ATxmega128A3U using the ADC Calibration.

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

One of my boards fell outside our specs because of too high reading on ADCB. The init section does

	ADCB.CALL = readCalibrationByte(0x24);
	ADCB.CALH = readCalibrationByte(0x25);

I recorded the production signatures from all the boards produced an went through them to see if this board had significantly different calibration bytes than the others.

And what I found was that of the 40 signatures I checked all of them had 0x0444 as calibration byte for ADCA and ADCB. So I could as well have hard coded 0x0444?!

Are they really just for future enhancements only?

Did any of you see a different value?

Einar Sjaavik

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

This has been covered before, the values seem to be the same for all chips of a particular part number. If you change the values manually you can see that they do actually affect the operation of the ADC though, and somewhere I read an explanation of how the value is calculated. In theory you could do your own calibration with them.