Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Certain aspects of the present disclosure generally relate to methods and apparatus for driving haptic actuators. An example actuator driver circuit generally includes a driver and calibration circuitry. The driver has at least one output for coupling to at least one input of an actuator. The calibration circuitry is configured to: detect a phase of a voltage signal at the at least one output of the driver, detect a phase of a current signal at the at least one output of the driver, determine a phase difference between the phase of the voltage signal and the phase of the current signal, and adjust a frequency of an oscillating signal for the driver, based at least in part on the phase difference.

Abstract: Certain aspects of the present disclosure are generally directed to circuitry and techniques for current sensing. For example, certain aspects provide a circuit for signal amplification including a first amplifier, a second amplifier, and a third amplifier. The circuit also includes a first capacitive element coupled between a first output of the first amplifier and a first input of the third amplifier, a second capacitive element coupled between a second output of the first amplifier and a second input of the third amplifier, a third capacitive element coupled between a first output of the second amplifier and the first input of the third amplifier, and a fourth capacitive element coupled between a second output of the second amplifier and the second input of the third amplifier.

Abstract: An apparatus is disclosed for reducing resistor conductivity modulation during amplification. In an example aspect, the apparatus includes a power amplifier circuit comprising a first pair of resistors, a digital-to-analog converter comprising a second pair of resistors, a reference generation circuit comprising a third pair of resistors, and a scaling circuit. The scaling circuit is configured to accept a common-mode reference voltage and a common-mode output voltage. The scaling circuit is also configured to provide a first voltage at body terminals of the first pair of resistors, a second voltage at body terminals of the second pair of resistors, and a third voltage at body terminals of the third pair of resistors such that a summation of the first voltage and the third voltage reduced by the second voltage is approximately equal to an average of the common-mode reference voltage and the common-mode output voltage.

Abstract: Certain aspects of the present disclosure are generally directed to circuitry and techniques for current sensing. For example, certain aspects provide a circuit for signal amplification including a first amplifier, a second amplifier, and a third amplifier. The circuit also includes a first capacitive element coupled between a first output of the first amplifier and a first input of the third amplifier, a second capacitive element coupled between a second output of the first amplifier and a second input of the third amplifier, a third capacitive element coupled between a first output of the second amplifier and the first input of the third amplifier, and a fourth capacitive element coupled between a second output of the second amplifier and the second input of the third amplifier.

Abstract: Certain aspects of the present disclosure generally relate to methods and apparatus for driving haptic actuators. An example actuator driver circuit generally includes a driver and calibration circuitry. The driver has at least one output for coupling to at least one input of an actuator. The calibration circuitry is configured to: detect a phase of a voltage signal at the at least one output of the driver, detect a phase of a current signal at the at least one output of the driver, determine a phase difference between the phase of the voltage signal and the phase of the current signal, and adjust a frequency of an oscillating signal for the driver, based at least in part on the phase difference.

Abstract: Certain aspects of the present disclosure are generally directed to circuitry and techniques for current sensing. For example, certain aspects provide a circuit for signal amplification including a first amplifier, a second amplifier, and a third amplifier. The circuit also includes a first capacitive element coupled between a first output of the first amplifier and a first input of the third amplifier, a second capacitive element coupled between a second output of the first amplifier and a second input of the third amplifier, a third capacitive element coupled between a first output of the second amplifier and the first input of the third amplifier, and a fourth capacitive element coupled between a second output of the second amplifier and the second input of the third amplifier.

Abstract: An audio codec system includes an audio driver path coupled to a first node of the audio codec system. A first terminal of a sense resistor external to the audio codec system is coupled to the first node and a second terminal of the sense resistor is coupled to an auxiliary device load. The audio codec system includes a second path having a first bias circuit, a second bias circuit and an off-chip voltage reference. The first bias circuit is coupled to a second node of the audio codec system. The second bias circuit is coupled to a third node of the audio codec system. The off-chip voltage reference is associated with the auxiliary device load coupled between the first bias circuit and the second bias circuit.

Abstract: An audio codec system includes an audio driver path coupled to a first node of the audio codec system. A first terminal of a sense resistor external to the audio codec system is coupled to the first node and a second terminal of the sense resistor is coupled to an auxiliary device load. The audio codec system includes a second path having a first bias circuit, a second bias circuit and an off-chip voltage reference. The first bias circuit is coupled to a second node of the audio codec system. The second bias circuit is coupled to a third node of the audio codec system. The off-chip voltage reference is associated with the auxiliary device load coupled between the first bias circuit and the second bias circuit.

Abstract: A device for grounding pop-click noise may include an output block configured to generate an output signal at an output node. A switch circuit coupled to the output node may be configured to be operable to couple the output node to a ground potential. The switch circuit may include a first and a second transistor. A drain, a source, and a gate node of the first transistor may be coupled to the output node, a drain node of the second transistor, and a first control signal, respectively. A drain, a source, and a gate node of the second transistor may be coupled to a source node of the first transistor, the ground potential, and a second control signal, respectively. The first and the second control signals may operate the switch circuit to couple the output node to the ground potential during a pre-determined period associated with the pop-click noise.

Abstract: Various examples are provided for voltage protection of semiconductor devices. In one example, among others, a circuit includes a MOS device, a protective device connected between the MOS device and an output voltage connection, and gate protection circuitry configured to provide a bias voltage to a gate of the protective device. The bias voltage includes a DC bias component and an AC bias component that synchronously varies with a voltage of the output voltage connection. Another example includes a plurality of protective devices connected between the MOS device and the output voltage connection. The gate protection circuitry may be configured to provide a plurality of bias voltages to the plurality of protective devices. In another example, a method includes attenuating an output voltage, combining the attenuated output voltage with a constant offset voltage to generate a gate bias voltage, and providing the gate bias voltage to a protective device.

Abstract: A device for grounding pop-click noise may include an output block configured to generate an output signal at an output node. A switch circuit coupled to the output node may be configured to be operable to couple the output node to a ground potential. The switch circuit may include a first and a second transistor. A drain, a source, and a gate node of the first transistor may be coupled to the output node, a drain node of the second transistor, and a first control signal, respectively. A drain, a source, and a gate node of the second transistor may be coupled to a source node of the first transistor, the ground potential, and a second control signal, respectively. The first and the second control signals may operate the switch circuit to couple the output node to the ground potential during a pre-determined period associated with the pop-click noise.

Abstract: Various examples are provided for voltage protection of semiconductor devices. In one example, among others, a circuit includes a MOS device, a protective device connected between the MOS device and an output voltage connection, and gate protection circuitry configured to provide a bias voltage to a gate of the protective device. The bias voltage includes a DC bias component and an AC bias component that synchronously varies with a voltage of the output voltage connection. Another example includes a plurality of protective devices connected between the MOS device and the output voltage connection. The gate protection circuitry may be configured to provide a plurality of bias voltages to the plurality of protective devices. In another example, a method includes attenuating an output voltage, combining the attenuated output voltage with a constant offset voltage to generate a gate bias voltage, and providing the gate bias voltage to a protective device.