Synaptics Corporation

Jeremy Roberson

David A Sobel

Adam L Schwartz

Damien Berget

Eric Scott Bohannon

Farzaneh Shahrokhi

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.

System and method for synchronizing sensing signals of integrated circuit chips

Embodiments disclosed herein generally relate to electronic devices, and more specifically, to a waveform generation circuit for input devices. One or more embodiments provide a new waveform generator for an integrated touch and display driver (TDDI) and methods for generating a waveform for capacitive sensing with a finely tunable sensing frequency. A waveform generator includes accumulator circuitry, truncation circuitry, and saturation circuitry. The accumulator circuitry is configured to accumulate the phase increment value based on a clock signal, and output the accumulated phase increment value. The truncation circuitry configured to drop one or more bits of the accumulated phase increment value to output a truncated value. The saturation circuitry is configured to compare the truncated value to a saturation limit and output a signal corresponding to accessed data samples.

Waveform generation circuit for finely tunable sensing frequency

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.

Continuous time anti-alias filter for capacitive touch sensing

A processing system configured to sense an input object in a sensing region of a sensing device including a transmitter module coupled to a first transmitter electrode and a second transmitter electrode and configured to simultaneously apply a first transmitter signal to the first transmitter electrode and a second transmitter signal to the second transmitter electrode, wherein the first transmitter signal is based on a first one of a plurality of distinct codes and the second transmitter signal is based on a second one of the plurality of distinct codes. The processing system also includes a receiver module including receiver circuitry coupled to a first receiver electrode and configured to receive a first resulting signal with the first receiver electrode, the first resulting signal comprising effects corresponding to the first and second transmitter signals and a noise component. The processing system is configured to determine an estimate of the noise component using a third one of the plurality of distinct codes which is not associated with a transmitter signal.

Sensor device and method for estimating noise in a capacitive sensing device

A processing system for an input device includes a transmitter modules coupled to a plurality of transmitter electrodes including a first set and a second set of transmitter electrodes, the first set and second set being disjoint and having different sizes. The transmitter module is configured to simultaneously transmit a first plurality of transmitter signals with the first set of transmitter electrodes during a first period, and to simultaneously transmit a second plurality of transmitter signals with the second set of transmitter electrodes during a second period, wherein the first period and the second period are non-overlapping. Each of the first plurality of transmitter signals is based on a different sequence of a code, which includes a set of mathematically independent sequences and has a size equal to the size of the first set of transmitter electrodes.

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San Jose, CA, United States of America

Jeremy Roberson