The DS3102 is a low-cost, feature-rich timing IC for telecom timing cards. With 8 input clocks, the device directly accepts both line timing from a large number of line cards and external timing from external DS1/E1 BITS transceivers. The DS3102 continually monitors all input clocks and performs automatic hitless reference switching if the primary reference fails. The T0 DPLL complies with the Stratum 3 requirements of GR-1244, GR-253, and the requirements of G.813 and G.8262. The highly programmable DS3102 support numerous input and output frequencies including rates required