An Improved Design of Proportional-Integral Digital Loop Filter

To improve the linearity of system using nonlinear Bang-Bang phase detector, this paper presents a proposed digital loop filter (DLF) with coefficients that adapt to relative magnitude of the phase error, improved system linearity. In AMS digital and analog simulation environment, clock and data recovery adopting the proposed DLF is simulated. The simulation results shows that the linearity of the clock and data recovery adopting proposed DLF increases by 60% at most compared to adopting conventional proportional-integral DLF.