Post Go back to editing



We have previously used the HMC625HFLP5E (now marked obsolete).

The alternative part HMC625ALP5E is mostly the same except for the addition of the ACG1 - ACG6 pins (where previously they were N/C).

The datasheet suggests these be connected to AGND with a capacitor to suit the lowest frequency of operation.

For an operating frequency of 5 to 6 GHz, are any capacitors required?

Is there anything else we need to consider before using the HMC625ALP5E as a drop in replacement?


Tom Green

  • Yes, I would suggest populating pins ACG1-6 (pins 5-10) with 100pF caps as specified in the Application circuit on the datasheet.

    The ACG pins provide device a clean AC ground path for optimal operation. Refer to Q2 and Q3 on FAQ referenced below for further guidance on picking AC grounding (ACG) caps.

    FAQ on Hittite Microwave RF/MW Amplifiers from ADI

  • Thanks for the advice so far bkamak.

    Based on the pinout of the HMC625HFLP5E, I'm guessing the ACG pins are the grounds for each of the attenuator stages and that they (within HFLP5E) the are internally decoupled within the package.

    Are you able to suggest / detail what the decoupling scheme was internally within the HFLP5E.  Does any of it still exist in the ALP5E package?

    I'm trying to evaluate just how much additional external decoupling must be added for us to use the ALP5E package?  We have an existing design that's very tight on space and don't want to make too many changes to the layout

    Thanks again,

    Tom G

  • This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

    Thank you,
    EZ Admin