MSP430FR2675: CapTIvate Supply Breakdown Problem

Tool/software:

Hello,

in my applicatation are unfortunately voltage breakdowns in the supply voltage of the MSP430FR2675.
So, when this voltage breakdowns occur, it leads to a touch detect of the CapTIvate system.
I know the reason of this. It's because I use the option DVCC enable. And the voltage breakdowns leading to a lower charge of the touch probe.

I have a couple of questions regarding this topic:

1. How big is the effect of DVCC charge enable at EMC immunity tests (conducted BCI and radiated ALSE)?
   Disabling this setting solves the problem. But there are high EMC requirements for the application.
   I will check that in EMC laboratory, but some hints to this were helpful.
2. I have another idea to solve the problem. DVCC charge enable remains active.
   Now I configurate a second CapTIvate channel on a not connected pin. At this channel I activate the 5.5pF reference capacitor.
   (I measured the channel capacity based on this document: /cfs-file/__key/communityserver-discussions-components-files/166/2084.captivate_5F00_refcap.pdf
   It's ~7,2pF. Total: ~12,7pF).
   At this second (reference) channel the capacitance should stay the same(except through temperature), because there is nothing connected. The only change comes from voltage changes, because of Q=C*U.
   When there is now a voltage drop, this leads to a negative touch at the touch channel. The touch channel recalibrates to the lower voltage level.
   When the voltage now rises again, it leads to a touch event. And for the second reference channel, it also leads to a "touch" event (due to the voltage increase). And now I can combinate this in code and avoid a touch event at the touch channel and recalibrate this channel to the new higher voltage level. This works.
   1. Have you any experience with this? Can this method lead to problems?
      Is this not connected pin with this small capacitance more sensitive to EMC?
      The documentation of the CapTIvate HW system is not very detailed.
   2. When I configure this setup with the reference channel to a different block like the one of the touch-channel,
      it leads to an MAX-Count error at the touch channel (??) as soon as I activate the reference capacitor at the reference channel.
      But why? Is this an hardware problem? I do this on a different channel. And it doesn't look like the value of the touch channel exeeds the error threshold.
      But when I do it on the same block like the touch channel, the problem doesn't occur.
      Another option to solve this is, to lower the Conversion Count and Conversion Gain.

But I will also look into hardware direction if it's possible to solve the problem with the voltage breakdowns.

Thanks for your help.

Best regards.