentally. Although the composite OA improves the frequency performance of the oscillator, the amplitude of the output decreases with frequency. An automatic-gain control circuit is incorporated to keep an output amplitude constant over the useful frequency range. Distortion measurements are presented.< >
ISSN:0018-9456
1557-9662
DOI:10.1109/19.32184