Charge pump circuit

Abstract

The charge pump circuit comprises first and second charge transferring MOS transistors M1, M2 connected in series; a capacitor C1 connected at its first terminal to the connection point of the MOS transistors M1, M2; an integrating circuit 21 that generates a ramp voltage corresponding to a clock CLK; a comparator 15 that compares the ramp voltage with a voltage corresponding to an output voltage Vout from the second MOS transistor M2; a frequency divider 22 that divides the clock CLK into a half; and a NAND circuit 16 that masks an output of the comparator 15 according to a frequency-divided output of the frequency divider 22. The output of the NAND circuit 16 is impressed to the second terminal of the capacitor C1.

Description

technical field

[0001] The invention relates to a charging pump circuit, in particular to a charging pump circuit whose output voltage has the function of regulating. Background technique

[0002] A charge pump circuit consists of a charge transfer device, a capacitor, a clock driver, etc. It is a circuit that boosts an input voltage and outputs it, and is widely used in power supply circuits of transistor circuits, etc. Conventionally, in order to stabilize the output voltage of the charge pump circuit, an operational amplifier is used as a series regulator to adjust the output voltage to a desired constant voltage. A charge pump circuit using a regulator is described in Patent Document 1, for example.

[0003] However, when the output voltage of the charge pump circuit does not want to be adjusted very high, when it is desired to ignore the capacitance value of the smoothing capacitor connected to the output of the charge pump circuit in the previous stage of the regulato...

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