发明授权
- 专利标题: Direct synthesis clock generation circuits and methods
- 专利标题(中): 直接合成时钟生成电路和方法
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申请号: US11432113申请日: 2006-05-11
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公开(公告)号: US07391842B1公开(公告)日: 2008-06-24
- 发明人: John Laurence Melanson
- 申请人: John Laurence Melanson
- 申请人地址: US TX Austin
- 专利权人: Cirrus Logic, Inc.
- 当前专利权人: Cirrus Logic, Inc.
- 当前专利权人地址: US TX Austin
- 代理机构: Thompson & Knight LLP
- 代理商 James J. Murphy
- 主分类号: H03D3/24
- IPC分类号: H03D3/24
摘要:
Clock signal generation circuitry includes input circuitry for receiving a frequency control input signal and a clock signal and generating a memory address therefrom, a memory for storing digital data indexed by the memory address and representing real and imaginary parts of a complex digital waveform, and digital to analog conversion circuitry. The digital to analog conversion circuitry includes real-part digital to analog conversion circuitry for converting digital data retrieved from the memory and representing the real part of the complex waveform into a real-part analog signal and imaginary-part digital to analog conversion circuitry for converting digital data retrieved from the memory and representing the imaginary part of the complex waveform into an imaginary-part analog signal. The clock signal generation circuitry also includes analog filtering circuitry having real-part filtering circuitry for filtering the real-part analog signal to generate a filtered real-part analog signal and imaginary-part filtering circuitry for filtering the imaginary-part analog signal to generate a filtered imaginary-part analog signal. Analog to digital conversion circuitry is provided for converting the filtered real-part and imaginary-part analog signals into a digital clock signal at a rate near an integer multiple of a frequency of the filtered real-part and imaginary-part analog signals.
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