The ZL30105 is a high-performance DPLL (digital phase-locked loop) designed for synchronization and timing control of redundant system clocks requiring Stratum 3 and SDH timing specifications. The ZL30105 generates SBI, ST-BUS and other TDM clock and framing signals that are phase locked to one of three network references. It helps ensure system reliability by monitoring its references for frequency accuracy and stability and by maintaining tight phase alignment between redundant primary and secondary system clocks even in the presence of high network jitter. The ZL30105 is intended to be the central timing and synchronization resource for network equipment that complies with ITU-T, Telcordia, ETSI and ANSI network specifications.