The ZL30108 SONET/SDH network interface digital phase-locked loop (DPLL) provides timing and synchronization for SONET/SDH network interface cards. Measuring just 5 mm (millimeters) x 5 mm, the ZL30108 DPLL addresses dense line card "real estate" constraints. The device may be used in combination with Microchip's family of analog PLLs to provide an end-to-end timing and synchronization solution for higher-speed SONET/SDH networking equipment. For example, the ZL30108 DPLL and ZL30415 analog PLL provide an easy-to-implement, compact solution for OC-12/STM-4 line cards.