Simplification of transfer function in switching converter with general load impedance

Abstract

Conventionally the small-signal characteristics of switching DC-DC converters have usually been analyzed on the assumption that the load is a pure resistance mainly for analytical simplicity. However, in many cases an actual load is not necessarily a pure resistance. This paper presents a simplified transfer function of duty ratio to output voltage of the forward switching converter with a general load impedance by introducing some assumptions which are usually satisfied. The validity of the simplified transfer function is confirmed by comparing computer-calculated results with experimental data. This approach is applied to some other switching converter topologies.<>