Design of good approximate 2-degree-of-freedom digital controller for robust DC-DC converter

Robust DC-DC converter which can cover extensive load changes and also input voltage changes is needed. In this paper, we propose a method of designing good approximate 2-degree-of freedom (2DOF) digital controller which makes the control bandwidth wider and at the same time makes a variation of the output voltage very small at a sudden change of resistive load. The proposed approximate 2DOF digital controller is actually implemented on a DSP and is connected to a DC-DC converter. Experimental studies demonstrate that this type digital controller can satisfy given specifications.