Atmel Qmatrix, Application Note, Page: 22 / 27

QTouch Schematic and Layout Checklist [APPLICATION NOTE]
Atmel-42094C-QTouch-Schematic-and-Layout-Checklist-ApplicationNote_072014
22
• X Lines and Y Lines are not routed near each other
The X-lines are not touch sensitive and hence their routing is not as critical. But it is important to ensure that they
are not routed near Y-lines as this may create false keys ( Figure 3-19 ). If the lines need to run together or cross
then extra care needs to be taken to avoid false keys. Some routing suggestions are illustrated in Figure 3-20 .
Figure 3-19. X and Y Lines Placed Close to Each Other Can Behave Like a Button
Figure 3-20. Tips for Minimizing Interaction Between X and Y Routing
a. 90
o
crossing
b. Separating ground trace
c. X under Ground trace d. Y under X
• X Lines and Y Lines Interconnection using Flex cables
When using Flex cables for interconnection of sense lines, group all X lines together and group Y lines together,
and then use a ground trace in between the groups. This avoids formation of stray capacitance across the closely
routed X and Y line.