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TPS65000-Q1: TPS65000-Q1 regulation accuracy

Piotr F.
Intellectual 2540 points
Part Number: TPS65000-Q1

Hi Team!

I have few questions about TPS65000-Q1 regulation accuracy:

  1. Are datasheet DCDC accuracy numbers (+/-1.5%) given for whole operating ambient temperature range (-40 / +105 degC)?

  2. To calculate DCDC accuracy, the datasheet accuracy value (+/-1.5%) needs to be combined with FB resistors accuracy – right? Anything else should be included like FB pin current or Vref drift? Are these factors already included in the +/-1.5% DCDC accuracy number?

  3. Surprisingly, I haven't found any TI document on calculating Buck DCDC output accuracy - can you recommend some?

  4. Same questions for LDOs: Are LDO accuracy given for whole temp range? Anything else to include in total LDO output accuracy than FB resistors (FB pin current?) ?
    This time I've found a TI doc on LDO terms and definitions: https://www.ti.com/lit/an/slva079/slva079.pdf - good guideline, but there is nothing on FB pin current :( 

Piotr

  • 0
    TI__Genius 10885 points

    Hi Piotr,

    1) Yes, min and max are across ambient temperature (-40 to +150 degC).

    2) Yes you need to incorporate feedback resistor error as well, where maximum feedback current is .1uA. 1.5% includes vref drift and may be most relevant to versions with fixed output voltages that use an internal voltage divider network (Figure 16 in DS).

    3) While not for bucks specifically, this document discusses similar accuracy considerations for a voltage divider network: www.ti.com/.../slva450a.pdf

    4) The accuracy provided is across ambient temperature range and specific to those conditions. Without a min and max for the FB reference, one could use the total error of 3.5% in place of the feedback tolerance when trying to estimate absolute worst case accuracy.

    Best Regards,

    Rick S.