Power losses and efficiency of buck PWM DC-DC power converter

This paper derives an expression for efficiency of the buck converter that is obtained by determining the power loss in each component of a power converter. The expression for efficiency is derived as a function of the DC voltage transfer function and the circuit parameters. For a selected design, the derived expression is validated using a PSpice simulation. The expression is used to predict the variation in efficiency as well as the duty cycle of the design for two conditions: with varying input voltage and a fixed load; and with a fixed input voltage and a varying load