Loop Instability Caused by 3-Terminal Regulator Decoupling Capacitors

Three-terminal regulator output capacitor selection

A chip is powered by 29302, and the output capacitor is 100uf aluminum electrolytic. Consider connecting six 22uf ceramic capacitors in parallel for fast response. 29302 output sawtooth wave.

Cause Analysis

The three-terminal voltage regulator team has requirements for the output capacitor ESR, and the output capacitor ESR should not be too low. Multiple ceramic capacitors connected in parallel lead to low total ESR of the output capacitors.

ways to improve

Remove excess ceramic capacitors and use tantalum capacitors instead.

Effect

29302 output is normal

postscript

Remember not to use too many ceramic capacitors for decoupling of the three-terminal voltage regulator. Tantalum capacitors can be added if there is a fast response requirement.

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Origin blog.csdn.net/jsf120/article/details/96425731