Noise Handling in Capacitive Touch Sensors

摘要

In a capacitive sensor of the type having X electrodes which are driven and Y electrodes that are used as sense channels connected to charge measurement capacitors, signal measurements may be made by driving the X electrodes to transfer successive packets of charge to the charge measurement capacitors. An additional noise measurement may be made by emulating or mimicking the signal measurement, but in certain embodiments without driving the X electrodes. The packets of charge transferred to the charge accumulation capacitor may be indicative of noise induced on the XY sensing nodes. These noise measurements can be used to configure post-processing of the signal measurements.