Method and apparatus for modifying right half-plane zero in a cascaded DC-DC buck-boost converter

摘要

A method to generate a substantially DC output having a voltage level different than a DC input, constituted of receiving a feedback signal representing at least one of the voltage level and the current level of the generated substantially DC output; relatively emphasizing the high frequency portion of the feedback signal; controlling the buck function of a cascaded buck-boost converter with a first switching signal having a first duty cycle, the first duty cycle being a first function of the received feedback signal responsive to said relatively emphasized high frequency portion; and controlling the boost function with a second switching signal having a second duty cycle, the second duty cycle being a second function of the received feedback signal, wherein the first switching signal and the second switching signal are continuously enabled to facilitate a continuous conduction mode.