The Cause and Eliminate Method of Self-excited Oscillation in Long Cable Amplifier Circuits

SMA long cable distributed capacitance is easy to trigger broadband amplifier circuit’s self-oscillation. In this study we design an amplifier circuit based on OPA691 chip, discuss the influence of long cable’s distributed capacitance, then prompt a solution to add 50Ω compensation resistor between...

Full description

Saved in:
Bibliographic Details
Published in:MATEC web of conferences 2018-01, Vol.173, p.2032
Main Authors: Wang, Can, Huang, Ming, Peng, Zhaomin, Cui, Jinbao
Format: Article
Language:English
Subjects:
Amplifier design
Broadband amplifiers
Capacitance
Circuit design
Compensation
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:SMA long cable distributed capacitance is easy to trigger broadband amplifier circuit’s self-oscillation. In this study we design an amplifier circuit based on OPA691 chip, discuss the influence of long cable’s distributed capacitance, then prompt a solution to add 50Ω compensation resistor between the output terminal and the load capacitance. According to the Tina simulation analysis, when 50Ω compensation resistor is added, bode diagrams show amplitude characteristic is smaller than 0 dB at -180 ° phase. The selfoscillation also disappeared in actual circuit measurement, which verify the rationality of this solution.
ISSN:2261-236X
2274-7214
2261-236X
DOI:10.1051/matecconf/201817302032