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TPS50601A-SP: Error Amplifier Characteristics for worst-case regulation analysis

Steve Widener
Genius 10275 points
Part Number: TPS50601A-SP

Do we have any guidance on the error amplifier offset voltage and input bias currents? These are needed for worst-case analysis.

If the worst case offset is included within the Vref spec - that would be sufficient. There is a figure 10 in the current datasheet that mentions offset vs the SS pin  - that seems pretty high @ 10mV-30mV over temperature - Is that the offset referred to Vfb as well?

For the input bias current - we mention in section 7.3.3 that there is a Vsense input current and that the divider resistors should not be too high in value to minimize the impact of that current but we don't provide a max value - do we have any guidance for this?

  • 0
    TI__Genius 14540 points

    HI Steve,

    Do we have any guidance on the error amplifier offset voltage and input bias currents? These are needed for worst-case analysis.If the worst case offset is included within the Vref spec - that would be sufficient.

    [CY] yes, VREF spec includes offset voltage an bias current variation.

    There is a figure 10 in the current datasheet that mentions offset vs the SS pin  - that seems pretty high @ 10mV-30mV over temperature - Is that the offset referred to Vfb as well?

    [CY]  This figure is simply to show how the voltage on the soft start pin will track the VSENSE voltage during soft start.  This figure says nothing about steady state operation.

    For the input bias current - we mention in section 7.3.3 that there is a Vsense input current and that the divider resistors should not be too high in value to minimize the impact of that current but we don't provide a max value - do we have any guidance for this?

    [CY]  All characterization, and our EVM, were tested with RTOP of 10kohms.  We recommend using RTOP = 10kohms to achieve similar results.

  • 0 in reply to Christian Yots
    TI__Genius 10275 points

    Do we have a rough order of magnitude for the input bias current - this has come up again.

  • 0 in reply to Steve Widener
    TI__Genius 14540 points

    I don't have any information on the input current to the e/a.  Let me ask if design has anything and get back to you.

    Thanks

    Christian