A low jitter phase-locked loop (PLL) based on self-biased techniques was designed. The PLL achieves process independent and low input tracking jitter. A novel cascode charge pump (CP) is realized to improve the current matching so as to reduce the jitter of the system. A capacitor is employed in the second CP to make third order PLL. The PLL is fabricated in SMIC 0.13 μm CMOS process, which achieves a very wide tuning range from 625MHz to 1.5GHz. And the phase noise of the VCO at 1MHz offset from the 1.25GHz only has -94.66dBc/Hz. The measured RMs jitter and peak-to-peak jitter at 1.25GHz only have 3.53ps and 21.19ps.
