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ADS127L11: TINA-TI Reference Design(SBAM467.TSC) : What is VOUT ?

Daisuke Yamamoto
Prodigy 40 points
Part Number: ADS127L11
Other Parts Discussed in Thread: TINA-TI, , REF6225, REF6241, REF6230

Hi !

I'm using ADS127L11 TINA-TI Reference Design(SBAM467.TSC).

What is the VOUT ?

I ran a transient analysis.

I thought the envelopes for VOUT, Vin-csh and Vdiff would be the same.

That was true when the reference voltage was 2.5V(REF6225).

I changed REF6225 to REF6230 or REF6241.

Then the envelopes weren't the same.

Is there something wrong with my idea?

Best regards,

  • 0
    TI__Mastermind 36230 points

    Hello Yamamoto-san,

    Vout is defined as:

    Vout=(AINP-AINN)/(REFP-REFN)*VREFi

    Vinput=(AINP-AINN) is the differential input voltage

    Vref=(REFP-REFN) is the differential reference voltage

    VREFi is a scaling factor, and is set to the ideal reference voltage (non-loaded version of Vref)

    Based on your images, I do not think you adjusted the value of VREFi, which needs to change to approximately 3V when using REF6230 and 4.096V when using REF6241.

    The correct voltage for VREFi can be found by running a 'DC Analysis -> Calculate nodal voltages', and using the simulated output voltage of the REF62xx (VREF) for VREFi.

    Regards,
    Keith Nicholas
    Precision ADC Applications

  • 0 in reply to Keith Nicholas
    Prodigy 40 points

    Hello Keith-san !

    As you say, I didn't adjust VREFi.

    Thank you very much.



    Best regard,

    Daisuke