| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a step-up/down DC-DC converter for improving the efficiency of power by reducing switching loss during a shifting period of switching between step-up and step-down. <P>SOLUTION: A switching control circuit includes: an error amplifier circuit (21) for output of a voltage corresponding to an output voltage of the DC-DC converter; an inverting amplifier circuit (22) for inverting the output of the error amplifier circuit while using a predetermined voltage as a reference; a waveform generating circuit (23) for generating a triangular wave; a first voltage comparison circuit (25) for receiving the output of the error amplifier circuit and the output of the waveform generating circuit, which are input; a second voltage comparison circuit (26) for receiving the output of the inverting amplifier circuit and the output of the waveform generating circuit, which are input; and a voltage generating circuit (24) for generating an inverted reference voltage to be supplied to the inverting amplifier circuit. The switching control circuit is configured so that the inverted reference voltage to be supplied to the inverting amplifier circuit is not a potential lower than the highest potential of the triangular wave to be supplied to the voltage comparison circuit. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
