| 摘要 |
PROBLEM TO BE SOLVED: To obtain a buck-boost DC-DC converter which can perform a buck-boost operation certainly even for an overlap period of each triangular wave of a first triangular wave for performing voltage fall control with a second triangular wave for performing voltage rise control, and can attain the stabilization of an output voltage. SOLUTION: The value of the second voltage V2 outputted from a first constant voltage source 23 is set so that overlap periods T1 and T2 of the first triangular wave TW1 and the second triangular wave TW2 become longer than each delay time of a voltage fall side comparing circuit CMP1 and a voltage rise side comparing circuit CMP2. Consequently, the buck-boost operation of the output voltage Vout can be performed certainly even during the overlap periods T1 and T2 of the first triangular wave TW1 and the second triangular wave TW2. COPYRIGHT: (C)2006,JPO&NCIPI
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