Abstract: A system and method for synchronizing multiple integrated circuit (IC) chips for an input device having a display device integrated with a capacitive sensing device. A first one of the IC chips is a master IC chip and a second one of the IC chips is a slave IC chip. The master IC chip is configured to transmit synchronization signals to and from the slave IC chip, such that capacitive frames are acquired by each of the IC chips at substantially the same time, the initiation of the sensing signals is synchronized for each of the IC chips and the clock signals of the slave IC chips are synchronized with the clock signal of the master IC chip.

Abstract: An input device is configured to detect signals from of an input object. Examples include acquiring a first signal on a first sensor electrode of the input device; acquiring a second signal on a second sensor electrode of the input device; combining the first signal and the second signal to produce a combined signal; demodulating the combined signal to determine an in-phase component of the combined signal and a quadrature component of the combined signal; and combining the in-phase component and the quadrature component to determine signal magnitude information.

Abstract: Embodiments described herein include an input device with a plurality of capacitive sensor electrodes configured to receive a signal. The input device also includes a processing system coupled to the plurality of capacitive sensor electrodes. The processing system includes an analog front end (AFE). The AFE includes an anti-aliasing filter comprising a continuous time analog infinite impulse response (IIR) filter configured to filter out interference from the received signal at frequencies higher than a signal frequency of the processing system to produce an anti-aliased signal. The AFE also includes a charge integrator configured to integrate the anti-aliased signal.

Abstract: An input device including: a first in-phase touch sensing block including: an analog mixer configured to mix a resulting signal associated with a capacitive sensor electrode with a local oscillator (LO) signal; an analog to digital converter (ADC) configured to convert an output of the analog mixer into a digital signal; and a first decimation filter configured to determine an in-phase component of an interference at a frequency of the LO signal based, at least in part, on the digital signal; and a first quadrature interference detection block including: a second decimation filter configured to determine a quadrature component of the interference at the frequency.

Abstract: An input device including: a first in-phase touch sensing block including: an analog mixer configured to mix a resulting signal associated with a capacitive sensor electrode with a local oscillator (LO) signal; an analog to digital converter (ADC) configured to convert an output of the analog mixer into a digital signal; and a first decimation filter configured to determine an in-phase component of an interference at a frequency of the LO signal based, at least in part, on the digital signal; and a first quadrature interference detection block including: a second decimation filter configured to determine a quadrature component of the interference at the frequency.

Abstract: An example circuit includes: a filter configured to process a digital signal through at least one stage; and a coefficient generator circuit configured to generate coefficients for the at least one stage of the filter. The coefficient generator circuit includes: a lookup-table (LUT) configured to output a differential sequence; an up-sampling holder circuit configured to up-sample and hold the differential sequence to generate an up-sampled differential sequence; and an accumulator configured to integrate the up-sampled differential sequence to generate the coefficients.

Abstract: An example circuit includes: a filter configured to process a digital signal through at least one stage; and a coefficient generator circuit configured to generate coefficients for the at least one stage of the filter. The coefficient generator circuit includes: a lookup-table (LUT) configured to output a differential sequence; an up-sampling holder circuit configured to up-sample and hold the differential sequence to generate an up-sampled differential sequence; and an accumulator configured to integrate the up-sampled differential sequence to generate the coefficients.

Abstract: A processing system for an input device, the processing system including: a sensor module coupled to sensor circuitry and configured to: initiate a current beacon period including a plurality of timeslots by broadcasting a current beacon signal to a plurality of active pens; receive, during a first timeslot, a first downstream packet from a first active pen transceiver; and receive, during a second timeslot, a second downstream packet from a second active pen transceiver; and a determination module configured to: determine an attribute of a first active pen including the first active pen transceiver from at least the first downstream packet.

Abstract: An input device is configured to detect signals from of an input object. Examples include acquiring a first signal on a first sensor electrode of the input device; acquiring a second signal on a second sensor electrode of the input device; combining the first signal and the second signal to produce a combined signal; demodulating the combined signal to determine an in-phase component of the combined signal and a quadrature component of the combined signal; and combining the in-phase component and the quadrature component to determine signal magnitude information.

Abstract: An example circuit includes: a plurality of analog-to-digital converters (ADCs) receiving a respective plurality of analog signals and outputting a respective plurality of digital signals; a coefficient generator circuit outputting a coefficient signal; and a plurality of decimation filters each including a first input that receives a respective one of the plurality of digital signals and a second input that receives the coefficient signal, each of the plurality of decimation filters including a finite impulse response (FIR) filter having a multiplier and a single accumulator.

Abstract: A method of capacitive sensing may include driving a first modulated signal onto a first sensor electrode in an input device and a second modulated signal onto a second sensor electrode in the input device. The method may further include receiving, simultaneously, a first resulting signal from the first sensor electrode and a second resulting signal from the second sensor electrode. The method may further include generating, based at least in part on the first resulting signal and the second resulting signal, a combination signal. The method may further include determining, using the combination signal, when the input device is not disposed in a predetermined low ground mass state, and when a ratio of capacitive coupling exceeds a predetermined threshold, first positional information regarding a location of the input object in the sensing region.

Abstract: Embodiments described herein include a method, input device, and processing system for capacitive sensing. The input device comprises a plurality of transmitter electrodes and a plurality of receiver electrodes. The method comprises transmitting, on one or more of the plurality of transmitter electrodes, a capacitive sensing signal comprising a plurality of sensing half-cycles. The method further comprises sampling, two or more times during each sensing half-cycle, effects of the transmitted capacitive sensing signal on one or more of the plurality of receiver electrodes to produce half-cycle sensing data, filtering the half-cycle sensing data, and determining positional information for an input object using the filtered half-cycle sensing data.

Abstract: Embodiments described herein include an input device with a plurality of capacitive sensor electrodes configured to receive a signal. The input device also includes a processing system coupled to the plurality of capacitive sensor electrodes. The processing system includes an analog front end (AFE). The AFE includes an anti-aliasing filter comprising a continuous time analog infinite impulse response (IIR) filter configured to filter out interference from the received signal at frequencies higher than a signal frequency of the processing system to produce an anti-aliased signal. The AFE also includes a charge integrator configured to integrate the anti-aliased signal.

Abstract: A processing system for an input device, the processing system including: a sensor module coupled to sensor circuitry and configured to: initiate a current beacon period including a plurality of timeslots by broadcasting a current beacon signal to a plurality of active pens; receive, during a first timeslot, a first downstream packet from a first active pen transceiver; and receive, during a second timeslot, a second downstream packet from a second active pen transceiver; and a determination module configured to: determine an attribute of a first active pen including the first active pen transceiver from at least the first downstream packet.

Abstract: Provided are systems and methods for providing enhanced touch sensing. One system providing enhanced touch sensing includes a multi-mode touch screen and a processor configured to apply at least one test signal to a sense element of the multi-mode touch screen, detect at least one return signal from the sense element, and then determine a relative position of an object corresponding to the at least one return signal, the multi-mode touch screen being capable of sensing the first object using first and second detection modes. One multi-mode touch screen comprises a multi-mode multi-touch touch screen. One processor is configured to apply an adaptive test signal to a sense element of a touch screen.

Abstract: Asymmetric scanning logic implements asymmetric panel scanning by scanning some rows on a touch panel more frequently than other rows. Note that although an entire row at a time may be driven, if only particular pixels in the row are of interest (e.g., included in any region of interest for focused asymmetric scanning), then circuitry may power down the receivers for the columns in which the pixels exist to save power. The asymmetric scanning logic facilitates focused attention to specific areas of interest on the touch panel, to compensate, for example, for high noise or low signal strength in those areas of interest.

Abstract: Systems and methods are provided that allow a touch sensor, such as a mutual capacitive touch panel, to switch from an operative transmit (TX) frequency at which the mutual capacitive touch panel is driven to an alternative TX frequency. When switching to an alternative TX frequency, an alternative baseline capacitance value corresponding to the alternative TX frequency may be utilized to determine whether a touch event has occurred on the mutual capacitive touch panel. Frame scans can be repeatedly performed at the operative TX frequency and the alternative TX frequency in rapid succession, and an average difference of the frame scans can be calculated and utilized to generate the alternative baseline capacitance value which may be insensitive to sudden ambient changes and moving touch events affecting the mutual touch capacitive panel.

Abstract: Provided are systems and methods for providing enhanced touch sensing. One system providing enhanced touch sensing includes a multi-mode touch screen and a processor configured to apply at least one test signal to a sense element of the multi-mode touch screen, detect at least one return signal from the sense element, and then determine a relative position of an object corresponding to the at least one return signal, the multi-mode touch screen being capable of sensing the first object using first and second detection modes. One multi-mode touch screen comprises a multi-mode multi-touch touch screen. One processor is configured to apply an adaptive test signal to a sense element of a touch screen.

Abstract: Systems and methods are provided that allow a touch sensor, such as a mutual capacitive touch panel, to switch from an operative transmit (TX) frequency at which the mutual capacitive touch panel is driven to an alternative TX frequency. When switching to an alternative TX frequency, an alternative baseline capacitance value corresponding to the alternative TX frequency may be utilized to determine whether a touch event has occurred on the mutual capacitive touch panel. Frame scans can be repeatedly performed at the operative TX frequency and the alternative TX frequency in rapid succession, and an average difference of the frame scans can be calculated and utilized to generate the alternative baseline capacitance value which may be insensitive to sudden ambient changes and moving touch events affecting the mutual touch capacitive panel.

Abstract: A touch sensitive pad with a plurality of touch sensitive elements and processing circuitry coupled to a communications interface and to the touch sensitive pad for scanning the plurality of touch sensitive elements to measure a plurality of touch sensitive element values. The plurality of touch sensitive element values is compared to a hovering finger threshold pattern. Upon a favorable comparison, a hovering finger condition is determined, and a position of the hovering finger in three-dimensions is detected with respect to the touch sensitive pad. The plurality of touch sensitive element values is compared to a touching finger threshold pattern. Upon a favorable comparison, a touching finger condition is determined, and a position of the touching finger is detected upon the touch sensitive pad.