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TMS320F280049: F280049: typical value of VREFHI

Sheldon He
Expert 8585 points
Part Number: TMS320F280049


Hi expert,

I noticed that the TYP value of VREFHI of F280049 device is 2.5 or 3.0. I think 3.0 is a strange value for internal reference is 2.5 or 3.3, the "VREFHI - VREFLO" 's typical value is also 3.3.

Thanks

Sheldon

  • 0
    TI__Guru 60865 points
    Hi Sheldon,

    These are operating conditions so these would be what you are providing/configuring. VREFHI in this table is therefore more geared towards external reference mode. 2.5V and 3.0V are common reference IC voltages that will fall within the allowable VREFHI range. 3.3V is also a common voltage you can get for a reference IC, but using it on this device is complicated since VDDA would need to be increased above 3.3V. We therefore don't see it as a typical use case.

    In internal reference mode 2.5V range will output 2.5V on VREFHI and 3.3V range will output 1.65V on VREFHI.

    I don't think VREFHI - VREFLO should have a typical value...agree that it doesn't really make sense.

    I'll submit for this to be clarified a bit in the documentation.
  • 0 in reply to Devin Cottier
    TI__Expert 8585 points

    Hi Devin,

    Could you check if here is an error on DS?

    Thanks

    Sheldon

  • 0 in reply to Sheldon He
    TI__Guru 60865 points
    Hi Sheldon,

    The above is correct. When the range is 0 to 3.3V the VREFHI pin has 1.65V driven OUT of it. In 0 to 2.5V range the VREFHI pin has 2.5V driven out.