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V FB characteristic of TPS7A4901.

HIRATA MITSUO
Intellectual 490 points
Other Parts Discussed in Thread: TPS7A49

I need V FB characteristic information of TPS7A4901.
In detail, the characteristic is V FB's variability and temperature.

V FB will be V ref + V err amp offset + V amp bias current*R.
Especially, I want information of V offset's variability and temperature and V ref's temperature characteristic.

  • 0
    TI__Guru 55940 points
    Hi ,

    The variability of Vref due to factors internal to the LDO are a part of the Overall accuracy of TPS7A49. To help calculate the effect of an external resistor divider on the power supply accuracy we have an application report which can be found here:

    www.ti.com/.../slva423.pdf

    Very Respectfully,
    Ryan
  • 0 in reply to Ryan Eslinger
    Intellectual 490 points
    Hi, Ryan

    Thank you for your reply and I have additional question.

    > The variability of Vref due to factors internal to the LDO are a part of the Overall accuracy of TPS7A49.

    Datasheet information looks like V ref is err amp input voltage.
    So I thought FB port voltage will add err amp's offset voltage and err amp's bias current*external R to Vref.
    However, Vref voltage equals FB port voltage ,doesn't it?

    Best regards,
    Mitsuo
  • 0 in reply to HIRATA MITSUO
    TI__Guru 55940 points
    Hi Mitsuo,

    There is a slight offset between Vfb and Vref as shown in the typical column of the Electrical Characteristics table; however, the overall accuracy of the device does include everything internal to the device. It does not include the external resistor network, but the application report shows how to calculate the effect of the external resistor network.

    Very Respectfully,
    Ryan