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ADS122C04: About the relationship between AVDD and VREF

Junya Kato
Expert 1635 points
Part Number: ADS122C04

Hello Team,

I'm planning to supply 3.0V to AVDD and REF separately.
In that case, there is a possibility that "AVDD < Vref" may occur due to voltage variation of AVDD.
Is it acceptable? If it is acceptable, please tell me how far the voltage difference is possible.
As described in the datasheet, is "AVDD > Vref" mandatory?
By the way, AVSS is 0V.

Best regards,
Kato

  • 0
    TI__Guru** 113765 points
    Hi Kato-san,

    The answer to your question is in the table you provided (section 6.3 of the datasheet). The absolute recommended positive reference voltage is AVDD + 0.1V. The absolute maximum, as given in section 6.1 of the ADS122C04 datasheet, is AVDD + 0.3V.

    Generally you would want a low-noise and stable supply for AVDD as well as the reference, so why not use the same supply for both? In fact, the reference mux allows for just such of a connection (AVDD/AVSS).

    Best regards,
    Bob B
  • 0 in reply to Bob Benjamin
    Expert 1635 points
    Hello Bob-san,

    Thank you for always answering politely. I will consider it.

    Best regards,
    Kato