Input filter design for current-programmed regulators

The design of input filters for switched-mode regulators is discussed, and it is shown that the filter's effect on the power system depends on the control method used in the regulator's DC-DC converter. Design inequalities are reviewed for duty-ratio programmed converters, and specific expressions are presented for current-programmed converters. Examples of application to practical regulator circuits are given, where current-programmed criteria, computer-driven measurement tools, and numerical evaluations of analytic expressions are used to design input filters from laboratory data or from specified black box parameters. >