| 摘要 |
PROBLEM TO BE SOLVED: To provide a charge pump system of a boosting circuit which can perform quick boosting to specified potential and can reduce power consumption after boosted to the specified potential. SOLUTION: The output voltage Vout of a boost processor 20 is divided by resistors 41 and 42, and the divided output voltage Va is inputted into one of comparators 45. A reference voltage Vb divided by resistors 43 and 44 from a voltage Vcc is inputted into the other of the comparators 45. The comparator 45 compares the divided output voltage Va with a reference voltage Vb, and in the case that the divided output voltage Va is lower than the reference voltage, it outputs a High voltage, and in the case that the divided output voltage Va is higher, it outputs a Low voltage. Therefore, a signal oscillator 10 oscillates (an N-type CMOSFET 18 is is an off-state) while the output voltage Vout does not exceed a threshold determined by the reference voltage Vb, and when it exceeds the threshold, the oscillator oscillates (the CMOSFET is in an on-state) at a low frequency. COPYRIGHT: (C)2007,JPO&INPIT
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