| 摘要 |
PROBLEM TO BE SOLVED: To increase efficiency until an output voltage reaches a desired voltage value. SOLUTION: A charge pump circuit 30 inputs a power source voltage Vcc that has been supplied and boosts an output signal to a desired voltage value by repeated switchings. A detecting circuit 10 detects the value of the power source voltage supplied to the charge pump circuit 30 and the voltage value of the output signal outputted from the charge pump circuit 30, detects whether or not the voltage value of the output signal is lower than the value of the power source voltage by comparing the value of the power source voltage and the voltage value of the output signal, and transmits the result to a bypass circuit 20. The bypass circuit 20 bypasses a power source voltage Vcc to an output terminal when the detecting circuit 10 detects that the voltage of the output signal from the charge pump circuit 30 is lower than the power source voltage Vcc. By this means, the power source voltage Vcc is added to an output voltage Vout. COPYRIGHT: (C)2003,JPO
|
