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DAC7718: Power Supply Rejection Ratio (PSRR)

Chris Lange
Prodigy 70 points
Part Number: DAC7718

In the datasheet it lists:

Power-supply rejection is 0.05 LSB with a condition of AVDD = +33V to +36V.

Can you explain what that specification/condition means?

  • 0
    TI__Genius 14220 points
    Hi Chris,

    Welcome to E2E and thank you for your query. The test condition means that when AVDD is varied from +33V to +36V, the output varies by 0.05 LSB in DC.

    Hope that answers your question.

    Regards,
    Uttam Sahu
    Applications Engineer, Precision DACs
  • 0 in reply to Uttam Sahu
    Prodigy 70 points

    Hi Uttam

    Thanks for your reply.  Your response confirms what I assumed - it was just that measurement/test condition seemed a bit unusual.

    Do you have any data which might show PSRR vs. frequency?  Specifically, ripple due to a switching supply (500kHz-1.5MHz range)?

    I'm trying to determine if we need to supply the DAC with a linear regulator or if the output from our SMPS is adequate.

    Chris

  • 0 in reply to Chris Lange
    TI__Genius 14220 points
    Hi Chris,

    I understand your requirement. However, we don't have the PSRR vs frequency plot for this part.

    Regards,
    Uttam