Abstract: A class D amplifier is provided, including: a first comparator, configured to generate a first comparison result based on a positive end input signal and a triangular wave; a second comparator, configured to generate a second comparison result based on a negative end input signal and the triangular wave; an exclusive OR gate, configured to generate a first control signal based on the first comparison result and the second comparison result; a first AND gate, configured to generate a positive end PMW output based on the first comparison result and the first control signal; and a second AND gate, configured to generate a negative end PMW output based on the second comparison result and the first control signal; and an output stage, configured to generate the positive end output signal and the negative end output signal correspondingly based on the positive end PMW output and the negative end PMW output.

Abstract: A voltage attack detection circuit of a chip includes: a first programmable resistor and a second programmable resistor, a first terminal of the first programmable resistor is connected to a supply voltage, a second terminal of the first programmable resistor is connected to a ground voltage through the second programmable resistor, the first terminal outputs a first voltage, the second terminal outputs a second voltage; a voltage detection circuit, receives the first voltage and a first reference voltage and output a first signal, where the first signal is configured to indicate whether the first voltage is greater than or equal to the first reference voltage, the voltage detection circuit is further configured to receive the second voltage and a second reference voltage and output a second signal, and the second signal is configured to indicate whether the second voltage is less than or equal to the second reference voltage.

Abstract: An operational amplifier-based hysteresis comparator and a chip are provided. The hysteresis comparator includes: an input stage and an amplification stage. The input stage includes: a first input branch and a second input branch, where the first input branch generates a first current based on the first voltage, and the second input branch generates a second current based on the second voltage. The first current is connected with a first input terminal of the amplification stage, and the second current is connected with a second input terminal of the amplification stage. An output terminal of the amplification stage outputs a first level when the first current is greater than the second current, and outputs a second level when the first current is less than the second current. The present disclosure changes the hysteresis voltage generation mode, thereby reducing the instability caused by positive feedback.

Abstract: An ultrasonic fingerprint apparatus and an electronic device are provided. The ultrasonic fingerprint apparatus is disposed under a display of an electronic device to implement under-display ultrasonic fingerprint recognition. The ultrasonic fingerprint apparatus includes an ultrasonic fingerprint chip and a piezoelectric transducer disposed on the ultrasonic fingerprint chip. The piezoelectric transducer includes a piezoelectric layer, an upper electrode on the piezoelectric layer, and a lower electrode under the piezoelectric layer. The ultrasonic fingerprint chip is a CMOS chip. The upper electrode is led out to a surface of the CMOS chip, and is connected to one end of a lead via a pad on the surface of the COMS chip, and the other end of the lead is connected to a circuit board under the ultrasonic fingerprint chip, to implement an electrical connection between the piezoelectric transducer and the circuit board.

Abstract: A touch control chip, a coding method, and an electronic device are provided, which can effectively reduce influence of a coding signal of a touch control layer of a screen on a display layer. The touch control chip includes: a driving circuit configured to output the coding signal to a display layer of the screen; and a control circuit configured to adjust a driving impedance of the driving circuit during a period when the driving circuit outputs the coding signal, so that a value of the driving impedance in a display sensitive interval of the display layer is greater than a value of the driving impedance in a time interval outside the display sensitive interval, where the display sensitive interval includes a pixel update interval of the display layer, and the pixel update interval is the time interval for a pixel in the display layer to receive a data signal.

Abstract: Embodiments of the present application provide a fingerprint identification method, a fingerprint identification apparatus and an electronic device. The fingerprint identification method is applied to a fingerprint identification apparatus disposed under a display screen of an electronic device, the fingerprint identification apparatus includes a pixel array and a colour filter layer, the colour filter layer includes at least one filter unit, and the at least one filter unit is disposed above at least one first type pixel of the pixel array, respectively, and the method includes: capturing a first light signal transmitting through the at least one filter unit and sensed by the first type pixel; determining a fingerprint identification environment according to an intensity of the first light signal; and determining, based on the fingerprint identification environment, a target capturing parameter of capturing a fingerprint light signal, the fingerprint light signal being used for fingerprint identification.

Abstract: The present disclosure provides a method for wireless communication, which is applicable to wireless communication between the active pen and the plurality of touch screens, the plurality of touch screens respectively correspond to a plurality of wireless channels, a respective wireless channel is used for wireless communication between a touch screen and the active pen, and the method includes: the active pen sends a coding signal to the first touch screen; the active pen receives a wireless signal sent by the first touch screen, the wireless signal carries identification information of the first touch screen; the active pen identifies the first touch screen that is currently close to or in contact with the active pen according to the identification information of the first touch screen; and the active pen sends a wireless message to the first touch screen through the wireless channel corresponding to the first touch screen.

Abstract: Provided are an apparatus for acquiring a depth image, a method for fusing depth images, and a terminal device. The apparatus for acquiring a depth image includes an emitting module, a receiving module, and a processing unit. The emitting module is configured to emit a speckle array to an object, where the speckle array includes p mutually spaced apart speckles. The receiving module includes an image sensor. The processing unit is configured to receive the pixel signal and generate a sparse depth image based on the pixel signal, align an RGB image at a resolution of a*b with the sparse depth image, and fuse the aligned sparse depth image with the RGB image using a pre-trained image fusion model to obtain a dense depth image at a resolution of a*b.

Abstract: Embodiments of the present disclosure provide a method for capturing a fingerprint image, an apparatus for capturing a fingerprint image, and an electronic device, where the method includes: controlling a fingerprint sensor to capture at least one frame of image based on each candidate exposure time among N candidate exposure times respectively; determining N values of a feature parameter corresponding to the N candidate exposure times according to the at least one frame of image captured in each exposure time, where the feature parameter is used to indicate a degree of influence of a refresh period of a display screen on the fingerprint image captured by the fingerprint sensor; determining a candidate exposure time corresponding to a first value indicating a smallest degree of influence among the N values as a target exposure time; and controlling the fingerprint sensor to capture the fingerprint image based on the target exposure time.

Abstract: A clock calibration method and an electronic device, for calibrating a clock of a fingerprint chip, which can improve an accuracy of the clock of the fingerprint chip, thereby improving performance of the fingerprint chip. The clock calibration method, for calibrating a clock of a fingerprint chip provided in an electronic device, includes: sending a configuration command to the fingerprint chip to cause the fingerprint chip to map a current clock of the fingerprint chip to a target pin of the fingerprint chip; detecting the target pin to acquire the current clock of the fingerprint chip; determining a calibration value based on a target clock and the current clock of the fingerprint chip; and sending the calibration value to a calibration register in the fingerprint chip, the calibration value being used to adjust the current clock of the fingerprint chip.

Abstract: Embodiments of the present application provide a method and system for active noise control, which can meet different needs of different consumers on sound quality of headphones. The method includes: determining an expected noise control curve of performing active noise control on a target object; determining a target filter according to the expected noise control curve and a filter model; and performing noise control processing on an external noise signal using the target filter.

Abstract: A fingerprint identification apparatus and an electrode device. The fingerprint identification apparatus could be configured to be disposed under a variety of different display screens, reducing a thickness of space for installation of the fingerprint identification apparatus under a screen. The fingerprint identification apparatus includes: a support plate; and at least one fingerprint sensor chip, the at least one fingerprint sensor chip being disposed at an upper surface of the support plate; where the support plate is configured to be mounted to an upper surface of a middle frame of the electronic device so that the at least one fingerprint sensor chip is located under the display screen of the electronic device; and the at least one fingerprint sensor chip is configured to receive a fingerprint detecting signal returned by reflection or scattering via a human finger on the display screen.

Abstract: Techniques are described for discrete-time self-capacitor sensing in a touch panel. The self-capacitor manifests a detectably different capacitance based on presence or absence of a local touch event on the touch panel. In a first time phase, embodiments charge a self-capacitor and initialize a ramp bias generator. In a second time phase, embodiments discharge the self-capacitor with a ramp-controlled current source that is biased by the ramp bias generator to produce a discharge current that transitions from high at the beginning of the second time phase to low at the end of the second time phase. By the end of the second phase, the remaining charge in the self-capacitor depends on presence or absence of a local touch event. Some embodiments convert the remaining charge to an amplified sense output for readout.

Abstract: A method for managing a virtual electronic card is applicable to a secure chip installed in a first terminal, and the method includes: receiving a management request from a trusted mobile application on the first terminal, the management request being used to manage a target virtual electronic card on the secure chip, and permissions of the virtual electronic card being configured by a chip operating system of the secure chip; determining, from the secure chip, a target card management program corresponding to the target virtual electronic card, the different virtual electronic cards corresponding to the different card management programs; sending the management request to the target card management program; and calling, through the target card management program, a card management command corresponding to the management request in a card management system on the secure chip, to manage the target virtual electronic card.

Abstract: A method for determining a capacitance reference, an apparatus for determining a capacitance reference, and a device are provided. The method is applied to a device with double-layer capacitive sensors, and the method comprises: obtaining a first differential capacitance value of the double-layer capacitive sensors, the first differential capacitance value being a minimum differential capacitance value obtained when the device is out of a box, and the box being a matching device paired with the device and used to receive the device; and determining a latest differential capacitance reference value according to the first differential capacitance value and a differential capacitance reference value. By tracking and updating the differential capacitance reference value, a more accurate capacitance reference is provided to ensure the accuracy of capacitance change detection, and then to ensure the accuracy of detection on the behavior state of the device.

Abstract: A wearing detection apparatus and method, and an earphone are provided. The wearing detection apparatus is configured to be mounted on an earphone and includes: at least one first capacitive sensor and at least one second capacitive sensor, where the first capacitive sensor is disposed at an inner side of the second capacitive sensor; and a detection module configured to detect a first coupling capacitance between a touch object touching the earphone and the first capacitive sensor and a second coupling capacitance between the touch object and the second capacitive sensor when the earphone is touched, and to determine whether the earphone is worn by a human ear according to a difference between the first coupling capacitance and the second coupling capacitance.

Abstract: A method for improving NarrowBand Internet-of-Things radio network utilization by more efficiently and flexibly allocating available frequency spectrum resources to an UE. The objective to provide a method which allows efficient NB-IoT multi-carrier operation across different radio frequency bands or NB-IoT/LTE mother cells will be solved by a method for improving NarrowBand Internet of Things (NB-IoT) radio network utilization by more efficiently and flexibly allocating available frequency spectrum resources to an UE, where system information messages and/or dedicated signaling exchanged between an eNodeB and the UE are extended by specific parameters, setups and requests, so that multi-carrier operations are performable across all radio frequency bands even if the UE is already connected to the eNodeB.

Abstract: A capacitor includes: a semiconductor substrate; at least one trench provided in the semiconductor substrate and formed downward from an upper surface of the semiconductor substrate; a first conductive layer provided above the semiconductor substrate and in the trench; a first insulating layer provided between the substrate and the first conductive layer to isolate the first conductive layer from the substrate; a second conductive layer provided above the r substrate and in the trench, the second conductive layer including a first and a second conductive region that are independent from each other, the first conductive region being electrically connected to the substrate, and the second conductive region being electrically connected to the first conductive layer; and a second insulating layer provided between the first and the second conductive layer to isolate the first conductive region from the first conductive layer and isolate the second conductive region from the substrate.

Abstract: An ultrasonic fingerprint detection device and an electronic device are provided, which can reduce the size, circuit complexity and cost of the ultrasonic fingerprint detection device. The ultrasonic fingerprint detection device includes: a signal generation circuit and an ultrasonic fingerprint sensor chip, where the signal generation circuit is composed of discrete devices and the signal generation circuit includes: a control circuit and a resonant circuit, the control circuit is configured to receive a control signal provided by the ultrasonic fingerprint sensor chip and generate an excitation signal under the action of the control signal, and the resonant circuit is configured to receive the excitation signal and form a drive signal under the action of the excitation signal; and the ultrasonic fingerprint sensor chip is configured to receive the drive signal, and generate an ultrasonic signal for fingerprint detection under the action of the drive signal.

Abstract: Techniques are described for using an alternating-current-mode (AC-mode) bridge for low-noise self-capacitor sensing in a capacitive touch panel array integrated with a display panel. Each channel of the array has a self-capacitance (Ci) that changes responsive to presence or absence of a local touch event local. Pairs of channels are read out differentially by coupling pairs of channels to branches of an AC-mode bridge. The AC-mode bridge includes current sources that drive each branch (and thereby each channel) with a sinusoidal current, manifesting a branch voltage on each branch based on the self-capacitance of the branch. The branch voltages are used to generate an output voltage. The sinusoidal current is controlled by comparing a driver signal with feedback from the branches, so that common-mode noise on the channels becomes a common-mode component of the sinusoidal currents and is rejected in the generation of the output voltage.