XR81102 Universal Clock - High Frequency LVPECL Clock Synthesizer FEATURES General Description XR81102-CA02: Factory configured The XR81101-CA02 is a clock synthesizer operating at a 3.3V/2.5V supply One differential LVPECL output pair with Integer divider, using a 25MHz parallel resonant crystal reference input Crystal oscillator interface which can also be provides a 125MHz LVPECL outputs. The device is optimized for use with a overdriven using a single-ended reference clock 25MHz crystal (or system clock) and generates a 125MHz output clock for Output frequency: 125MHz GE applications. The LVPECL outputs have very low phase noise jitter of Crystal/input frequency: 25MHz, parallel resonant sub 150fs, while consuming extremely low power. crystal The application diagram below shows a typical synthesizer configuration RMS phase jitter 125MHz, 1.875MHz - 20MHz: < 150fs with any standard crystal oscillating in fundamental mode. Internal load Full 3.3V or 2.5V operating supply capacitors are optionally available to minimize/eliminate external crystal loads. A system clock can also be used to overdrive the oscillator for a syn- -40C to 85C ambient operating temperature chronous timing system. Lead-free (RoHS 6) package The typical phase noise plot below shows the jitter integrated over the APPLICATIONS 1.875MHz to 20MHz range that is widely used in WAN systems. These Gigabit Ethernet clock devices show a very good high frequency noise floor below -150dB. Low-jitter Clock Generation The XR81102 is a family of Universal Clock synthesizer devices in TSSOP- Synchronized clock systems 8 packages. The devices generate ANY frequency in the range of 100MHz to 1.5GHz by utilizing a highly flexible delta sigma modulator and a wide Ordering Information page 8 ranging VCO. These devices can be used with standard crystals or external system clock to support a wide variety of applications. This family of prod- ucts has an extremely low power PLL block with core power consumption 40% less than the equivalent devices from competition. By second sourcing several of the existing sockets, these devices provides a very compelling power efficiency value benefit across all market segments. Other clock multiplier and/or driver configurations are possible in this clock family and can be requested from the factory Typical Application XR81102 PHASE NOISE (dBc/Hz) XR81102CA02 -40db V CC Q 2.5V or 3.3V RMS Jitter = 120.9fs -60db Int Range 1.875MHz to 20MHz XTAL IN -80db 125MHz 25MHz -100db Q XTAL OUT -120db Enable OE -140db V EE -160db -180db 100Hz 1KHz 10KHz 100 KHz 1MHz 10MHz 2014 Exar Corporation 1 / 8 exar.com/XR81102 Rev 1BXR81102 Absolute Maximum Ratings Operating Conditions Stresses beyond those listed under Absolute Maximum Operating Temperature Range.....................-40C to +85C Ratings may cause permanent damage to the device. Exposure to any Maximum Rating condition for extended periods may affect device reliability and lifetime. Supply Voltage..........................................................+4.2V Input Voltage......................................-0.5V to VCC + 0.5V Output Voltage...................................-0.5V to VCC + 0.5V Reference Frequency/Input Crystal.........10MHz to 60MHz Storage Temperature................................-55C to +125C Lead Temperature (Soldering, 10 sec).....................300C ESD Rating (HBM - Human Body Model)....................2kV 2014 Exar Corporation 2 / 8 exar.com/XR81102 Rev 1B