HMC451-die Drain modulaion

Hi all,

@ the datasheet HMC451-die, external bypass capacitors of 100 pF and 0.1 μF are required to Vdd1/Vdd2.

Evaluating the HMC451-die for the Drain modulation, then the cap of  0.1 μF is large.

Placing the both cap is recommended ?

Replacing or removing the cap of  0.1 μF is available for this application ?

Best Regards,


  • Hi SMcBride-san,

    Thanks for your reply.

    We will try operating the part with various value bypass caps, 100pF+xuF.

    Best regards,


  • 0
    •  Analog Employees 
    on Dec 11, 2015 2:04 AM

    Hi sss,

    The data sheet was created from data measured using assemblies that closely resembled the Assembly Diagram from the data sheet. To obtain performance like that shown on the data sheet we generally recommend that the customer's application circuit be made to resemble the Assembly diagram as closely as possible. While the bypass caps were included to help optimize operation across the entire specified 5 GHz through 20 GHz frequency range, customers sometimes find that particular bypass caps can be omitted without having negative effect on the performance at their frequencies of interest. It appears that we've measured the part without any Vdd bypass caps and not suffered problems. I don't see any notes indicating that particular caps are required for stability.

    Considering the above, I suggest that you try operating the part without the 0.1 uF bypass cap to see if it still provides acceptable performance.