XR81111

XR81111 Universal Clock - High Frequency LVPECL Clock Synthesizer General Description The XR81111-CA04 is a clock synthesizer with Integer divider, LVPECL driver, 3.3V/2.5V supply, taking a 25MHz Xtal input and providing one of four selectable output frequencies. The device is optimized for use with a 25MHz crystal (or system clock) and generates a selection of output frequencies 156.25MHz for 10GE/XAUI, 150MHz for SAS, 125MHz for GE and 100MHz for PCIe applications. The application diagram below shows a typical synthesizer configuration with any standard crystal oscillating in fundamental mode. Internal load capacitors are optionally available to minimize/eliminate external crystal loads. A system clock can also be used to overdrive the oscillator for a synchronous timing system. The typical phase noise plot below shows the jitter integrated over the 12KHz to 20MHz range that is widely used in WAN systems. Most LAN applications however use the integration range of 1.875MHz to 20MHz. ...