Small-Signal Transfer-Function Extraction of a Lossy Buck Converter Using ASM Technique

Abstract: Nowadays, step-down power converters such as buck scheme are widely employed in a variety of applications such as power supplies, spacecraft power systems, hybrid vehicles and DC motor drives. This paper determines the small signal averaged switch model (ASM) of the buck converter with parasitic elements consideration. Lossy analysis helps one to better understanding of the time-frequency domain behaviour and accurate designing the feedback control circuitry. After determining the control-to-output and audio-successability transfer functions, finally the proposed model results are validated by simulations in PSpice and Matlab software.

Keywords: Buck Converter, Parasitic Elements, Small-Signal Transfer-Function, Averaged Switch Model.