Invention Grant
- Patent Title: PLLS covering wide operating frequency ranges
- Patent Title (中): PLLS涵盖了广泛的工作频率范围
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Application No.: US11707778Application Date: 2007-02-12
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Publication No.: US07692497B2Publication Date: 2010-04-06
- Inventor: Jianbin Hao , Ning Zhu , Yanjing Ke
- Applicant: Jianbin Hao , Ning Zhu , Yanjing Ke
- Applicant Address: US CA Santa Clara
- Assignee: Analogix Semiconductor, Inc.
- Current Assignee: Analogix Semiconductor, Inc.
- Current Assignee Address: US CA Santa Clara
- Agency: Blakely Sokoloff Taylor & Zafman LLP
- Main IPC: H03L7/00
- IPC: H03L7/00

Abstract:
The present invention provides a method and mechanism for adapting a single phase-locked loop (PLL) for a wider range of frequencies than has been possible with prior art solutions. An analog comparator circuit that senses the output of a charge pump and provides a signal to a digital control circuit to choose a suitable load circuit for the PLL voltage controlled oscillator (VCO). The analog comparator with the digital control circuit changes the VCO loads to select the best VCO range to achieve the incoming signal frequency lock. A single PLL with the VCO load selection method disclosed, with use of built-in hysteresis, in addition to the phase and frequency feedback of the prior art, allows multiple overlapping frequency ranges to be covered in a stable fashion. This enables frequency locking of the PLL over a wide range of frequencies with a small die size and low power consumption.
Public/Granted literature
- US20080191760A1 PLLS covering wide operating frequency ranges Public/Granted day:2008-08-14
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