Method and system for driving a capacitive sensor

2015 
A method for determining a capacitance value of a capacitive sensor begins by applying a sensor signal (Vx) to the capacitive sensor. The sensor signal (Vx) includes a number of charge-discharge pulse pairs distributed over a first period of time (T/N), with each pulse pair having a different pulse period. The method then proceeds by accumulating a number (N) of samples of a reference voltage (Vs) measured across a reference capacitor (Cs) that is coupled to the capacitive sensor over a second period of time (T) to produce an accumulated capacitance value (ACCUMULATED). The accumulated capacitance value (ACCUMULATED) is then divided by the number (N) of the samples to determine the capacitance value (Cx) of the capacitive sensor.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    0
    References
    0
    Citations
    NaN
    KQI
    []