SAMD11 Touch Mode Support Ambiguity

1 post / 0 new
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hi everyone,


I'm new to using capacitive touch, and I am in the midst of designing my first PCB to take advantage of this cool tech. I have been reading through the documentation, and I caught an interesting exception in AN2934 Appendix C that seems to imply that the ATSAMD11 cannot make use of flooded X sensor designs because the X lines do not support I/O drive.


My understanding was that mutual capacitance measurements as a whole require the X lines to be driven. Does this mean that mutual capacitance is actually not supported, or does this have to do with the overall increase in capacitive load of the flooded X design? I'd be interested to hear if anyone has tried this for themselves or otherwise knows whether that appendix is accurate.