| US 7,511,564 B2 | ||
| Voltage-booster power supply circuit | ||
| Takashi Tahata, Kanagawa (Japan) | ||
| Assigned to NEC Electronics Corporation, Kawasaki, Kanagawa (Japan) | ||
| Filed on Oct. 18, 2007, as Appl. No. 11/907,897. | ||
| Claims priority of application No. 2006-285968 (JP), filed on Oct. 20, 2006. | ||
| Prior Publication US 2008/0094129 A1, Apr. 24, 2008 | ||
| Int. Cl. G05F 1/10 (2006.01) | ||
| U.S. Cl. 327—536 | 7 Claims |
| 1. A voltage-booster power supply circuit comprising:
a semiconductor integrated circuit operating in a first mode and a second mode; and
an external circuitry connected to said semiconductor integrated circuit,
wherein said semiconductor integrated circuit has:
a first charge pump circuit and a second charge pump circuit each of which boosts a first voltage by using a capacitor to
generate a second voltage in response to a control signal; and
a selection circuit configured to output a first control signal and a second control signal as said control signal, which
are out-of-phase with each other, respectively to said first charge pump circuit and said second charge pump circuit in said
first mode, and to output an in-phase control signal as said control signal to said first charge pump circuit and said second
charge pump circuit in said second mode,
wherein in a case of said first mode, said external circuitry is provided with a first pumping capacitor and a second pumping
capacitor that are connected as said capacitor to said first charge pump circuit and said second charge pump circuit, respectively,
wherein in a case of said second mode, said external circuitry is provided with a common pumping capacitor that is connected
as said capacitor to said first charge pump circuit and said second charge pump circuit in common.
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