AN2970原理电容式触摸和接近传感技术

AN2970原理电容式触摸和接近传感技术

AN2970
Application note

Principles of capacitive touch and proximity sensing technology

The objective of this document is to present the principles of capacitive sensing and charge
transfer used in STMicroelectronics STM8T and STM8TS capacitive sensors. All devices
can be configured in touch or proximity sensing.




1 Capacitive sensing overview

1.1 Sensing electrode capacitance
A capacitance exists between any reference point relative to ground as long as they are
electrically isolated. If this reference point is a sensing electrode, it helps to think of it