| 摘要 |
The present invention discloses a charge-pump circuit, which contributes to the improvement of the reliability of capacitor for boosting provided inside even under the condition where supply voltage is changed, and which also contributes to the reduction of consumption current. In this charge-pump circuit, a constant voltage generation circuit generates a reference voltage VS lower by a fixed voltage VT than a supply voltage VB of a power source +B and gives the reference voltage to a booster circuit. The booster circuit comprises an inverter circuit for alternately changing output voltage between the supply voltage VB and the reference voltage VS in response to reverse operation in synchronization with the output of an oscillation circuit, and also an inverter circuit for alternately changing output voltage between the reference voltage VS and the supply voltage VB in response to periodic reverse operation with a phase by 180° different from the phase of said inverter, whereby charging current is supplied via a diode to a first capacitor from the power source +B during the period when output of the inverter circuit is changed to the reference voltage VS, and electric charge charged on the first capacitor is shifted to the second capacitor via the diode during the period when output of the inverter circuit is changed to the reference voltage VS.
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