PHASE LOCK LOOP PRECONDITIONING CIRCUIT

摘要

PHASE LOCK LOOP PRECONDITIONING CIRCUIT A preconditioning circuit is inserted in series between a coded stream of data pulses and a standard commercially available phase lock loop of the type having a nonharmonic phase detector. The novel preconditioning circuit converts the input coded stream of data pulses which do not have a transition during each cell time into a stream of pulses having a transition during each data cell time to enable the nonharmonic phase lock loop to synchronize with the data cell time and to produce clock pulses synchronized with the data cell time.