A high-performance charge pump with improved static and dynamic matching characteristic

A high-performance Charge Pump (CP) is introduced in this paper with both perfect static and dynamic matching properties. Pseudo-cascode structure and bulk-biasing technique are adopted to obtain a high equivalent output impedance over a wide voltage range as well as a fast transient behavior. Besides, by analyzing turn-on and turn-off mechanisms, a MOS capacitor is inserted to weaken the coupling from current switch to reduce the conduction time and an extra discharging path is added to accelerate the turn-off speed. A prototype is implemented in SMIC 130nm CMOS process. The simulation results show that the maximum static mismatch is only 0.37% and the largest ripple on VCO control voltage is 1.97mV over process, temperature and supply voltage variable. The amount of reference spur is -73.1dBc in the PLL output signal while the conventional one´s level is -52dBc.