Invention Grant
US08164369B2 Techniques for minimizing control voltage noise due to charge pump leakage in phase locked loop circuits
失效
在锁相环电路中由于电荷泵漏电而使控制电压噪声最小化的技术
- Patent Title: Techniques for minimizing control voltage noise due to charge pump leakage in phase locked loop circuits
- Patent Title (中): 在锁相环电路中由于电荷泵漏电而使控制电压噪声最小化的技术
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Application No.: US12367980Application Date: 2009-02-09
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Publication No.: US08164369B2Publication Date: 2012-04-24
- Inventor: Ashwin Raghunathan , Marzio Pedrali-Noy
- Applicant: Ashwin Raghunathan , Marzio Pedrali-Noy
- Applicant Address: US CA San Diego
- Assignee: Qualcomm Incorporated
- Current Assignee: Qualcomm Incorporated
- Current Assignee Address: US CA San Diego
- Agent Eric Ho
- Main IPC: H03L7/06
- IPC: H03L7/06

Abstract:
Techniques for adaptively control of a loop filter sampling interval to mitigate the effects of charge pump output noise in an apparatus including a phase lock loop circuit are provided. In one aspect, the apparatus includes a voltage controlled oscillator (VCO), a phase frequency detector (PFD) providing a phase comparison operation, a loop filter providing a control voltage to lock the VCO to a desired operating frequency, and a charge pump configured to provide an output signal to the loop filter in response to at least one of an UP pulse and a DOWN pulse. The apparatus further includes a sampling switch, coupled between an input of the loop filter, an output of the charge pump, and characterized by a sampling interval. A sampling switch controller is configured to adaptively control the width of the sampling interval in order to mitigate the effects of output noise from the charge pump by closing the sampling switch in advance of the phase comparison operation and opening the sampling switch when the phase comparison operation is completed.
Public/Granted literature
- US20100117701A1 TECHNIQUES FOR MINIMIZING CONTROL VOLTAGE NOISE DUE TO CHARGE PUMP LEAKAGE IN PHASE LOCKED LOOP CIRCUITS Public/Granted day:2010-05-13
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