• VCO hmc778替代产品





  • HMC778 RFOUT coupling cap (why 100 pF)?

    Hello ADI,

    Why was a 100 pF coupling cap used on the HMC778 RFOUT on the eval board schematic?  Since this part operates around 10 GHz I would have expected that a much smaller coupling cap would be used.  I swept a 100 pF, C0G 0402 cap at 10 GHz and the…

  • HMC778

    Hi All 

    Is it possible to improve the Phase Noise of the HMC778. (9.6 - 10.8 GHz)

    The current configuration is -106/-102 dBc/Hz @ 10 kHz. I'm looking for at least for a Phase Noise of -110 dBc/Hz.

    If not, Is there maybe an alternative device i can…

  • HMC778:Output signal performed bad

    Hi! I had some problems when using HMC778. Now i think i have set right values to configure HMC778, and the ouput signal seemed to be locked. But the quality was very bad and i will attach a spectrum picture of it. I have no idea what can cause this issue…

  • HMC778 How to mute output signal and force LD low?

    HMC778 after powerup (without registers programming) working on maximum VCO Output Frequency (about 10.9 GHz) and LD is unstable: sometimes LD=1 or LD=0, or fastly switching between 1 and 0.

    How to disable output and force LD=0 (in other words: how to…

  • HMC778 RF output power too low

    Refer to HMC778 evaluation board, I have made a PLL board and its schematic is shown below. The RF output power of hmc778 should be 9dbm@10GHz. And I want to get 9-5+14=18dbm output power through a attenuation network and PA hmc441.

    The problem is the…

  • About HMC778 PIN: VCCVCO


    I have noticed that in the schematic of evolution board of HMC778, there is an option for pin "VCCVCO2". Shown as following.

    I want to ask the function of "JP2" or is there any difference if I provided 5V to VCCVCO2 or not?…

  • HMC778 Evaluation Board some time the output power drops to -9dbm


    We are using the HMC778 Evaluation board.  we have observed that some time we get  +9dbm output from the synthesizer board.  But many time we have seen that it drops to -9dbm.

    Then we reset the synthesizer board  many times and again some time the…

  • HMC778 SPI Programming

    Dear Sir,

    I am using HMC778 to generate single frequency output at 10.8 GHz. I am using SPI in HMC mode to program the device and the base XTAL frequency to HMC778 is 100 MHz. Can I get the register sequence and value for this configuration ?? 


  • HMC778 Integer Mode Freq Tuning Equation

    As shown in Functional Diagram VCO Freq always divided by 2 and then optionally can be divided by 2 again. Then equation 5 is not correct. There is no addition "divide by 2". Am i right?

    The main question is i am trying to setup HMC778 in integer…