| US 7,468,898 B2 | ||
| DC-DC converter with switchable capacitors | ||
| Takashige Ogata, Gunma (Japan); and Tatsuya Suzuki, Saitama-ken (Japan) | ||
| Assigned to Sanyo Electric Co., Ltd., Osaka (Japan) | ||
| Filed on Jul. 28, 2005, as Appl. No. 11/191,242. | ||
| Claims priority of application No. 2004-221437 (JP), filed on Jul. 29, 2004. | ||
| Prior Publication US 2006/0028849 A1, Feb. 09, 2006 | ||
| Int. Cl. H02M 3/18 (2006.01); H02M 7/00 (2006.01); H02M 7/19 (2006.01) | ||
| U.S. Cl. 363—59 [363/60; 307/110; 307/109] | 12 Claims |
| 1. A DC-DC converter comprising:
a plurality of switchable capacitors including a first capacitor and a second capacitor;
an output terminal;
a switching circuit that connects the plurality of switchable capacitors in parallel with each other between the output terminal
and a ground voltage in a first phase and connects the plurality of switchable capacitors in series with each other between
the output terminal and an input voltage in a second phase, and
an output capacitor,
wherein the output capacitor is provided between the output terminal and the ground voltage,
wherein the output terminal is electrically connected with the plurality of switchable capacitors in the first and second
phases,
wherein the switching circuit comprises a first switch provided between an input terminal to which the input voltage is applied
and a first end of the first capacitor, a second switch provided between a second end of the first capacitor and the ground
voltage, a third switch provided between a first end of the second capacitor and the output terminal from which an output
voltage is obtained and a fourth switch provided between a second end of the second capacitor and the output terminal, and
wherein, in the first phase, the output capacitor is discharged and the plurality of switchable capacitors are charged, and
in the second phase, the output capacitor is charged and the plurality of switchable capacitors are discharged.
|