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ADS4245EVM: Making ADS4245EVM work with DC and low frequency voltages.

Rahul Sawant
Prodigy 20 points
Part Number: ADS4245EVM
Originally the ADS4245EVM  board is configured to work for only ac signals above 0.5 MHz. I wanted it to work for lower frequencies also. Starting from DC.
So I made a following change in the circuit.
However the signal seen by the ADC is getting distorted.
The blue is curve read by the ADC. It should be a simple triangle wave as shown by yellow curve.
Any reason this might be happening?
I see the same distortion for frequencies from 1 Hz to 1MHz.
  • 0
    TI__Guru* 91947 points

    Rahul,

    The analog inputs must be biased to 0.95V. You have removed the bias connection from the ADC by removing R27 and R28. You need to make sure the swing on the two inputs are symmetrical and swing no more than 0.95V +/- 0.5V. See section 9.3.1 of the data sheet.

    Regards,

    Jim