| 摘要 |
If single-stage boosting is selected by a mode selection circuit, drive signals (S1, S3) are supplied as in-phase signals, and a switch (SW1) is kept closed by a control signal (S2), thereby controlling first and second charge pumps to boost the power supply voltage at the same timing. If two-stage boosting is selected, drive signals (S1, S3) are supplied as complementary signals, and the switch (SW1) is controlled by a control signal (S2), thereby controlling the first charge pump to boost the power supply voltage and controlling the second charge pump to further boost the boosted voltage. By this operation, even if single-stage boosting is selected, the first and second charge pumps can be used as a single charge pump.
|
