Knowledge Base Article
Answer: Sensitivity is calculated using the digital capacitive measurement result returned by the User Module, referred to as Counts. Capacitance measurement range is calculated using sensitivity.
Counts are calculated using Equation 1.
Where:
Sensitivity is calculated using Equation 2.
The upper limit of the capacitance measurement range is calculated using Equation 3.
For example, given the following User Module settings:
Sensitivity = 184.3 Counts/pF
Capacitance measurement range (upper limit) = 88.9 pF
Note: The “sensitivity” calculated above is the capacitive measurement module sensitivity, not the system sensitivity to button/sensor activation.
Note: It is not possible to measure capacitance values all the way down to zero because there will always be some parasitic capacitance, CP, and pin capacitance measured by the sensor.