Product description

The CMX979 is a low-power, wideband, dual PLL and VCO, RF building block, 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.

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  • 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

Power supply requirement

  • 2.7 to 3.6 V power supply

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Design resources

EV9790 Evaluation Kit


The EV9790 is a demonstration and evaluation platform for the CMX979 Dual PLL and VCOs. The board includes all necessary voltage regulators and is operated from an external ~6V dc supply.




EV9790 User Manual







Quick set-up IF PLL – Please register or login to download

EV9790 User Manual IF PLL Quick set-up. Lock the IF PLL at 901.2 MHz.

Quick set-up RF PLL – Please register or login to download

EV9790 User Manual RF PLL Quick set-up. Locks the RF PLL @ 3.2 GHz and outputs at 1.6 GHz (divide by 2).

Knowledge Base

EV9790 Board Schematics. High resolution schematics for the EV9790. Version B03 – Please register or login to download

CMX979 Evaluation in Win OS. A GUI for evaluating the CMX979 using the EV9790 in Windows. The GUI gives direct register access or runs a simple scripting language. Please see the PE0003 User Manual for driver installation instructions. The USB driver in this package is signed and so may not be compatible with older Windows computers. Version 1.0 For a driver suitable for Windows XP, go to the PE0003 Product page and click on the Knowledge Base tab – Download

C-BUS Guides. Guides to operation and interfacing – Download

Package: Q4

40-pin VQFN

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