Precise regulation of multiple output voltages in a dc-dc converter

A new dc-dc converter is presented to perform the precise regulation of multiple output voltages, which is composed of the cascade connection circuit of the improved forward type multiple-output converter and the step-down type single-output converters. In the conventional multiple-output converter using cross regulation, the steady-state errors in the cross regulated outputs cannot be made smaller than some values for the change of the load even if the proportional gain of the feedback controller is increased. Also, in the multiple-output converters with additional switches, which are connected in series with the diode rectifiers in each cross regulated output unit, it is difficult to perform the precise regulation of multiple outputs for the large change of each load. On the other hand, by the method presented here, the satisfactory regulation performance can be achieved easily for the conditions of no load to full load. The steady-state and the dynamic characteristics are clarified through the equivalent circuits, and also it is demonstrated experimentally that this converter has a sufficiently high conversion efficiency.