Booster circuit

The objective of the invention is to provide a booster circuit with reduced power consumption and switching noise. Booster circuit 1 of the present invention has gate circuits 41-47 an auxiliary control circuit 9. Each of gate circuits 41-47 has charging/discharging circuit 11 and auxiliary charging/discharging circuit 12 used for charging/discharging capacitors 51-57. Under the control of auxiliary control circuit 9, said charging/discharging circuit 11 can operate independently or operate together with auxiliary charging/discharging circuit 12. When the booster circuit is started, charging/discharging circuit 11 and auxiliary charging/discharging circuit 12 are operated together to increase the drivability of gate circuits 4. As a result, the charging time of capacitors 51-57 in charge-pump circuits 21-27 can be shortened. On the other hand, at steady state, charging/discharging circuit 11 operates independently. As a result, the drivability of the gate circuits is reduced compared with that at the time when the booster circuit is started. Consequently, the loss in power consumption and noise can be reduced.