Features and Benefits

  • Low Noise Fractional-N PLL with Integrated VCO
  • No Δ-Σ Modulator Spurs
  • 18-Bit Fractional Denominator
  • –226 dBc/Hz Normalized In-Band Phase Noise Floor
  • –274 dBc/Hz Normalized In-Band 1/f Noise
  • –157 dBc/Hz Wideband Output Phase Noise Floor
  • Excellent Integer Boundary Spurious Performance
  • Output Divider (1 to 6, 50% Duty Cycle)
  • Output Buffer Muting
  • Reference Input Frequency Up to 425MHz
  • Fast Frequency Switching
  • FracNWizard Software Design Tool Support

Product Details

The LTC6948 is a high performance, low noise, 6.39GHz phase-locked loop (PLL) with a fully integrated VCO, including a reference divider, phase-frequency detector (PFD), ultralow noise charge pump, fractional feedback divider, and VCO output divider.

The fractional divider uses an advanced, 4th order ΔΣ modulator which provides exceptionally low spurious levels. This allows wide loop bandwidths, producing extremely low integrated phase noise values.

The programmable VCO output divider, with a range of 1 through 6, extends the output frequency range.


  • Wireless Basestations (LTE, WiMAX, W-CDMA, PCS)
  • Microwave Data Links
  • Military and Secure Radio
  • Test and Measurement

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (5)

Software & Systems Requirements

Evaluation Software


FracNWizard is used to communicate with the LTC6947 and LTC6948 synthesizers. It uses the DC590 controller to translate between USB and SPI-compatible serial communications formats. It also includes advanced PLL design and simulation capabilities.

Tools & Simulations


Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits.


IBIS Models

Design Tools


ADIsimPLL enables the rapid and reliable evaluation of new high performance PLL products from ADI. It is the most comprehensive PLL Synthesizer design and simulation tool available today. Simulations performed include all key non-linear effects that are significant in affecting PLL performance. ADIsimPLL removes at least one iteration from the design process, thereby speeding the design- to-market.

Product Recommendations

LTC6948 Companion Parts

Recommended Related Parts

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.


LTC6948 Discussions

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The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

Price Table Help


Evaluation Boards Pricing displayed is based on 1-piece.
Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.