Dc-dc converter switched noise filter circuit for

Switched noise filter circuit for DC-DC converter for setting the duty ratio of the converter by using the instantaneous output voltage. This converter, respectively, to periodically on and off the switching element over a time interval T The switching control circuit (40) includes a connected filter capacitance between ground terminals the feedback node (42) (Cf), a comparator (A1) for comparing a feedback voltage At least one of T Switched noise filter circuit (46) applies an offset voltage to V When this offset voltage is properly applied, the influence of electromagnetic noise extraneous coupled to V