| 摘要 |
A clock data recovery circuit includes a phase detector circuit, a filter circuit, a parts per million (PPM) detector circuit, a PPM decoder circuit, a summation circuit, and a phase interpolator circuit. The phase detector circuit generates a phase error signal based on a periodic signal and a data signal. The filter circuit generates a filtered signal based on the phase error signal. The PPM detector circuit and the PPM decoder circuit generate control signals based on the filtered signal. The phase interpolator circuit generates the periodic signal. The clock data recovery circuit adjusts a phase of the periodic signal based on the filtered signal and the control signals in response to variations in a data rate of the data signal using spread-spectrum clocking in order to track changes in the data rate of the data signal. |
