CML - Radio Frequency - CMX979

The CMX979 is a low-power, wideband, dual synthesiser and VCO, supporting signal generation over a wide range of frequencies. The ‘RF’ high frequency synthesiser employs a Fractional-N design and will operate at up to 3.6GHz using a fully-integrated internal VCO. The ‘IF’ synthesiser employs an integer-N design and will operate at up to 1GHz. It has an integrated VCO requiring only an external inductor to set the fundamental frequency. Internal dividers and buffers are provided for each synthesiser/PLL allowing a wide range of frequency generation options.

Designed primarily for radio transmitters and receivers using superhetrodyne architectures, the CMX979 provides a compact solution for frequency generation requiring a minimum of external components. The CMX979 operates from a single supply voltage and is available in a small 6x6mm VQFN package.


  • RF synthesiser/PLL
    • Fractional-N 24-bit divider
    • Output range 338MHz – 3.6GHz
    • Programmable output divider
    • Fast lock function
    • Programmable charge pump current
  • IF synthesiser/PLL
    • Integer-N 14-bit divider
    • Output range 31MHz – 1GHz
    • Programmable output divider
    • 209dBc/Hz normalised phase noise
    • Integrated low noise LDO regulator
    • Flexible power saving operating modes
    • Single 2.7V to 3.6V supply
    • 1.8V digital interface supported
    • -40° to +85° operating temp. range
    • Small outline 6mm x 6mm VQFN package


  • Satellite modems
  • Custom ISM band modems
  • Wireless data links
  • CATV equipment
  • General purpose RF use

Supply Requirement:

  • 2.7 to 3.6 V power supply