Stmicroelectronics Asia Pacific Pte Limited

Marvell International Limited

Stmicroelectronics S.r.l.

Stmicroelectronics International N.v.

Tritech Microelectronics, Ltd

Kien Beng Tan

Dianbo Guo

Chee Weng Cheong

Yannick Guedon

Leonard Liviu Dinu

Baranidharan Karuppusamy

Ernesto Lasalandra

Paolo Angelini

Tommaso Ungaretti

Xiao Yu Miao

Giovanni Carlo Tripoli

Eng Jye Ng

Praveesh Chandran

Giuseppe Noviello

Chaochao Zhang

Jenn Woei Soo

Sze-Kwang Tan

Teerasak Lee

Supriya Raveendra Hegde

Cam Chung La

Huiqiao He

Tong Tee Tan

CheeWeng Cheong

Thet Mon Sann

Kusuma Adi Ningrat

Parviz Rahgozar

Sang Kong Chan

Min Sang Kim

Gee H Loh

Hon Siong Ng

Hong Chean Choo

Tze Yong Poh

Boon Loong Woo

Leonard Dinu

Chan Sang Kong

A wireless power receiver includes a rectifier with first and second inputs coupled to first and second terminals of a receiver coil, and having a first output coupled to ground and a second output at which a rectified voltage is produced. A first switch is coupled between the second input and ground, and is controlled by a first gate voltage generated at a first node. A second switch is coupled between the first node and ground, and is controlled by a second gate voltage. The first gate voltage closes the first switch to couple the second input to ground when the rectified voltage is less than a threshold voltage, boosting the rectified voltage. The second gate voltage closes the second switch to cause the second gate voltage to be pulled to ground when the rectified voltage is greater than the threshold voltage, limiting the boosting of the rectified voltage.

Adaptive boosting of rectified voltage in a wireless charging system

A method for operating a touch sensing panel includes a touchscreen controller determining a first plurality of excitation signals in accordance with a first plurality of codes, wherein a sum of the first plurality of codes is a sequence of numbers having a same absolute value and signs alternating between adjacent numbers in the sequence of numbers. The method further includes the touchscreen controller transmitting each of the first plurality of excitation signals to a respective transmitting (TX) touch sensor of the touch sensing panel simultaneously during a first time frame. The method further includes the touchscreen controller determining touch strengths in accordance with a first plurality of output signals received by a plurality of receiving (RX) touch sensors of the touch sensing panel during the first time frame.

Capacitive scan method without display flicker

A method for operating a display includes receiving a horizontal synchronization (HSYNC) signal from a display driver of the display, the HSYNC signal including a plurality of pulses; measuring a parameter of the HSYNC signal within a frame; and initiating a touch scan on a touch sensing panel of the display based on the measured parameter.

Methods and systems for adaptive touchscreen control

A wireless power circuit operable in transceiver mode and in Q-factor measurement mode includes a bridge rectifier having first and second inputs coupled to first and second terminals of a coil, and an output coupled to a rectified node. An excitation circuit coupled to the first terminal, in Q-factor measurement mode, drives the coil with a pulsed signal. A protection circuit couples the first terminal to a first node when in Q-factor measurement mode and decouples the first terminal when in transceiver mode. A controller causes the bridge rectifier to short the first and second terminals to ground during Q-factor measurement mode. A sensing circuit amplifies voltage at the first node to produce an output voltage, and in response to the voltage at the first node rising to cross a rising threshold voltage, digitizes the output voltage. The digitized output voltage is used in calculating a Q-factor of the coil.

Foreign objection detection sensing circuit for wireless power transmission systems

In an example, a method of sensing on a touchscreen including a plurality of touch sensors arranged in rows and columns on the touchscreen is described. The method includes detecting a passive touch on the touchscreen and a positon of an active stylus; determining a plurality of locations across the touchscreen corresponding to the passive touch and a positon of the active stylus, where each of the plurality of locations corresponds to a location of one of the plurality of touch sensors. The method includes transmitting a first uplink signal to a first group of the plurality of locations including a first fraction of the plurality of locations; and transmitting a second uplink signal to a second group of the plurality of locations including a second fraction of the plurality of locations, the first uplink signal being different from the second uplink signal.

Stylus sensing on touchscreens

A wireless-power-circuit is operable in transceiver-mode and Q-factor-measurement-mode, and includes a bridge coupled to a coil, and having an output coupled to a rectified-voltage node. An excitation circuit, when in Q-factor-measurement-mode, drives the coil with a pulsed signal. A protection circuit couples the coil to a first node when in Q-factor-measurement-mode and decouples the coil from the first node when in transceiver-mode. A Q-factor sensing circuit includes an amplifier having inputs coupled to the first node and a common mode voltage (Vcm), and generating an output signal having an output voltage. A comparator generates a comparison output indicating Vcm crossing of a voltage at the first terminal of the coil, a processing circuit generating an enable signal based upon the comparison output, and an analog-to-digital-converter, when enabled, digitizing the output voltage for use in calculating a Q-factor of the coil.

A determination is made as to whether touch pressure data acquired from each of a plurality of touch pressure sensors is indicative of abnormal operation. If abnormal operation is indicated, the touch pressure data from each of the plurality of touch pressure sensors, except those touch pressure sensors having touch pressure data indicative of abnormal operation, is summed. Then, the sum is multiplied by a correction factor to produce a touch pressure output indicative of physical force applied to the plurality of touch pressure sensors.

Methods and techniques for correcting pressure sensor data in the presence of abnormal pressure sensor readings

A device includes a touch and pressure sensitive screen having touch pressure sensors and a controller. The controller acquires touch pressure data from the plurality of touch pressure sensors. For each touch pressure sensor, the controller determines whether the touch pressure data from that touch pressure sensor is indicative of abnormal operation of that touch pressure sensor. Where no abnormal operation is indicated, the controller sums the touch pressure data from each of the touch pressure sensors to produce a touch pressure output. Where abnormal operation is indicated, the controller sums the touch pressure data from each of the touch pressure sensors and multiply the sum by a correction factor to produce the touch pressure output.

A capacitive discharge circuit includes a line having a capacitance, a switched capacitor circuit including a capacitor, a switched circuit coupled to the line, and a voltage regulator coupled between the switched capacitor circuit and the switched circuit. A controller operates the switched capacitor circuit and switched circuit to in a first phase, charge the capacitor by coupling the capacitor between a common mode and a power supply, and in a second phase, discharge the capacitor by coupling the voltage regulator in series with the capacitor between the power supply node a ground. The controller is also configured to in a third phase, charge the capacitor by coupling the capacitor between the common mode and the power supply, and in a fourth phase, share charge between the line and the capacitor by coupling the voltage regulator and the capacitor in series between the line and the ground.

Capacitive discharge circuit for touch sensitive screen

A system and method for synchronizing two devices in communication with each other. When communication between the two devices is to be established, a synchronization process may be invoked. In an embodiment, a first device may initiate sending synchronization signals having rising edge and falling edge pairs. The second device may include a controller configured to receive the synchronization signals. However, noise may inhibit the ability of the controller to correctly receive and/or interpret the synchronization signals. Noise may cause detection components to falsely detect noise as a synchronization signal or may cause detection components to miss detection of an actual synchronization signal. A window generator may be used to generate comparison windows for the controller to detect synchronization signals. Further, the detection window duration and start times may be adjusted based on previously detected (or undetected) synchronization signals in order to compensate for noise overshadowing synchronization signals.

System and method for improved synchronization between devices

An active stylus is capacitively coupled to a capacitive touch panel for communication. The active stylus operates in a wait mode to receive initial communications from the panel. In response to such receipt, the active stylus synchronizes to a repeating communications frame implementing time division multiplexing. Communications from the active stylus to the panel include: information communications; synchronization communications and communications specific for columns and/or rows of the panel. Communications from the panel to the active stylus may be addressed uniquely to the stylus or commonly to a group of styluses.

System and method of communication between a capacitive touch screen and an active stylus

Disclosed herein is an electronic device including a first touch circuit to be coupled to a first touch sensing unit, the first touch sensing unit having first drive lines and first sense lines intersecting the first drive lines. A second touch circuit is to be coupled to a second touch sensing unit, the second touch sensing unit having second drive lines and second sense lines intersecting the second drive lines. A touch force circuit is to be coupled to a touch force sensing unit, the touch force sensing unit having third drive lines and third sense lines intersecting the third drive lines. The first touch circuit, second touch circuit, and touch force circuit are configured to drive the first, second, and third drive lines as a function of a synchronization signal, and acquire data from the first, second, and third sense lines as a function of the synchronization signal.

Correlated data acquisition among different touch sensors

Growing community of inventors

Singapore, Singapore

Kien Beng Tan