摘要 |
In one embodiment, a method includes, at a first input of a comparator, receiving from an analog multiplexer one of multiple first voltages. Each of the first voltages results at least in part from an interaction between an object and an electrode of each of one or more nodes of a capacitive touch sensor. The method includes, at a second input of the comparator, receiving a second voltage across a measurement capacitor that has a first terminal coupled to the second input of the comparator. The method includes charging the measurement capacitor at least in part through a measurement resistor coupled in series to the first terminal of the measurement capacitor and monitoring an output of the comparator during the charging of the measurement capacitor. The output of the comparator changes state when the second voltage becomes approximately equal to or greater than the one of the first voltages. The method includes determining an amount of time from a start of the charging of the measurement capacitor to a change in state of the output of the comparator.
|