Charge pump circuit

Abstract

Provided is a charge pump circuit capable of shortening a settling time. When a boosted voltage (Vout) becomes high to be equal to or larger than an overshoot voltage, a transistor (T1) is turned on and an output terminal of the charge pump circuit is discharged. Accordingly, it is easy to reduce the boosted voltage (Vout) after an occurrence of an overshoot, and a period of time in which the boosted voltage (Vout) decreases from a voltage after the occurrence of the overshoot to a desired voltage is shortened, leading to a reduction in a settling time.

Description

technical field [0001] The present invention relates to charge pump circuits. Background technique [0002] The configuration of a conventional charge pump circuit will be described. Figure 5 is a diagram showing a conventional charge pump circuit. [0003] The charge pump circuit has a voltage dividing circuit 23 , a reference voltage circuit 28 , a comparison circuit 22 , an oscillation circuit 20 and a voltage boosting circuit 21 . [0004] Next, the operation of the conventional charge pump circuit will be described. [0005] The boosting circuit 21 performs a boosting operation based on the pump pulse output from the oscillation circuit 20, and outputs a boosted voltage Vout. The voltage dividing circuit 23 divides the boosted voltage Vout and outputs a divided voltage Vfb1. The reference voltage circuit 28 outputs a reference voltage Vref1. The comparison circuit 22 compares the divided voltage Vfb1 with the reference voltage Vref1 and operates (feedback control) ...

AI Technical Summary

Problems solved by technology

[0008] However, since there is a parasitic capacitance or the like in the feedback system from the output terminal of the charge pump circuit to the oscillation circuit 20, a delay may occur in the feedback control and an overshoot may occur at the output terminal of the charge pump circuit.

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