XAPP854-数字锁相环(DPLL)参考设计 Many applications require a clock signal to be synchronous, phase-locked, or derived fromanother signal, such as a data signal or another clock. This type of clock circuit is important in

many communications or audio video applications to keep data synchronized. In a digitalFPGA-based system, this function often uses external mixed-signal ICs, which add additionalcost, power, and complexity to the system. This application note and reference design providea digital phase-locked loop (DPLL) solution that utilizes spare resources in a Virtex™-4 FPGAand requires minimal external components. The performance of the DPLL is superior to mostintegrated mixed-signal solutions. The DPLL design can be used in many different applications,including jitter reduction PLLs, clock multiplier PLLs, clock recovery PLLs, and clockgenerators.