38.5.1.2 CVD Mutual Sensing

The mutual capacitance measurement is performed between two lines, namely transmit (TX) and receive (RX). The mutual TX line is driven in sync with the charge-sharing phase of self-cap measurement resulting in charge contribution from the TX pin. The resulting charge distribution between S&H Cap and the RX line is a combination of charge accumulated on S&H Cap and charge contributed by driving the TX line.

Figure 38-2. CVD Mutual Sensing Waveform
Figure 38-3. Typical Mutual Cap Sensor Arrangements