XR81111 Universal Clock - High Frequency LVPECL Clock Synthesizer General Description FEATURES XR81111-CA04: Factory Configured 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 Footprint compatible with 5mm x 7mm differen- tial oscillators selectable output frequencies. The device is optimized for use with a 25MHz One differential LVPECL output pair crystal (or system clock) and generates a selection of output frequencies - Crystal oscillator interface which can also be 156.25MHz for 10GE/XAUI, 150MHz for SAS, 125MHz for GE and 100MHz overdriven using a single-ended reference clock for PCIe applications. Output frequency range: 100MHz - 156.25MHz The application diagram below shows a typical synthesizer configuration Crystal/input frequency: 25MHz, parallel resonant with any standard crystal oscillating in fundamental mode. Internal load crystal capacitors are optionally available to minimize/eliminate external crystal VCO range: 2GHz - 3GHz loads. A system clock can also be used to overdrive the oscillator for a syn- RMS phase jitter 156.25MHz, 12kHz - 20MHz: chronous timing system. <0.60ps Full 3.3V or 2.5V operating supply The typical phase noise plot below shows the jitter integrated over the -40C to 85C ambient operating temperature 12KHz to 20MHz range that is widely used in WAN systems. Most LAN Lead-free (RoHS 6) package applications however use the integration range of 1.875MHz to 20MHz. These clock devices show a very good high frequency noise floor below - APPLICATIONS 150dB. 10GE, GE LAN/WAN The XR81111 is a family of Universal Clock synthesizer devices in QFN-10 2.5G/10G SONET/SDH/OTN packages that are footprint compatible with industry standard 5mm x 7mm xDSL, PCIe oscillators. The devices generate ANY frequency in the range of 100 MHz to Low-jitter Clock Generation 1.5GHz by utilizing a highly flexible delta sigma modulator and a wide rang- Synchronized clock systems ing VCO. The high clock frequency LVPECL outputs have very low phase noise jitter of sub 0.6ps, while consuming extremely low power. These Ordering Information page 12 devices can be used with standard crystals or external system clock and can be configured to select from four different frequency multiplier settings to support a wide variety of applications. This family of products have an extremely low power PLL block with core power consumption less than 40% of the equivalent devices from competition. By second sourcing several of the existing sockets, these devices provides a very compelling power effi- ciency 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 XR81111 PHASE NOISE (dBc/Hz) XR81111 CA04 -40db V CC Q 2.5V or 3.3V RMS Jitter = 532.3fs -60db XTAL IN 100MHz to 156.25MHz Int Range 12KHz to 20MHz -80db 25MHz Q XTAL OUT -100db Enable OE -120db FSEL1 -140db Freq Select FSEL0 -160db V EE -180db 100Hz 1KHz 10KHz 100KHz 1MHz 10MHz 2014 Exar Corporation 1 / 12 exar.com/XR81111 Rev 1BXR81111 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 / 12 exar.com/XR81111 Rev 1B