Multipoint touch surface controller

摘要

A multipoint touch surface controller is disclosed herein. The controller includes an integrated circuit including output circuitry for driving a capacitive multi-touch sensor and input circuitry for reading the sensor. Also disclosed herein are various noise rejection and dynamic range enhancement techniques that permit the controller to be used with various sensors in various conditions without reconfiguring hardware.

主权项

1. A charge amplifier for detecting changes in capacitance at one or more touch nodes of a touch sensor panel, comprising:
an operational amplifier having a non-inverting input terminal, an inverting input terminal coupled to the one or more touch nodes, and an output terminal; a feedback capacitor connected between the output terminal and the inverting input terminal, wherein the feedback capacitor is programmable to take on a range of values; and a feedback resistor connected between the output terminal and the inverting input terminal, wherein the feedback resistor is programmable to take on a range of values, wherein a capacitance of the feedback capacitor is set on a per-node basis using a value having a component adjustable on a row by row basis.