• HMC704 SPI Operation


    We developed a board with HMC704 as 6,5 - 7,5 GHz frequency synthesizer with 100 MHz reference, HMC505 as VCO and Inverting Loop filter.
    HMC704 is controlled by STM32F1 via SPI (HMC Mode).

    I am setting register values as follows and in the in following…

  • Reset of HMC704


    I am considering a power-on reset for the HMC704.

    Is it a problem that 3.3V power supply is "ON => OFF => OFF" while 5V power supply is applied to the HMC704?

    Best regards,

  • Phase Changing of PLL w HMC704

    Hi, guys

    There's a phenomenon that the phase is randomly 0 or 180 when the frequency hopping at same target frequency with frac-N, but constant with int-N.  Why? & How to keep constant with frac-N ?

  • HMC704 design?


    I am design a board using HMC704 Pll chip. 

    please refer to the attached Block.


    I  using USB interface board (121726-2) for HMC704 Control.

    when trying to Control  by using the usb interface board, it is said that the usb port in not connector.



  • how could i get HMC703 or HMC704 verilog demo?

    how could i get HMC703 or HMC704 verilog demo?I have used the SPi mode to control the Hmc704,but it will unlocked   occasionally after power on。so i need to read the register,but i am not skilled at verilog。

  • HMC704 unlock


    I am using HMC704 in a PLL. The frequency is single frequency, 4000MHz. Reference is 100MHz

    Based on data sheet, I have set N divider to 2 so that the variable divider gets 2000MHz.

    The unit sometime locks. But at low temperatures it does not lock…

  • RE: About HMC704 lock time unstable


    Are you measuring lock using the LD_SDO pin, or are you looking at Vtune? If you are only looking at LD pin then you should double check your lock detect window settings with the equations from page 22 & 23 of datasheet, especially since you're using…

  • HMC704 in parallel for in band phase noise 3dB improvement

    Hi, ADI experts:

    I want to use HMC704 to lock 100Mhz ref to 4Ghz, but the HMC704 phase noise floor is not enough for my application even in HiK mode.

    My target is PN=-117dBc/Hz @ 4Ghz/10Khz offset.

    So I want to use two HMC704 in parallel to improve the…

  • HMC704 IBS

    Hi all:

      i am using HMC704 and vco to generate 7.000025GHz,the PFD 100MHz, the REF 100MHz,LPF BW is 50KHz. Then i found some spurs, the spurs -30dBc@25KHz.

    1. the spurs are IBS?

    2.How to eliminate or decrease these spurs?

    Thank you for your reply!

  • 关于HMC704近端相噪和仿真值不一致的问题