Investigation of the steady-state and dynamic characteristics of a buck converter with nonlinear output capacitor current programming

Abstract

A detailed steady-state and dynamic analysis of a buck converter with nonlinear output capacitor current programming is presented. The advantages of the proposed method are its constant switching frequency operation, simplicity in implementing the switching functions and designing the control parameters, good steady-state and dynamic responses, and high audio susceptibility rejection. The principle of operation and all possible operating cases will be described and discussed. With the inclusion of the effects of the equivalent series resistance (ESR) of the output capacitor, the steady-state output characteristics and small-signal models for studying the system stability will be derived.An experimental prototype of a 25W, 12V/5V buck converter has been built and evaluated.Index Terms-Predictive Control, buck converter, capacitor current control, dc/dc conversion.

Derivation of a nonlinear output capacitor current programming technique applicable for a buck converter operating in CCM and DCM

“…By putting (36) into (20), 2 t can be calculated as V. STEADY STATE ERROR OF OUTPUT VOLTAGE For the converter operating in CCM, the steady state error of output voltage is calculated in [10]. Fig.…”