Patent ID: 8957650
Filing Date: 2015-02-17
Classification: H02M

Abstract:
1. A switching control circuit generating and outputting on/off signals of a first switching device supplying a current to a voltage conversion inductor of a step-up/down DC-DC converter and a second switching device receiving the current from the inductor, the switching control circuit comprising: an error amplifier circuit outputting a voltage corresponding to an output voltage of the DC-DC converter; an inverting amplifier circuit inverting the output from the error amplifier circuit with reference to a predetermined voltage; a waveform generator circuit generating triangle waves; a first voltage comparator circuit receiving the output from the error amplifier circuit and an output from the waveform generator circuit; a second voltage comparator circuit receiving an output from the inverting amplifier circuit and the output from the waveform generator circuit; and a peak-value detector circuit detecting a peak value of the triangle waves generated at the waveform generator circuit and supplying a voltage corresponding to the peak value to the inverting amplifier circuit as a reference voltage, wherein the peak-value detector circuit includes a voltage averaging circuit extracting an average voltage of the triangle waves generated at the waveform generator circuit and a multiplying circuit amplifying the voltage extracted by the voltage averaging circuit by a predetermined factor.