Capacitive proximity sensing is a key feature for many smart devices and equipment. In this application note, we review several important advantages of our new capacitive sensing chip FDC2x1y, which is based on an LC resonator. They include its high resolution, immunity to electro-magnetic interference (EMI), and tolerance of high offset capacitance. We also provide some guidelines in sensor design by characterizing the relationship between detection range and sensor size, using a square copper plate as the sensor. The simplicity and flexibility of the sensor allows it to be easily incorporated into various systems that require proximity sensing.
Texas Instruments’ family of LC-based capacitive sensors include the FDC2214, FDC2212, FDC2114, and FDC2112.