A Method to Improve Switching Power Supply Efficiency at Light Load with DSP Control

Abstract

This paper discusses a digital control method for efficiency improvement of switching power circuit at light load by using C2000 Series DSP (Texas Instruments Inc.). In this work, we alter the module in DSP to adjust the link voltage between a bridgeless PFC AC/DC converter and a phase shift full bridge DC/DC converter, as well as to control the PWM frequency of power circuit in order to improve the power efficiency in a suitable way. Our experiments result show that the efficiency of the power circuit at half or light load improves by adjusting the link voltage and/or PWM frequency