3.3 CFG2 (Touch Sensitivity)

CFG2 determines the sensitivity of the touch sensor. A thicker touch cover, smaller sensor, or nearby ground-referenced conductors require higher sensitivity settings. Sensitivity does not affect power consumption or measurement time, except in the case of a high setting which can consume extra power by triggering unnecessary wake-up events. Configuring the sensitivity so the delta on the touch sensor is approximately 50 counts is recommended.

Additionally, matching the lower sensitivity settings with a higher oversampling for robust touch sensing is recommended. Table 3-5 shows the recommended oversampling for each sensitivity setting.

Table 3-5. 
Sensitivity Configuration * Minimum Recommended Oversampling (CFG1)
0-63 8
64-127 16
128-191 32
192-255 64
*Sensitivity value varies linearly from 0 to 255 based on the voltage applied on the CFG2 pin - 0 corresponds to GND and 255 corresponds to VDD.

Optional debug data can be used to tune the sensitivity. The Appendix provides the options for enabling Tune Data and viewing the required parameters.

Table 3-6. 
Input Range Sensitivity*
0V to VDD
  • Lowest at 0V
  • Increases with Voltage at CFG2
  • Highest at VDD
*Sensitivity input CFG2 is implemented as a full-scale linear input only when the Easy Tune option is disabled. Refer to the Easy Tune option for further details.