Abstract: A monolithic clock recovery circuit is proposed in this paper. The frequency of the recovered clock is 125MHz. By using of some compensation methods, such as current subtraction technology, the gain of the VCO is greatly diminished, as a result the chip area is reduced also without sacrificing the noise performance of the recovered clock. This design is implemented by a 0.25m standard CMOS technology. The active chip area is less than 0.2mm2, and the power consumption is only 10mW. The simulation results in different temperature and process condition indicate that the phase error of the recovered clock is less than 200ps and the peak-to-peak jitter is less than 150ps. A 100MHz PHY with the proposed clock recovery circuit inside is taped out and tested. The test result shows that the clock recovery circuit works properly.