Hi all,

    We have built our prototype following the indications form the datasheet and the circuit example but it does not work, there is no Loop Lock and the HMC699 gets very very hot. The system must lock to 5920MHz, we asked for the programming registers…

  • RE: HMC699 Programming Registers

    Hi Marty,

    I have news about this design, sorry for being offline too much time.

    Regarding the VCO we used you are right, we are working very close to the AD797 limits but we could not afford +15V power supply.

    The VCOs are working outside the datasheet…

  • RE: What is the phase noise of HMC439 at 10Hz offset for 10 MHz pdf?

    Hi Mustafa,

    The alternatives to the HMC440, which include LD, INV, and internal 200 ohm pull ups would be the HMC4069, HMC698, HMC699.  Each one has similar performance, just different divide ratios, so pick the one that suits your application.


  • RE: HMC699 Differential active loop filter help

    Hi Dan,

    A healthy reference signal would be a square wave at +5dBm without any strange edge perturbations.

    The HMC699 will operate at 10MHz reference.  One thing to check is the series capacitor on the REF input.  At 10MHz input, you are going to want…

  • RE: HMC3716 PFD in adiSimPLL

    Hi there,

    Please reference the EZ post below. The documents referred apply to all HMC PFD / INT PLL products including the HMC439, HMC440, HMC3716, HMC4069, HMC698 and HMC699.


    Best Regards,


  • Re: Simulation models for HMC699 (PLL) with HMC583 (VCO)

    Hi Huangzeyan,

    Thank you very much for your useful answer.

    I have still a couple of questions:

    1) Which is the best opamp you may suggest to keep the phase noise as low as possible?

    2) I am missing the reason why the phase detector gain is set to…

  • RE: Phase Detector

    Hi Sai,

    I'm not aware of a Phase Frequency Detector (anywhere) with a higher input frequency than the ones I recommended. You can consider adding a prescaler before the HMC469 or HMC3716 to reduce the input frequency and keep 'N' small or consider…

  • RE: 锁相环芯片芯片底噪问题


  • Equivalent Hours of HMC764LP6CE & HMC783LP6CE

    Dir Sir,

    I would like to know the equivalent hours of HMC764LP6CE & HMC783LP6CE. I cnn't find the information in the attached Reliability Report. How can I calculate that value?

    Best regards,