| 摘要 |
PROBLEM TO BE SOLVED: To provide a differential charge pump and a method which enables to reduce a switching noise and additionally, whose circuit composition is simple, as well as a phase locked loop using this and a method. SOLUTION: The differential charge pump inputs a first input signal, a second input signal, a reversed signal of the above second input signal and a reserved signal of the above first input signal, thereto respectively, and includes a first to a fourth driver which generates a first output signal, a second output signal, a third output signal with an identical voltage level of the above first output signal and a fourth output signal with an identical voltage level of the above second output signal, and includes a first to a fourth transistor which has a gate connected to a first or a second bias voltage, a source to which the above first, second, third or fourth output signal is applied and a drain connected to a first or a second differential charge pump output signal. The first to the fourth transistor and each driver are connected in series. COPYRIGHT: (C)2004,JPO&NCIPI
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