A Perfectly Current Matched Charge Pump of CP-PLL for Chip-to-Chip Optical Link

A new charge pump (CP) with perfectly current matching and less sensitive to power supply noise is proposed for charge pump-phase locked loops (CP-PLL) in chip-to-chip optical link. The difference of charged/discharged currents in the proposed CP is less than 1% over a wide CP output voltage range in a 0.18 mum CMOS technology.