Qualcomm Incorporated

Vijayakumar Dhanasekaran

Khaled Mahmoud Abdelfattah Aly

Kshitij Yadav

Dongyang Tang

Chien-Chung Yang

Ramkumar Sivakumar

Ankit Srivastava

Arash Mehrabi

Meysam Azin

Xinwang Zhang

Le Wang

Zongyu Dong

Yan Wang

Peter J Shah

Hui-Ya Liao Nelson

Jingxue Lu

Pradeep Charles Silva

Qubo Zhou

Xin Fan

Bengt Stefan Gustavsson

Wenchang Huang

Hanil Lee

ChienChung Yang

Arash Mashayekhi

A wireless device may include a plug that is shared by high speed data, analog audio signals, and power. Switches may be included on wires between the plug and the circuits that provide the high-speed data, analog audio signals and power to isolate those circuits from overvoltage conditions. Linearizer circuits may be included to provide gate driving signals to the switches, e.g., during transmission of analog audio signals. The linearizer circuits may include digital-to-analog converters to apply a gain factor to analog audio signals.

Linearizer circuits and methods for audio switches

A transmission line includes an equalization circuit. The equalization circuit is a second-order equalization circuit having a first loop at a gain element and a second loop at the gain element. The first loop may include a first compensation capacitor, and the second loop may include a second compensation capacitor and a resistor. The second order equalization circuit may allow for improved performance with respect to gain as well as reduced power usage.

Second-order equalizer for high-speed data lines

An aspect relates to an apparatus including a first pair of switching devices configured to selectively couple an application processor to a Universal Serial Bus (USB) differential data transmission lines; a USB host port connector coupled to the USB differential data transmission lines; a second pair of switching devices configured to selectively couple an audio circuit to the USB differential data transmission lines; and an equalizer including differential terminals coupled to the USB differential data transmission lines, respectively.

Universal serial bus (USB) host data switch with integrated equalizer

A differential ESD circuit is provided for protecting a pair of differential terminals of an integrated circuit from electrostatic shock. A first diode couples between a first terminal in the pair of differential terminals and a first resistor that couples to a voltage node of the integrated circuit. Similarly, a second diode couples between a second terminal in the pair of differential terminals and a second resistor that couples to the voltage node of the integrated circuit. The first and second resistors isolate the first and second terminals from a capacitive loading that would otherwise exist from the first and second diodes.

Fully differential ESD circuit for high-frequency applications

An aspect of the disclosure relates to an apparatus, including an audio interface including first and second outputs; a crosstalk cancelling circuit including first and second inputs coupled to the first and second outputs of the audio interface, respectively; a first summer including a first input coupled to the first output of the audio interface and a second input coupled to a first output of the crosstalk cancelling circuit; a second summer including a first input coupled to the second output of the audio interface and a second input coupled to a second output of the crosstalk cancelling circuit; a first digital to analog converter (DAC) including an input coupled to an output of the first summer; and a second DAC including an input coupled to an output of the second summer.

Audio ground switch channel crosstalk cancellation technique

An aspect includes an apparatus including a first amplifier; a first field effect transistor (FET) including a first source coupled to an output of the first amplifier, and a first drain for coupling to a first load; and a first gate drive circuit including an input coupled to the output of the first amplifier and an output coupled to a first gate of the first FET. Another aspect includes a method including amplifying a first audio signal using a first audio amplifier to generate a first voltage; generating a first gate voltage based on the first voltage; applying the first gate voltage to a first gate of a first field effect transistor (FET) coupled between the first audio amplifier and a first audio transducer; and applying the first voltage to a first source of the first FET.

Audio non-linearity cancellation for switches for audio and other applications

Certain aspects of the present disclosure generally relate to methods and apparatus for providing overvoltage protection for circuitry coupled to connector ports, such as USB-C ports. One example circuit for overvoltage protection between a connector port and a signal node corresponding to the connector port generally includes a first switch having a first terminal for coupling to the connector port and having a second terminal for coupling to the signal node; a first resistive element coupled in parallel with the first switch; a first transient protection circuit coupled between the signal node and a reference potential node; and a control circuit having an input coupled to the signal node and having a first output coupled to a control input of the first switch.

Overvoltage protection scheme for connector ports

A power amplifier provides reduction of click and pop in audio applications. The power amplifier includes a first amplifier and an auxiliary amplifier. The auxiliary amplifier is used to ramp the power amplifier output from ground to an offset voltage to reduce the 'click and pop' sound. The first amplifier and the auxiliary amplifier having a shared feedback loop. An output of the first amplifier and an output of the auxiliary amplifier may be switchably coupled to the shared feedback loop. A wave generator controls a switch to couple the first amplifier output or the auxiliary amplifier output to the shared feedback loop.

Audio power amplifier for reduced click and pop (CnP)

An apparatus for power supply mode switching includes a first voltage regulator to output a first voltage, a second voltage regulator to output a second voltage, a third voltage regulator to output a third voltage, an electronic load, a first switch between the first voltage regulator and the electronic load, a second switch between the second voltage regulator and the electronic load, and a third switch between the third voltage regulator and the electronic load. And, a method for power supply mode switching includes supplying power to an electronic load with a first voltage; switching to a second voltage; maintaining coupling of the electronic load with the second voltage while a voltage across the electronic load is less than a reference voltage; and switching to a third voltage when the voltage is greater than or equal to the reference voltage and the third voltage is less than the second voltage.

Low-glitch switch control for mode switching of memory cells

A digital-to-analog converter has both a plurality of DAC stages and a plurality of dummy stages. Each DAC stage causes a glitch or disturbance to a pair of reference voltages when the DAC stage changes its switching state. Each dummy stage also causes a similar glitch or disturbance to the pair of reference voltages when the dummy stage changes its switching state. The dummy stages are controlled to change their switching state responsive to how many DAC stages change their switching state such that a total glitch induced onto the reference voltages remains substantially constant across a succession of digital words converted by the digital-to-analog converter into an analog output signal.

Digital-to-analog converter with glitch-irrelevant reference voltage to increase linearity

An apparatus includes a reference voltage circuit having a bandgap input and a reference voltage output. The apparatus also includes a digital-to-analog converter (DAC) coupled to the reference voltage output and having a digital signal input. The apparatus includes an amplifier having a first input coupled to an output of the DAC. The first input is coupled to an output of the amplifier via a feedback resistor. The apparatus includes a resistor coupled to the reference voltage output and having a body terminal coupled to the output of the amplifier.

Amplifier with nonlinearity compensation

An example apparatus includes an output jack including a ground pole and a power output pole, a power supply circuit configured to generate a power signal, a coupler circuit operably coupled to the ground pole and the power output pole of the output jack, such that the coupler circuit is configured to couple the power signal with a noise signal on the ground pole to generate a combined output signal on the power output pole.

Cancelation of induced ground noise in a headphone output

An apparatus includes a resistor having an input coupled to an output of an amplifier. The apparatus also includes a feedback circuit coupled to an output of the resistor and to an input of the amplifier. The feedback circuit includes a first component of a voltage divider.

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San Diego, CA, United States of America

Vijayakumar Dhanasekaran