Patent ID: 8773366

Claim:
A touch sensitive apparatus, comprising: a touch sensitive device having a plurality of drive electrodes and a plurality of receive electrodes, wherein the drive electrodes are capacitively coupled to the receive electrodes; and a touch measurement circuit configured to identify, in response to changes in capacitance via signals carried by the receive electrodes, one or more temporally overlapping touch events on the touch sensitive device, the touch measurement circuit further configured to: receive a periodic receive signal carried by at least one of the receive electrodes, receive a triangular periodic threshold signal having a frequency that is an integer multiple of a frequency of the periodic receive signal, compare the periodic receive signal to the triangular periodic threshold signal during a sampling window, determine a length of time during the sampling window that the periodic receive signal amplitude satisfies the threshold signal amplitude, and identify a touch event based on the length of time that the periodic receive signal amplitude satisfies the threshold signal amplitude.