Cycle Slipping Cancellation in Bang-Bang PLLs

Digital phase-locked loops (DPLLs) based on bang-bang phase detectors (BBPD) are now very common in many communication systems specially in clock and data recovery. However, it suffers from long settling time due to cycle slipping issue and even at some point it fails to achieve lock. This paper presents a simple and efficient technique to resolve the issue of locking failure in bang-bang phase-locked loops (BBPLL) by detecting the instants of cycle slipping and cancelling its effect. Simulation results show that locking is achieved with the proposed cycle slipping cancellation (CSC) technique for cases at which the conventional BBPLL fails to achieve lock.