A new methodology aiming for enhancement of power supplies design evaluation for light-load efficiency improving based on loop-gain analytical technique

A methodology, utilizing loop gain of circuitry to extract the main features for providing the useful indexes being able to come out the evaluation of light-load operation efficiency for power supply design, is proposed herein. A DC-to-DC converter scheme for adaptor application is adopted for demonstrating the relation between switching device conduction duty cycle ratio, loop gain, and efficiency improving at light load operation through skipping cycle setting and implementation. Analysis for figuring out gradient based on loop gain to duty tuning is taken into account and the succeeding derivation is verified to be the important factor for instructing the related circuit parameter selection among gain of feedback control loop and the open-loop control gain in an efficient way with referable criteria. The design flowchart followed and the effectiveness demonstrated applying the presented analysis are both provided through a comparison from the output of the proposed indexes.