Small-Signal Analysis of a Coupled-Inductor Step-Down Switching DC-DC Converter

Small-signal model of an unfamiliar step-down switching dc-dc converter with continuous input and output current is derived. As a result, analytical expression for the control-to-output transmittance having two zeros and four poles is obtained. An interesting feasibility of the effective zero-pole cancelation is shown which leads to the simple second-order frequency response. Applicability of the standlarized control module for optimization of the overall closed-loop frequency characteristics is discussed.