Looking at a real application case, that there are four sensing channels. Those four channels, depending on the length of the copper traces and on the size and shape of the copper pad, will have an initial intrinsic capacitance, so that the controller will “see” a certain capacitance value. Remember that the only thing that the controller “sees” is capacitance so that whenever connected to a copper pad, through a trace, it will see a capacitance there. Going back to the four channels here, each one of them has a certain amount of initial intrinsic capacitance. Looking at the shaded area, which represents the dynamic range of the device, there are two cases in which, like with the first channel on the left, the intrinsic capacitance is outside the dynamic range, and thus it cannot be measured.  By adjusting the internal reference capacitance, the dynamic range window can be shifted up to include the channel with the highest intrinsic capacitance. What happens, though, is that now the fourth channel is missing because it is below the dynamic range window, and the second channel is marginal. To fix this, capacitance is added to the second and forth channel (the yellow areas) to re-equalize the intrinsic capacitance and to bring all channels as close as possible to each other, and within the dynamic range. Therefore, the net effect is that all of the channels fall within the dynamic range window and all of them are close in capacitance.