发明授权
US08207766B2 Method and apparatus for quantization noise reduction in fractional-N PLLs
有权
分数N PLL中量化噪声降低的方法和装置
- 专利标题: Method and apparatus for quantization noise reduction in fractional-N PLLs
- 专利标题(中): 分数N PLL中量化噪声降低的方法和装置
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申请号: US12732029申请日: 2010-03-25
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公开(公告)号: US08207766B2公开(公告)日: 2012-06-26
- 发明人: Qicheng Yu
- 申请人: Qicheng Yu
- 申请人地址: US TX Austin
- 专利权人: Silicon Laboratories Inc.
- 当前专利权人: Silicon Laboratories Inc.
- 当前专利权人地址: US TX Austin
- 代理机构: Zagorin O'Brien Graham LLP
- 主分类号: H03L7/06
- IPC分类号: H03L7/06
摘要:
A first current source supplies a first charge amount responsive to a first pulse signal from the phase frequency detector and a second current source supplies a second charge amount according to a fixed value and a variable value. The variable value corresponds to a phase difference between a first feedback clock signal and a hypothesized feedback clock signal with reduced quantization noise. The first and second charge amounts are of opposite polarity. A single set of first and second current sources perform the functions of charge pump and noise reduction DAC.
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