A current-adjustable charge pump circuit
Patent Information
- Authority / Receiving Office
- CN · China
- Current Assignee / Owner
- 东莞润风电子科技有限公司
- Publication Date
- 2008-09-17
- Estimated Expiration
- Not applicable · inactive patent
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Abstract
Description
technical field
[0001] The invention relates to a charge pump circuit, in particular to a charge pump circuit with adjustable current, which is mainly applied to a charge pump integrated module in an integrated phase-locked loop. Background technique
[0002] The application of the charge pump phase-locked loop is very extensive. Generally speaking, the charge pump in the phase-locked loop is composed of two current sources with switches, and the output of the pre-stage frequency or phase detector (PFD) determines the switch. The opening and closing of the circuit, so as to decide whether to pump the charge into the loop filter of the subsequent stage or pump the charge out of the loop filter of the subsequent stage, and the resulting control voltage (vctrl) to control the post-stage loop filter stage voltage controlled oscillator (vco). The reason why the current of the charge pump circuit is adjustable is to flexibly adjust the above-mentioned control voltage (vctrl), so ...