Capacitive switch having high accuracy

A capacitive switch, comprising:

• a drive circuit configured to output a drive signal to a first circuit path and a second circuit path;
• a capacitive detection circuit electrically connected to the first circuit path;
• a capacitive reference circuit electrically connected to the second circuit path;
• and
• an identification unit comprising a first input terminal and a second input terminal, wherein
• the first input terminal is coupled to the first circuit path at a first time to receive a first detection signal generated by the capacitive detection circuit and coupled to the second circuit path at a second time to receive a second detection signal generated by the capacitive reference circuit,
• the second input terminal is coupled to the second circuit path at the first time to receive a third detection signal generated by the capacitive reference circuit and coupled to the first circuit path at the second time to receive a fourth detection signal generated by the capacitive detection circuit, and
• the identification unit is configured to identify a first phase shift between the first detection signal and the third detection signal, and identify a second phase shift between the second detection signal and the fourth detection signal.

A capacitive switch, comprising:

• a drive circuit configured to output a drive signal to a first circuit path and a second circuit path;
• a multiplexer,
• a plurality of capacitive detection circuits, one of the plurality of capacitive detection circuits being configured to be coupled to the first circuit path via the multiplexer at a first time to generate a first detection signal, and coupled to the second circuit path via the multiplexer at a second time to generate a second detection signal;
• a capacitive reference circuit configured to be coupled to the second circuit path at the first time to generate a third detection signal, and coupled to the first circuit path at the second time to generate a fourth detection signal;
• and
• an identification unit electrically connected to the first circuit path and the second circuit path, and configured to identify a first phase shift between the first detection signal and the third detection signal and identify a second phase shift between the second detection signal and the fourth detection signal.