• HMC698

    I use HMC698 PLL chip and an HMC509 VCO , PFD frequency is 100MHz,  op amp is THS4031ID or AD797,but can't lock either


    in HMC698  datasheet,PFD INVERT function   CMOS compatible input control bit Logic “LOW” = NORMAL Logic “HIGH” = INVERT,what does…

  • Using HMC698 PLL with 10 MHz reference

    I'm building a PLL using HMC698, and I have to work with a 10 MHz sine wave as reference. The phase noise of the 10 MHz is -135 at 10 Hz and -155 at 100 Hz. The HMC698 datasheet doesn't have phase noise data at 10 MHz, does anyone has data on that. Also…

  • HMC698 Noise Preformance at 300 MHz Ref


    HMC698 Datasheet provides typical SSB Phase Noise @ 10 kHz offset @ 100 MHz square wave ref. and Pin = 0 dBm as -153 dBc/Hz.

    Do you have similar spec but with 300 MHz square wave ref.? Would I estimate -148 dBc/Hz @ 10 kHz offset @ 300 MHz square…

  • loop filter recommendation for HMC698 +HMC586?

    Dear Sir

    Please can you recommend a loop filter circuit for an HMC698 PLL chip and an HMC586 VCO with a feedback divider ratio of 12 and a PFD frequency of 500MHz, optimised for best integrated phase noise, integrated over 10kHz to 20MHz? Preferably…

  • 利用AD9958+HMC698产生线性调频信号


  • RE: VCO HMC508: RF/4 Output

    Hi Wolfgang,

    The HMC508 does not have the RF/4 functionality built in to the device.  The evaluation board is common to many VCO products, some of which have the RF/4 port.

    Also, the HMC698 can accept the RF/2 port from the HMC508.  The max VCO input…

  • 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: 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.


  • Questions about PLL design with HMC698LP5


    My customer are designing PLL circuit  with HMC698LP5 (PLL), HMC391LP4(VCO) and OP27 (OPAMP).

    And the ouput frequency are 3.9GHz or 4.05Ghz and the reference frequency is 50MHz.

    Q1) when they implement a charge pump  of HMC698, can they implement…

  • 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…