Time-varying effects in models for current-mode control

This paper investigates issues in modeling of current-mode controlled DC-DC converters. The effects of the current-sampling intrinsic to current-mode control are analyzed, and inadequately recognized limitations of linear, time invariant models at high frequencies are exposed. The paper also examines the geometric methods used to derive duty ratio constraints in averaged models of current-mode control. The conclusions are supported by simulation and experimental results.<>