Active matrix capacitive touch sensor

摘要

Examples of the disclosure provide an active matrix capacitive touch sensor. In some examples, a sensor includes a plurality of primary ring oscillators, a plurality of reference ring oscillators, wherein each reference ring oscillator is associated with a respective primary ring oscillator, at least one row trace, wherein each row trace is coupled to at least one primary ring oscillator and a reference ring oscillator for each primary ring oscillator, at least one sensor column trace coupled to one primary ring oscillator for each row trace, and at least one reference column trace coupled to one reference ring oscillator for each row trace. Examples of the disclosure enable touch-screen technology to provide increased pad sensitivity and multi-touch capability in a cost-effective and scalable manner.

主权项

1. A system comprising:
a capacitive sensor comprising:
a plurality of capacitive sense pads;a plurality of primary ring oscillators, each primary ring oscillator coupled to a respective capacitive sense pad;a plurality of reference ring oscillators, each reference ring oscillator associated with a respective primary ring oscillator;a plurality of row traces, each row trace coupled to at least one primary ring oscillator and a reference ring oscillator for each primary ring oscillator of the at least one primary ring oscillator;at least one sensor column trace coupled to one primary ring oscillator for each row trace of the plurality of row traces; andat least one reference column trace coupled to one reference ring oscillator for each row trace of the plurality of row traces; and a controller configured to receive a parameter associated with the plurality of primary ring oscillators and the plurality of reference ring oscillators, and determine an operation associated with the received parameter.