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66AK2E05: SERDES SGMII TX voltage setting

Part Number: 66AK2E05

We are working a potential SGMII issue utilizing one of the TI Keystone processors (66AK2E05) and I want to be able to update the transmitter voltage (we boot from FLASH).  Looking at one of the guides, SPRUHO3A, there is a register signal that appears to do the trick “PMA_LN_TX_VREG_LEV_O[2:0]”  however it appears to update a “regulator” output, and not the transmitter output voltage directly.  Do you have a translation between the register value setting and expected differential voltage into a 100ohm load?

Thanks

  • Hi Brad,

    Do you have a translation between the register value setting and expected differential voltage into a 100ohm load?

    We dont have exact translation between register and differential voltage into a 100ohm load.

    But, we do have information on VDDAHV (Serdes regulator voltage) and it controls Input (Vi = -0.3 to VDDAHV1+0.3V) and output voltage  (Vo = -0.3 to VDDAHV1+0.3V)

    above data derived from 66AK2E05 datasheet

    From Serdes register setting (PMA_LN_TX_VREG_LEV_O) we can control TX regulator voltage which I believe is Vo (output voltage  (Vo = -0.3 to VDDAHV1+0.3V)).

    Thanks,

    Rajarajan U