A wide range PLL for 64X speed CD-ROMs & 10X speed DVD-ROMs

In this paper, we propose a wide range PLL(Phase Locked Loop) for 64X speed CD-ROMs and 10X speed DVD-ROMs, In order to develop a PLL with a wide lock ing range we designed dual loop scheme consists of a frequency detection lo op and phase detection loop. The PLL has a locking range of 75MHz similar t o 370MHz A new V-I converter and a differential delay cell are used in a 3- stage ring VCO to reduce jitters. In addition, we propose a new charge pump which has perfect current matching characteristics for sourcing/ sinking c urrents. This new charge pump improves the phase offset that reduce locking range of the PLL. Implemented in a 0.25 um, 1-poly 5-metal CMOS process. I t occupies an active area of 1.8mm * 1.1mm.