Si54x/Si56x Ultra Series™ High-Performance Crystal Oscillators    

Industry’s Lowest Jitter, Widest Frequency Range, Any-Frequency XO/VCXO Family    

Our Ultra Series™ high performance oscillators utilize our latest 4th generation DSPLL technology to provide an ultra low jitter, low phase noise clock at any output frequency up to 3 GHz. This family includes oscillators with industry-leading phase jitter as low as 80 fs (femtoseconds) for optical networking, 100G+ optical modules, broadband, data center, broadcast video, test and measurement, mil/aero and FPGA applications. These oscillators are ideal for high-performance, next generation timing applications and provide the frequency flexibility, superior reliability, and super fast lead times that system designers need. Ultra Series oscillators are available with single, dual, quad, and I2C options in industry-standard 2.5x3.2 mm, 3.2×5 mm, and 5x7 mm footprints, enabling drop-in compatibility with traditional XOs and VCXOs..

Superior Performance + Maximum Flexibility
= More Peace of Mind

  • Industry-leading jitter performance
  • Wide frequency range with < 1 ppb frequency resolution
  • Single, Dual, Quad, I2C configurations available
  • I2C supports 100 kHz (Standard), 400 kHz (Fast Mode) and 1MHz (Fast Mode Plus) update rates
  • Reduces part numbers: define 4 startup frequencies, use I2C to generate any frequency after startup
  • Excellent supply noise immunity (-80dBc Typ) ensures low jitter operation in electrically noisy systems
  • Excellent temperature and total stability (-40 to +85 °C)
  • 2.5x3.2 mm, 3.2x5 mm, and 5x7 mm footprints
  • 3.3, 2.5, 1.8V supply operation from the same orderable part number
  • Supports all popular formats: LVDS, LVPECL, HCSL, CML, CMOS, and Dual CMOS
  • Superior reliability, 100% electrical testing of every device
  • Samples available with 1-2 week lead times


  • XO only
  • 80 fs RMS Typ
  • 200 kHz - 1.5 GHz
  • 7 ppm temp stability option
  • XO and VCXO options
  • 90 fs RMS Typ
  • 200 kHz - 3.0 GHz
  • 20 ppm temp stability option

Consistent, Ultra Low-Jitter Performance
for Any-Frequency

  • Measurements collected for > 700 commonly used frequencies
  • Ultra low-jitter regardless of integer or fractional frequencies
  • Phase noise plots for specific frequencies available using our Oscillator Phase Noise Lookup Tool

Create Custom Parts Online In < 1 Minute
Get Samples in 1-2 Weeks

Click the "Customize" link in the product matrix table below or start at the Custom Oscillator Part Number Utility    

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Phase Jitter (RMS) Frequency Range Package Size (mm) Output Format(s) Stability (+/- ppm) Supply Voltage (V) Temperature Range (°C)

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Ultra Series™ Crystal Oscillators (XO)

World’s Lowest Jitter, I²C Programmable XO.

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