CALIBRATION METHOD, CORRESPONDING CIRCUIT AND APPARATUS

    公开(公告)号:US20220021373A1

    公开(公告)日:2022-01-20

    申请号:US17371368

    申请日:2021-07-09

    Abstract: In accordance with an embodiment, a method of operating a piezoelectric transducer configured to transduce mechanical vibrations into transduced electrical signals at a pair of sensor electrodes includes stimulating a resonant oscillation of the piezoelectric transducer by applying at least one pulse electrical stimulation signal to the pair of sensor electrodes; detecting, at the pair of sensor electrodes, at least one electrical signal resulting from the stimulated resonant oscillation, wherein the at least one electrical signal resulting from the stimulated resonant oscillation oscillates at a resonance frequency of the piezoelectric transducer; measuring a frequency of oscillation of the at least one electrical signal resulting from the stimulated resonant oscillation to obtain a measured resonance frequency of the piezoelectric transducer; and tuning a stopband frequency of a notch filter coupled to the piezoelectric transducer to match the measured resonance frequency of the piezoelectric transducer.

    LDO FREE WIRELESS POWER RECEIVER HAVING RECTIFIER

    公开(公告)号:US20220021241A1

    公开(公告)日:2022-01-20

    申请号:US16930651

    申请日:2020-07-16

    Inventor: Yannick GUEDON

    Abstract: Disclosed herein is a bridge rectifier and associated control circuitry collectively forming a “regtifier”, capable of both rectifying an input time varying voltage as well as regulating the rectified output voltage produced. To accomplish this, the gate voltages of transistors of the bridge rectifier that are on during a given phase may be modulated via analog control (to increase the on-resistance of those transistors) or via pulse width modulation (to turn off those transistors prior to the end of the phase). Alternatively or additionally, the transistors of the bridge rectifier that would otherwise be off during a given phase may be turned on to help dissipate excess power and thereby regulate the output voltage. A traditional voltage regulator, such as a low-dropout amplifier, is not used in this design.

    Adaptive baseline correction for delta amplification

    公开(公告)号:US11165286B1

    公开(公告)日:2021-11-02

    申请号:US16899990

    申请日:2020-06-12

    Abstract: A data demodulating circuit includes a sensing circuit sensing a power signal applied to a coil at first and second times, and outputting an analog value representing a difference in voltage of the power signal at the first and second times. An analog-to-digital converter digitizes the analog value output by the analog voltage differential sensing circuit to produce a digital code. A compensation circuit, over a period of time, compares a present value of the digital code to a first value of the digital code during the period, and subtracts a given value from the present value of the digital code if the present value is greater than the first value but add the given value to the present value of the digital code if the present value is less than the first value. An accumulator accumulates output of the compensation circuit, and a filter filters output of the accumulator.

    Foreign objection detection sensing circuit for wireless power transmission systems

    公开(公告)号:US11152822B1

    公开(公告)日:2021-10-19

    申请号:US17037982

    申请日:2020-09-30

    Abstract: 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.

    Hardware and method for enhanced wireless receiver output power

    公开(公告)号:US11128170B1

    公开(公告)日:2021-09-21

    申请号:US16897429

    申请日:2020-06-10

    Inventor: Yannick Guedon

    Abstract: A power transmission system includes at least one wireless power transmission circuit. A first wireless power reception circuit includes a first circuit comparing a reference voltage to a feedback voltage representing an output voltage produced from received power and delivered to an output node, and adjusting a first control terminal of a device supplying a first rectified voltage until the feedback and reference voltages are equal. A second wireless power reception circuit includes a second circuit modifying a control terminal of a device sourcing a second rectified current produced from received power to the output node, based upon comparison of a reference current to a current representative of the second rectified current. Control circuitry adjusts the reference current until a first rectified voltage generated by the first wireless power reception circuit and a second rectified voltage generated by the second wireless power reception circuit are equal.

    Partial mutual capacitive touch sensing in a touch sensitive device

    公开(公告)号:US10996792B2

    公开(公告)日:2021-05-04

    申请号:US16130332

    申请日:2018-09-13

    Abstract: Disclosed herein is a method of operating a touch screen controller in a device with a touch screen having force lines and sense lines. The method includes receiving touch data from the touch screen, and operating the touch screen in a self capacitance sensing mode. In the self capacitance sensing mode, which force lines have strength values indicating a potential touch to the touch screen are determined. The method also includes operating the touch screen in a mutual capacitance sensing mode, and in the mutual capacitance sensing mode, performing mutual capacitance sensing on only a subset of the force lines, with the subset of the force lines including at least those force lines indicating the potential touch to the touch screen.

    Energy recovery from a spindle motor using a sequence of a braking phase, an active step-up phase and an active braking phase in response to external power supply failure

    公开(公告)号:US10944341B2

    公开(公告)日:2021-03-09

    申请号:US16410674

    申请日:2019-05-13

    Abstract: The half-bridges driving a multiphase motor are controlled to perform a sequence of operations to support charging a hold capacitor. First, in a brake configuration, the half-bridge transistors are controlled such that either high-side transistors or low-side transistors of the half-bridges are turned on. Second, in an active step-up configuration, the half-bridge transistors are controlled such that the high-side transistor of a first half-bridge and the low-side transistor of a second half-bridge are both turned on and the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned off. Third, in an active brake configuration, the half-bridge transistors are controlled such that the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned on and the high-side transistor of the first half-bridge and the low-side transistor of the second half-bridge stage are both turned off.

    Auto zero offset current mitigation at an integrator input

    公开(公告)号:US10790791B2

    公开(公告)日:2020-09-29

    申请号:US16184778

    申请日:2018-11-08

    Abstract: A feedback stage for an integrator circuit is provided. The integrator receives a first input current and a second input current that include respective measurement current components and an offset current component. The integrator integrates the first input current and the second input current and generates a first output voltage and a second output voltage. The feedback stage including a transconductance amplifier detects a difference between the first output voltage and the second output voltage and sinks or sources a first output current and a second output current based on the difference between the first output voltage and the second output voltage. The first output current is additively combined with the first input current and the second output current is additively combined with the second input current to mitigate the offset current component at an input of the integrator.

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