• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 423 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

REF5025: difference in PSRR curves for different precision voltage reference types

Ashwin Simha
Prodigy 20 points
Part Number: REF5025
Other Parts Discussed in Thread: REF3425

Hello,

This is a very basic doubt on voltage references. Some datasheets like REF5025 quote a positive db vs. frwequency curve for PSRR while others ADR366AUJZ (Analog Devices) and LT6652 (Linear Technology) show a negative db vs. frequency for PSRR. I am pretty sure that this is not an errata on the datasheet since until recently Analog Devices and Linear Technology were independently operating.

Is the PSRR curve for series and shunt precision reference look different? If so what is the reason?

Best regards

Ashwin

  • 0
    Guru 140200 points
    Hi Ashwin,

    the sign doesn't matter, only the number counts. How the different manufacturers use the sign has only to do with tradition.

    If you give a "-" then you want to tell how much of the ripple can be seen at the output. Or by other words, the PSRR is referenced to the input ripple. If you give a "+" then you want to tell, how much bigger the input ripple is than the output ripple. Or by other words, the PSRR is now referenced to the output ripple.

    Kai
  • 0
    TI__Mastermind 19370 points
    Hi Ashwin,

    Kai summarized it pretty well. Even in voltage references, TI chances the PSRR sign interchangeably. For example the REF3425 has a negative PSRR.

    -Marcoo