Abstract: A source driver for a display, including: a current source that provides an approximately constant current; and multiple channels coupled to multiple source electrodes and including multiple digital to analog converters (DAC), each DAC including: a voltage source that applies a voltage to a source electrode based on the approximately constant current provided by the current source; and a control unit having circuitry that: inputs a digital value; and terminates, based on the digital value, charging of the voltage source by the approximately constant current.

Abstract: An example processing system for a display device includes driver circuitry and a control circuit. The driver circuitry is coupled to a plurality of source line nodes in the display device, each source line node of the plurality of source line nodes coupled to a plurality of subpixel columns through a demultiplexer having a plurality of switches. The control circuit is coupled to each demultiplexer. The control circuit is configured to operate each demultiplexer in a first mode by successively activating the respective plurality of switches, and in a second mode by concurrently activating the respective plurality of switches.

Abstract: A source driver including: a current source that provides an approximately constant current; a channel coupled to a source electrode and including a digital to analog converters (DAC), the DAC including: a voltage source that applies an output voltage to the source electrode based on the approximately constant current provided by the current source; and a control unit having circuitry that: inputs a digital value; and terminates, based on the digital value, charging of the voltage source by the approximately constant current; and a calibration unit having circuitry that: generates a comparison between a test voltage applied by the voltage source with a target voltage; and modifies the approximately constant current based on the comparison.

Abstract: Embodiments described herein include a display device having a capacitive sensing device, a processing system and a method for providing an adaptive low-power mode. In one embodiment, the method includes generating a reference voltage with one or more reference voltage generators while a display device is in a grayscale mode. The method also includes driving subpixels in the grayscale mode with the reference voltage. The method further includes shutting down the one or more reference voltage generators and driving subpixels in a low power, binary mode with a VCOM voltage based on positive and negative supply rails.

Abstract: An LC display driver IC suitable to drive source voltage signals to a liquid crystal display, and including an LCD source driver that can convert video image data into a selected one of N gamma-compensated analog gray-level source voltages corresponding to a respective one of the N gamma-compensated reference voltages, and drive out the selected gamma-compensated source voltage.

Abstract: Embodiments described herein synchronize a switching frequency of switched power supplies with timing events associated with updating a display screen or performing touch sensing. For example, a touch event may be the time needed for a touch controller to scan a plurality of sensing electrodes. Because noise is introduced each time switched power supplies switch between different stages, the touch controller may instruct a power management controller to switch between the stages (i.e., adjust the switching frequency) at the same time during each touch event. Even though the switched power supplies are permitted to introduce noise into the touch system, the noise happens at the same time during each touch event. Accordingly, the effect of the noise is the same for each touch event and is cancelled out. A similar process may be used for synchronizing the switching frequency to display events.

Abstract: Embodiments include a method (as well as an input device and processing system) that includes driving a display signal onto at least one of a plurality of display electrodes for updating a display, and driving an input sensing signal onto at least one of a plurality of sensor electrodes, where driving the input sensing and driving the display signal at least partially overlap in time. The method further includes receiving, using a coupling electrode disposed proximate to the at least one display electrode, a coupling signal that represents an effect of a signal on at least one of the display electrodes, on a signal on at least one of the sensor electrodes, acquiring resulting signals with at least one of the sensor electrodes, and adjusting the resulting signals based on the coupling signal.

Abstract: An apparatus is provided, which includes a driving circuit. The driving circuit includes a gamma reference source and a liquid crystal display (LCD) source driver circuit. A first resistor string is provided. A plurality of digital-to-analog converters (DACs) are provided, where each DAC is coupled to the first resistor string. An output circuit having a second resistor string is provided so as to output a plurality of reference voltages. The LCD source driver circuit is coupled to the output circuit of the gamma reference source. The source driver is configured to receive the plurality of reference voltages, wherein the plurality of reference voltages are arranged in a first sequence during a positive polarity cycle and are arranged in a second sequence during a negative polarity cycle. The fifth sequence is an inverse of the fourth sequence.

Abstract: A voltage drive circuit is constructed by stacking NMOS and PMOS transistors to provide high voltage levels with an output voltage swing greater than the breakdown voltage of the individual transistors used to build the voltage drive circuit. The voltage drive circuit may include a series stack of capacitors connected between gates of the stacked PMOS and NMOS transistors. The capacitive loading causes the gate signals to change more synchronously. Errors in timing for these gate signals, which would otherwise result in damage from exceeding the breakdown voltage across a pair of terminals of one of the NMOS and PMOS transistors, are mollified.

Abstract: Embodiments of the invention generally provide an input device that simultaneously transmits a multiplexed signal across two or more transmitter electrodes used in touch detection. The multiplexed includes two or more component signals that are transmitted on respective electrodes (or channels). The component signals are then decoded and correlated to indicate a positional location of an input object. Various multiplexing schemas—e.g., code division multiplexing, frequency division multiplexing, orthogonal frequency division multiplexing, and the like—may be used to generate the multiplex signal and then demultiplex the received results.

Abstract: Embodiments of the invention generally provide an input device that includes one or more source drivers that are coupled to a display screen. Specifically, one of the source drivers may be coupled to a plurality of source lines (or column lines) on the display screen which the source driver uses to set voltages associated with one or more sub-pixels that determine the color displayed by the pixel. When driving voltages onto subsequent source lines, the input device may precharge the source driver using a latent voltage stored on the source lines. That is, if the source line was previously driven to a particular voltage by the source driver, the input device uses that latent voltage to precharge the output of the source driver to the same voltage. The source driver may then adjust its output to a desired voltage and drive the desired voltage onto the source line and sub-pixel.

Abstract: Embodiments include a method (as well as an input device and processing system) that includes driving a display signal onto at least one of a plurality of display electrodes for updating a display, and driving an input sensing signal onto at least one of a plurality of sensor electrodes, where driving the input sensing and driving the display signal at least partially overlap in time. The method further includes receiving, using a coupling electrode disposed proximate to the at least one display electrode, a coupling signal that represents an effect of a signal on at least one of the display electrodes, on a signal on at least one of the sensor electrodes, acquiring resulting signals with at least one of the sensor electrodes, and adjusting the resulting signals based on the coupling signal.

Abstract: A display driver maps a selection code (a digital signal) to a reference voltage which is then used to produce a particular intensity of the radiation emitted from a pixel on a display screen (e.g., a LCD display). This mapping may be performed by one or more DACs in the display driver. However, instead of transmitting all of the different possible reference voltages to the DACs, only a subset of the reference voltages are transmitted. Each DAC may include an interpolator circuit that uses the received reference voltages to interpolate the reference voltages that were not transmitted. In this manner, the display driver may still provide the same number of unique reference voltages to a display screen while transmitting fewer reference voltages along the driver's optical channel.

Abstract: Embodiments described herein synchronize a switching frequency of switched power supplies with timing events associated with updating a display screen or performing touch sensing. For example, a touch event may be the time needed for a touch controller to scan a plurality of sensing electrodes. Because noise is introduced each time switched power supplies switch between different stages, the touch controller may instruct a power management controller to switch between the stages (i.e., adjust the switching frequency) at the same time during each touch event. Even though the switched power supplies are permitted to introduce noise into the touch system, the noise happens at the same time during each touch event. Accordingly, the effect of the noise is the same for each touch event and is cancelled out. A similar process may be used for synchronizing the switching frequency to display events.

Abstract: An input device processing system comprises a sensor module that transmits a first transmitter signal with a transmitter electrode and receives a resulting signal with a receiver electrode. The first transmitter signal comprises a first transmitter frequency, and the resulting signal comprises effects corresponding to the first transmitter signal. A demodulation module demodulates the resulting signal to produce a first signal (e.g., an upper sideband signal) and a second signal (a lower sideband signal), selectably determines a first measurement of a change in capacitive coupling between the transmitter electrode and the receiver electrode based on at least one of the first and second signals, and determines positional information for an input object based on the first measurement.

Abstract: Embodiments of the invention generally provide an input device that includes one or more source drivers that are coupled to a display screen. Specifically, one of the source drivers may be coupled to a plurality of source lines (or column lines) on the display screen which the source driver uses to set voltages associated with one or more sub-pixels that determine the color displayed by the pixel. When driving voltages onto subsequent source lines, the input device may precharge the source driver using a latent voltage stored on the source lines. That is, if the source line was previously driven to a particular voltage by the source driver, the input device uses that latent voltage to precharge the output of the source driver to the same voltage. The source driver may then adjust its output to a desired voltage and drive the desired voltage onto the source line and sub-pixel.

Abstract: An input device processing system comprises a sensor module that transmits a first transmitter signal with a transmitter electrode and receives a resulting signal with a receiver electrode. The first transmitter signal comprises a first transmitter frequency, and the resulting signal comprises effects corresponding to the first transmitter signal. A demodulation module demodulates the resulting signal to produce a first signal (e.g., an upper sideband signal) and a second signal (a lower sideband signal), selectably determines a first measurement of a change in capacitive coupling between the transmitter electrode and the receiver electrode based on at least one of the first and second signals, and determines positional information for an input object based on the first measurement.

Abstract: A display driver maps a selection code (a digital signal) to a reference voltage which is then used to produce a particular intensity of the radiation emitted from a pixel on a display screen (e.g., a LCD display). This mapping may be performed by one or more DACs in the display driver. However, instead of transmitting all of the different possible reference voltages to the DACs, only a subset of the reference voltages are transmitted. Each DAC may include an interpolator circuit that uses the received reference voltages to interpolate the reference voltages that were not transmitted. In this manner, the display driver may still provide the same number of unique reference voltages to a display screen while transmitting fewer reference voltages along the driver's optical channel.

Abstract: A voltage generator circuit comprises a resistor string, a drive mechanism configured to drive a drive signal, a voltage feedback network, and a voltage tap point. The voltage tap point is located along the resistor string. The voltage tap point is configured to be selectively coupled simultaneously with the drive mechanism and the voltage feedback network, such that an output of the voltage tap point is selectively coupled with the drive mechanism via the voltage feedback network.

Abstract: An apparatus is provided, which includes a driving circuit. The driving circuit includes a gamma reference source and a liquid crystal display (LCD) source driver circuit. A first resistor string is provided. A plurality of digital-to-analog converters (DACs) are provided, where each DAC is coupled to the first resistor string. An output circuit having a second resistor string is provided so as to output a plurality of reference voltages. The LCD source driver circuit is coupled to the output circuit of the gamma reference source. The source driver is configured to receive the plurality of reference voltages, wherein the plurality of reference voltages are arranged in a first sequence during a positive polarity cycle and are arranged in a second sequence during a negative polarity cycle. The fifth sequence is an inverse of the fourth sequence.