Multi-phase scanning

An apparatus comprising:

• phase circuitry configured to simultaneously apply a same drive signal, for at least a period of time, to each of a plurality of transmitter electrodes of a touch panel during a plurality of scanning stages, wherein:
• the plurality of scanning stages occur while the phase circuitry applies the same drive signal, the phase circuitry configured to provide phase modulation of the same drive signal applied to the plurality of transmitter electrodes according to the plurality of scanning stages;
• the phase circuitry is configured to drive a first phase of the same drive signal on a first one of the plurality of transmitter electrodes during a first scanning stage of the plurality of scanning stages, and during the first scanning stage, the phase circuitry is configured to drive a second phase of the same drive signal on a second one of the plurality of transmitter electrodes;
• the first phase of the same drive signal comprises an in-phase drive signal;
• the second phase of the same drive signal comprises an opposite phase drive signal;
• and
• the phase circuitry is configured to select a pseudorandom sequence having a number of one and negative one values, wherein a number of values in the pseudorandom sequence is equal to a number of the plurality of transmitter electrodes, wherein the one values correspond to the in-phase drive signal and the negative one values correspond to the opposite phase drive signal, the phase circuitry configured to applying either the in-phase drive signal or opposite phase drive signal to the plurality of transmitter electrodes according to the pseudorandom sequence, rotate the pseudorandom sequence, and apply either the in-phase drive signal or opposite phase drive signal to the plurality of transmitter electrodes according to the rotated pseudorandom sequence;
• and
• sensing circuitry configured to receive sense signals from a plurality of receiver electrodes, wherein each sense signal represents capacitances formed between the plurality of transmitter electrodes and a respective one of the plurality of receiver electrodes, responsive to the same drive signal and to detect a presence of an object on the touch panel.

A system comprising:

• a signal source configured to generate a carrier signal;
• phase circuitry configured to receive the carrier signal and then drive the carrier signal at different phases simultaneously for at least a period of time, on each of a plurality of transmitter electrodes of a touch panel according to a plurality of scanning stages, wherein
• the plurality of scanning stages occur while the phase circuitry drives the carrier signal;
• the phase circuitry is configured to drive a first phase of the same drive signal on a first one of the plurality of transmitter electrodes during a first scanning stage of the plurality of scanning stages, and during the first scanning stage, the phase circuitry is configured to drive a second phase of the same drive signal on a second one of the plurality of transmitter electrodes;
• the first phase of the same drive signal comprises an in-phase drive signal;
• the second phase of the same drive signal comprises an opposite phase drive signal;
• and
• the phase circuitry is configured to select a pseudorandom sequence having a number of one and negative one values, wherein a number of values in the pseudorandom sequence is equal to a number of the plurality of transmitter electrodes, wherein the one values correspond to the in-phase drive signal and the negative one values correspond to the opposite phase drive signal, the phase circuitry configured to applying either the in-phase drive signal or opposite phase drive signal to the plurality of transmitter electrodes according to the pseudorandom sequence, rotate the pseudorandom sequence, and apply either the in-phase drive signal or opposite phase drive signal to the plurality of transmitter electrodes according to the rotated pseudorandom sequence;
• and
• sensing circuitry configured to receive sense signals from a plurality of receiver electrodes, wherein each sense signal represents capacitances formed between the plurality of transmitter electrodes and a respective one of the plurality of receiver electrodes, responsive to carrier signal driven at the different phases and to detect a presence of an object on the touch panel.