Variable ADC gain in XMEGA - Analog or digital?

Go To Last Post
4 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I was thinking of using the variable gain feature on the XMega ADC, but in reading the documentation it is not clear to me whether it is truly increased analog gain, or just bit-shifting the ADC result.

Does anyone know whether there is really a 64X variable analog gain?

Thanks

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

There is a gain stage, but gain induces noise into your result, so you might be better of by using external opamps.

Hans-Christian

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I already have external gain. I was just looking for a software controllable gain.

Why would the internal gain stage be more noisy than an external gain stage?

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I am using the internal gain of the XMEGA in my Xprotolab and it works pretty good for me.