Abstract: The identification of low noise stimulation frequencies for detecting and localizing touch events on a touch sensor panel is disclosed. Each of a plurality of sense channels can be coupled to a separate sense line in a touch sensor panel and can have multiple mixers, each mixer using a demodulation frequency of a particular frequency, phase and delay. With no stimulation signal applied to any drive lines in the touch sensor panel, pairs of mixers can demodulate the sum of the output of all sense channels using the in-phase (I) and quadrature (Q) signals of a particular frequency. The demodulated outputs of each mixer pair can be used to calculate the magnitude of the noise at that particular frequency, wherein the lower the magnitude, the lower the noise at that frequency. Several low noise frequencies can be selected for use in a subsequent touch sensor panel scan function.

Abstract: The automatic calibration of a sensor panel is disclosed by varying the amplitude of an input stimulus Vstim to simulate a full-touch condition and calibrating each pixel of the sensor panel in accordance with the difference between the simulated full-touch condition and a baseline full-touch condition. To accomplish this, a baseline full scale output FS_targ_cal can be measured at during pre-delivery calibration for each pixel using a test fixture capable of applying a no-touch to full-touch condition given a nominal Vstim. A full-touch condition can then be emulated for each pixel by lowering Vstim until the current full scale output FS_targ_current equals FS_targ_cal, and determining the Vstim value Vstim_cal at that point. During field calibration, Vstim_cal can be applied to each pixel to simulate a full-touch condition, and FS_targ_current can be obtained and compared against FS_targ_cal.

Abstract: The use of multiple stimulation frequencies and phases to generate an image of touch on a touch sensor panel is disclosed. Each of a plurality of sense channels can be coupled to a column in a touch sensor panel and can have multiple mixers. Each mixer in the sense channel can utilize a circuit capable generating a demodulation frequency of a particular frequency. At each of multiple steps, various phases of selected frequencies can be used to simultaneously stimulate the rows of the touch sensor panel, and the multiple mixers in each sense channel can be configured to demodulate the signal received from the column connected to each sense channel using the selected frequencies. After all steps have been completed, the demodulated signals from the multiple mixers can be used in calculations to determine an image of touch for the touch sensor panel at each frequency.

Abstract: Embodiments of the present invention are directed to processing an incoming signal by using a demodulation signal, while controlling the phase of the demodulation signal in relation to the incoming signal. The incoming signal can be processed by being mixed with the modulation signal at a mixer. The mixing may thus cause various beneficial modifications of the incoming signal, such as noise suppression of the incoming signal, rectification of the incoming signal, demodulation of the incoming signal, etc.

Abstract: A sensor panel device that can generate and use a stimulus signal having multiple different waveforms for detecting events on or near the sensor panel is disclosed. Among other things, such a stimulus signal can be used to reject environmental noise present in the device. In some embodiments, the stimulus signal has multiple waveforms having different frequencies. Logic circuitry can generate representative values from output of the different waveforms applied to one or more sensing nodes in the sensor panel device. From the representative values, a final value can be generated that represents whether an event occurred at or near the one or more sensing nodes.

Abstract: A device that can autonomously scan a sensor panel is disclosed. Autonomous scanning can be performed by implementing channel scan logic. In one embodiment, channel scan logic carries out many of the functions that a processor would normally undertake, including generating timing sequences and obtaining result data; comparing scan result data against a threshold value (e.g., in an auto-scan mode); generating row count; selecting one or more scanning frequency bands; power management control; and performing an auto-scan routine in a low power mode.

Abstract: Disclosed is a system and method for providing an oscillating signal of relatively precise frequency without using a signal provided by a crystal as a reference. Disclosed is a feedback oscillator circuit configured to output an oscillating signal having a frequency defined by a reference signal. The oscillating signal can be sent to one or more circuits including at least one frequency sensitive element. The frequency sensitive element produces an output signal which depends on the frequency of the oscillating signal. A controller controls the reference signal in order to cause an attribute of the output signal to have a value within a desired range.

Abstract: Embodiments of the present invention are directed to performing boundary scanning without using a pin which is exclusively dedicated for that purpose. The boundary scan can be performed by an integrated circuit by utilizing a pin which has an alternative use during ordinary operation of the integrated circuit and the device. This pin can be connected to an analog circuit configured to sense capacitance outside of the pin. The analog circuit may also have an alternative function in normal operation of the device. During a testing mode, the analog circuit can sense a stray capacitance present at the pin. The sensed capacitance can be compared to one or more stored expected capacitance values to determine an interconnection state of the system.

Abstract: Dynamically configurable routing logic coupled between physical I/O ports and special purpose I/O associated with functions within a panel ASIC is disclosed that provide different routing configurations between the physical I/O ports and the special purpose I/O. In one routing configuration, any special purpose output can be coupled to one or more physical I/O ports, providing flexibility to route any functional I/O to any physical I/O port. In a second routing configuration, any input signal on a physical I/O port can be coupled to one or more special purpose inputs. In a third routing configuration, the input signals on a number of physical I/O ports can be configured to independently assert a single special purpose input for interrupt triggering. The dynamically configurable nature of the routing logic allows routing to be changed on the fly.

Abstract: Disclosed is a system and method for providing an oscillating signal of relatively precise frequency without using a signal provided by a crystal as a reference. Disclosed is a feedback oscillator circuit configured to output an oscillating signal having a frequency defined by a reference signal. The oscillating signal can be sent to one or more circuits including at least one frequency sensitive element. The frequency sensitive element produces an output signal which depends on the frequency of the oscillating signal. A controller controls the reference signal in order to cause an attribute of the output signal to have a value within a desired range.

Abstract: The use of one or more proximity sensors in combination with one or more touch sensors in a multi-touch panel to detect the presence of a finger, body part or other object and control or trigger one or more functions in accordance with an “image” of touch provided by the sensor outputs is disclosed. In some embodiments, one or more infrared (IR) proximity sensors can be driven with a specific stimulation frequency and emit IR light from one or more areas, which can in some embodiments correspond to one or more multi-touch sensor “pixel” locations. The reflected IR signal, if any, can be demodulated using synchronous demodulation. In some embodiments, both physical interfaces (touch and proximity sensors) can be connected to analog channels in the same electrical core.

Abstract: A system and method for autonomously scanning a sensor panel device, such as a multi-touch panel, is disclosed. In one embodiment, the system and method disables a sensor panel processor after a first predetermined amount of time has elapsed without the sensor panel device sensing any events. One or more system clocks can also be disabled to conserve power. While the processor and one or more system clocks are disabled, the sensor panel device can periodically autonomously scan the sensor panel for touch activity. Accordingly, if one or more results from the autonomous scans exceed a threshold, the sensor panel device re-enables the processor and one or more clocks to actively scan the sensor panel. If the threshold is not exceeded, then the sensor panel device continues to periodically autonomously scan the sensor panel without intervention from the processor. Furthermore, the sensor panel device can periodically perform calibration functions to account for any drift that may be present in the system.