Patent ID: 6384668
Filing Date: 2002-05-07
Classification: H03L

Abstract:
A charge pump circuit comprising:a first transistor connected between a first power source and an output node; and a second transistor connected between a second power source and said output node; wherein the first and the second transistors are controlled in response to a first signal and a second signal so as to control a current flowing into and out of the output node, said charge pump circuit further comprising: a first switch circuit connected between a base of the first transistor and a first input node through which the first signal is input and controlling the first transistor in response to the first signal, wherein the first switch circuit includes a bias circuit connected to the second power source; a second switch circuit connected between a base of the second transistor and a second input node through which the second signal is input and controlling the second transistor in response to the second signal; a phase comparator producing, as output signals, said first signal and said second signal, said first signal and said second signal being determined in accordance with a determination made by said phase comparator in response to a third signal and fourth signal being input to said phase comparator; and wherein the first and the second transistors and transistors contained in the first and the second switch circuits are all NPN transistors.