| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a charge pump for accurately outputting a voltage of a desired voltage value, without requiring speedily operating comparators. <P>SOLUTION: The charge pump 1 includes a switch circuit 20 interposed among output capacitors C1, C2, a flying capacitor C3, and input power supplies HPVDD, SPVDD; and a control section 10. The control section 10 allows the input power supplies to charge the flying capacitor C3 via the switching circuit 20, and to make a voltage distribute to the output capacitor C2 from the flying capacitor C3. The control section 10 includes a charge control means which gradually increases the conductance or the output current value of a P-channel transistor P5, when the input power supply SPVDD charges the flying capacitor C3, detects that a charge voltage CP of the flying capacitor C3 which exceeds a reference voltage VLMT imparted in advance, and then turns off the transistor. <P>COPYRIGHT: (C)2011,JPO&INPIT |
