发明授权
US6100721A Circuit and method of extending the linear range of a phase frequency
detector
有权
扩展相位频率检测器的线性范围的电路和方法
- 专利标题: Circuit and method of extending the linear range of a phase frequency detector
- 专利标题(中): 扩展相位频率检测器的线性范围的电路和方法
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申请号: US241669申请日: 1999-02-01
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公开(公告)号: US6100721A公开(公告)日: 2000-08-08
- 发明人: Jeffrey C. Durec , David K. Lovelace , Albert H. Higashi
- 申请人: Jeffrey C. Durec , David K. Lovelace , Albert H. Higashi
- 申请人地址: IL Schaumburg
- 专利权人: Motorola, Inc.
- 当前专利权人: Motorola, Inc.
- 当前专利权人地址: IL Schaumburg
- 主分类号: G01R25/00
- IPC分类号: G01R25/00 ; H03D13/00 ; H03L7/089 ; H03L7/10 ; H04L27/00
摘要:
A wireless communication system (10) uses a phase detector (28) having a first pair of flip-flops (50, 56) for detecting the phase difference between an input frequency and a reference frequency. The first pair of flip-flops control current sources (66, 70) in the charge pump of the phase detector to modulate the error signal. A second pair of flip-flops (52, 58) detect when the input frequency is more than 2.pi. ahead of or behind the reference frequency. The second pair of flip-flops increment and decrement a counter (54) which in turn controls additional current sources (78-88) in the charge pump. The additional current sources extend the linear operating range of the error signal when the phase error exceeds .+-.2.pi..
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