Reconfigurable 2.5 GHz phase-locked loop for system on chip applications

2.5 GHz phase-locked loop (PLL) suitable for system-on-the-chip (SOC) implementation is presented. PLL can be configured as a clock multiplication unit (CMU) or as a clock recovery unit (CRU) for data muxing or jitter clean-up applications. It uses a phase-frequency detector (PFD), a low voltage charge-pump, and a low power H-bridge output driver. Phase locked-loop architecture is of Type IV that results in superior performance for power supply rejection ratio (PSRR). The circuit has been implemented in 0.18 /spl mu/m standard CMOS process, occupies 1230 /spl mu/m by 248 /spl mu/m and dissipates 128 mW from a 1.8V power supply.