• State
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 33 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

ADS5296A: Input oscillation issue

christopher hudson
Prodigy 10 points
Part Number: ADS5296A

Tool/software:

I have a high speed system driving the front end of the ADS5296A A2D.  I noticed some serious oscillation in the signal of my anti-aliasing filter.  I disconnected the filter from the ADC and the oscillation on my filter output went away but is still very present on the floating input of the ADC. See schematics below.  The oscillation is at the clock rate.  Is the issue due to the ADC input not being properly terminated or impedance matched?  any suggestions on how to clean this up.  the noise is somewhat common-mode on both P and N inputs, but not exactly so I'd like to figure out how to get rid of it.

  • 0
    TI__Expert 4765 points

    Hi,

    I am coming up with possible issues

    1) Because of clock Coupling  : Can you check the oscillation  without clock ? You can change clock frequency and check whether this "oscillation" frequency is changing ? When probing this signal did you properly ground the probe ground terminal.

     2) What do you mean by disconnected the filter ? When you say floating node of ADC where are you probing ?

    3) Do you see this oscillation tone t the ADC output ?