The 8440259D-05 is a 9 output synthesizer optimized to generate Gigabit and 10 Gigabit Ethernet. Using a 25MHz, 18pF parallel resonant crystal, the device will generate 125MHz and 3.90625MHz clocks with mixed LVDS and LVCMOS/LVTTL output levels. The 8440259D- 05 uses IDT's 3rd generations low phase noise VCO technology and can achieve <1ps typical rms phase jitter, easily meeting Ethernet jitter requirements. The 8440259D-05 is packaged in a small, 32-pin VFQFN package that is optimum for applications with space limitations.


  • Five differential LVDS outputs at 125MHz
    Three LVCMOS/LVTTL single-ended outputs at 125MHz
    One LVCMOS/LVTTL single-ended output at 3.90625MHz
  • Selectable crystal oscillator interface or LVCMOS/LVTTL single-ended input and PLL bypass from a single select pin
  • VCO range: 510MHz - 650MHz
  • RMS phase jitter @ 125MHz, using a 25MHz crystal (1.875MHz - 20MHz): 0.41ps (typical)
  • Full 3.3V supply mode
  • 0°C to 70°C ambient operating temperature
  • Available in lead-free (RoHS 6) package




Design & Development