AD9547,pdf datasheet (Oscillat

The AD9547 provides synchronization for many systems, including synchronous optical networks (SONET/SDH). The AD9547 generates an output clock that is synchronized to one of two differential or four single-ended external input references. The digital PLL allows for reduction of input time jitter or phase noise associated with the external references. The AD9547 con-tinuously generates a clean (low jitter), valid output clock, even when all references fail, by means of digitally controlled loop and holdover circuitry.

The AD9547 operates over an industrial temperature range of −40°C to +85°C.
Applications
Network synchronization
Cleanup of reference clock jitter
SONET/SDH clocks up to OC-192, including FEC
Stratum 2 holdover, jitter cleanup, and phase transient control
Stratum 3E and Stratum 3 reference clocks
Wireless base stations, controllers
Cable infrastructure
Data communications