| 摘要 |
PROBLEM TO BE SOLVED: To acquire a charge pump power supply circuit for utilizing a form of a basic constitution of a charge pump circuit and limiting an inrush current without adding new circuits such as a circuit for precharging a capacitor and an auxiliary switch. SOLUTION: In the basic constitution of the charge pump circuit, a basic circuit 1a of a voltage boosting circuit comprises three PMOS transistors Q11, Q12, Q13 two of which implement a charging operation and are connected on the input power supply Vin side in parallel, and three NMOS transistors Q31, Q32, Q33 two of which implement a boosting operation (a discharging operation) and are connected on the input power supply Vin side in parallel. These composite on-resistance values equal to one MOS transistor. The on-resistance values have relationships Q11>Q12>Q13, Q31>Q32>Q33. The Q11, Q31 is turned on just after an activation, and the inrush current is limited. Then, the Q12, Q22 are additionally turned on. Furthermore, the Q13, Q23 are additionally turned on, and a desired boosted voltage is acquired. COPYRIGHT: (C)2006,JPO&NCIPI
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