A DLL With Jitter Reduction Techniques and Quadrature Phase Generation for DRAM Interfaces

A DLL featuring jitter reduction techniques for a noisy environment is described. It controls a loop response mode by monitoring the magnitude of input jitter caused by supply noise. This technique varies the probability of phase error tracking. It reduces the output jitter of the DLL due to a low effective variance of input phase error and a narrow effective loop bandwidth. The DLL is implemented in a 0.13 mum CMOS process. Under noisy environments, the output clock of 1 GHz has 4.58 ps RMS and 29 ps peak-to-peak jitter.