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Visitor II
February 8, 2022
Solved

What's happening with the CR95HF RX resistance?

  • February 8, 2022
  • 1 reply
  • 692 views

If you look into the AN4327 CR95HF transceiver antenna tuning circuit with EMI filter you see:

0693W00000JP3eyQAD.pngI assume this means 22 pF capacity in parallel with 80 kOhm resistance. But when you open the recommended Excel sheet you see:

0693W00000JP3fhQAD.pngUntil this moment this was supposed to be 1 gOhm. And finally you open the CR95HF Datasheet to check the value and there you see this:

0693W00000JP3guQAD.pngCan anyone tell me what's the correct value finally?

    This topic has been closed for replies.
    Best answer by Brian TIDAL

    Hi,

    the value to be used is 100 kOhm as specified in the Datasheet. The value in the Excel sheet is a typo but as soon as the resistance value is very high, the impact of having 80kOhm, 100kOhm or 1GOhm on the various formulas is insignificant.

    Rgds

    BT

    1 reply

    Technical Moderator
    February 10, 2022

    Hi,

    the value to be used is 100 kOhm as specified in the Datasheet. The value in the Excel sheet is a typo but as soon as the resistance value is very high, the impact of having 80kOhm, 100kOhm or 1GOhm on the various formulas is insignificant.

    Rgds

    BT

    RDienAuthor
    Visitor II
    February 11, 2022

    Hi, Brian!

    Thanks! I've checked the infuelce and it turned out to be negligiblе just as you advised. When you are newbie and something goes wrong you tend to recheck every number you are in doubts about.

    Kind regards!