• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 453 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DAC8565: Big Spikes in Settling-Time Figures

Chris Kimble
Intellectual 270 points
Part Number: DAC8565
Other Parts Discussed in Thread: DAC80004

In the data sheet for DAC8565, figures 44 through 47 show very large spikes in the output voltage for full- or half-scale steps.  The spikes are clipped by the figures, but exceed 8 mV.  Are these spikes produced by digital feedthrough, code-change glitch, or what?

I see similar spikes in the data sheets for other TI DACs--but I don't see them in data sheets from other manufacturers (e.g., AD).   What's going on?  How can the spikes be eliminated?   Thanks...

  • 0
    TI__Mastermind 46290 points
    Chris,

    It is hard for me to exactly describe the test setup as the data for this was collected a bit before I was involved.

    There are a few factors that could contribute to the transients observed around code changes; glitch energy, small signal settling time, and digital feed-through. All of these factors are present for all DACs, irrespective of manufacturer. How well they are documented and how much impact they carry of course vary from part to part. If you have a specific part you are comparing the DAC8565 against, maybe I can help advise.

    Being a string-DAC the DAC8565 should have somewhat minimal glitch energy though the signature can exist nonetheless. We can either offer help collecting this data via bench measurements with a test setup that is known to the current team and/or analysis against other devices to help you make your decision.

    Also, I would suggest taking a look at DAC80004. This family integrates a circuit on the output stage specifically targeted to reduce transients associated with code transitions.