Universal Quad Clock - High Frequency LVCMOS/LVDS/LVPECL Clock Synthesizer


The XR81411 is a Quad Clock synthesizer with 4 independent PLLs in a compact LGA-45 package. Each synthesizer generates ANY frequency in the range of 10 MHz to 800MHz by utilizing a highly flexible delta sigma modulator and a wide ranging VCO. The outputs are independently configurable for single ended LVCMOS or differential LVDS or LVPECL. The clock outputs have very low typical phase noise jitter of sub 0.6ps RMS, while consuming extremely low power. The XR81411 uses a single reference and provides 4 independent outputs that can be configured as needed to support a wide variety of applications.

Each of the XR81411’s 4 independent PLLs include an integer/fractional divider, LVCMOS/LVDS/LVPECL output driver, 3.3V/2.5V supply, and generates one of four selectable output frequencies from a single reference. The XR81411 is optimized for use with a fundamental mode 10MHz to 60MHz crystal (or system clock) and generates a selection of output frequencies ranging from 10MHz to 800MHz in either integer or fractional mode. In fractional mode, frequency resolution of better than 2Hz steps can be achieved.

The application diagram shows a typical LAN synthesizer configuration with any standard crystal oscillating in fundamental mode.

The typical phase noise plot shows the jitter integrated over the 12KHz to 20MHz range that is widely used in these systems.

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  • Small footprint 5mm x 5mm LGA package
  • 4 Independent Configurable Outputs - As differential LVPECL/LVDS pair or as a single ended LVCMOS.
  • Crystal oscillator interface which can also be overdriven using a single-ended reference clock
  • Output frequency range: 10MHz - 800MHz
  • Crystal/input frequency: 10MHz to 60MHz, parallel resonant crystal
  • VCO range: 2GHz - 3GHz
  • Phase jitter @
    • 125MHz (12KHz - 20MHz): <0.6ps RMS
    • 125MHz (1.875MHz -20MHz): <0.2ps RMS
  • 3.3V or 2.5V operating supply
  • -40°C to 85°C ambient operating temperature
  • Lead-free (RoHS 6) package

Configure & Sample: Universal Clocks


  • 10GE, GE LAN/WAN
  • 2.5G/10G SONET/SDH/OTN
  • xDSL, PCIe
  • Low-jitter Clock Generation
  • Synchronized clock systems

Design Tools


Pkg Code Details Quantities Dimensions PDF

Parts & Purchasing

Part Number Pkg Code RoHS Min Temp Max Temp Status Buy Now Order Samples
XR81411-F LGA-45 -40 85 OBS
XR81411TR-F LGA-45 -40 85 OBS
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Part Status Legend
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.
Distribution Date Description File
07/11/2017 Product Discontinuation Notification Product Discontinuation Notice 17-0623-02 r-1033.pdf

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