Unterminated Small-Signal Behavioral Model of DC–DC Converters

The “black-box” modeling of dc–dc converters has always been an attractive topic widely used in engineering practice. However, in order to obtain unterminated model of dc–dc converter, the one had to be removed from the original environment and connected to the high-bandwidth voltage source and current sink for easier decoupling of the source and the load dynamics. This paper addresses an online dc–dc converter characterization procedure where converter under test can remain working in the original environment, at the particular operating point, and be connected to any type of the source and the load while the terminated frequency response characteristics are obtained. The source and the load dynamics can then be decoupled from the measured frequency responses using here proposed linear transformation matrix. The verification and validation of the proposed technique will be both presented in this paper.