| 摘要 |
PROBLEM TO BE SOLVED: To provide a charge pump circuit which obtains a desired output voltage without using a linear regulator. SOLUTION: A conventional charge pump circuit is constituted of diodes 11 and 14, capacitors 13 and 15, and a buffer 16. A negative feedback circuit is constituted to include a differential amplifier 20 to convert a voltage charged in the capacitor 13 into a voltage V20 based on a ground potential GND, a differential amplifier 30 to output a voltage V30 according to a difference between a voltage obtained by dividing an output voltage OUT and a reference voltage REF, and a comparator 50 to output a signal V50 having a hysteresis characteristic according to the voltages V20 and V30, to drive the buffer 16 by the signal V50. The desired output voltage OUT is acquired without using the linear regulator by properly setting a division ratio of the output voltage OUT and the reference voltage REF. COPYRIGHT: (C)2009,JPO&INPIT
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