Abstract: In a general aspect, a circuit can include an input circuit configured to receive an input signal, and an amplifier circuit coupled with the input circuit. The amplifier circuit can include an amplifier, and first and second feedback paths. The first feedback path can be from a positive output to a negative input of the amplifier, and the second feedback path can be from a negative output to a positive input of the first amplifier. The circuit can also include a loop circuit configured to provide a local feedback loop for the first amplifier and configured to control current flow into the positive input of the first amplifier and current flow into the negative input of the first amplifier. The circuit can also include a control circuit that is configured to enable the loop circuit in response to a magnitude of the input signal exceeding a threshold.

Abstract: In a general aspect, a circuit can include an input circuit configured to receive an input signal, and an amplifier circuit coupled with the input circuit. The amplifier circuit can include an amplifier, and first and second feedback paths. The first feedback path can be from a positive output to a negative input of the amplifier, and the second feedback path can be from a negative output to a positive input of the first amplifier. The circuit can also include a loop circuit configured to provide a local feedback loop for the first amplifier and configured to control current flow into the positive input of the first amplifier and current flow into the negative input of the first amplifier. The circuit can also include a control circuit that is configured to enable the loop circuit in response to a magnitude of the input signal exceeding a threshold.

Abstract: In one general aspect, an apparatus can include a first terminal, a second terminal, and a resistive element extending between the first terminal and the second terminal. The resistive element can include a first via in contact with a first segment of a first metal layer and a first segment of a second metal layer, and can include a second via in contact with the first segment of the second metal layer and a second segment of the first metal layer. The apparatus can also include a third via in contact with the second segment of the first metal layer and a third segment of the second metal layer.

Abstract: In a general aspect, a circuit can include an amplifier circuit including a first amplifier, a first feedback path, and a second feedback path. The first feedback path can provide a feedback path from a positive output of the first amplifier to a negative input of the first amplifier. The second feedback path can provide a feedback path from a negative output of the first amplifier to a positive input of the first amplifier, The circuit can also include a loop circuit including a second amplifier, The loop circuit can be configured to provide a local feedback loop for the first amplifier and configured to control current flow into the positive input of the first amplifier and into the negative input of the first amplifier.

Abstract: In a general aspect, a circuit can include an amplifier circuit including a first amplifier, a first feedback path, and a second feedback path. The first feedback path can provide a feedback path from a positive output of the first amplifier to a negative input of the first amplifier. The second feedback path can provide a feedback path from a negative output of the first amplifier to a positive input of the first amplifier. The circuit can also include a loop circuit including a second amplifier. The loop circuit can be configured to provide a local feedback loop for the first amplifier and configured to control current flow into the positive input of the first amplifier and into the negative input of the first amplifier.

Abstract: In a general aspect, a system can include a fully differential amplifier circuit that includes a first amplifier, and first and second feedback paths. The first feedback path can provide a feedback path from a positive output of the first amplifier to a negative input of the first amplifier. The second feedback path can provide a feedback path from a negative output of the first amplifier to a positive input of the first amplifier. The system can include a chopper clock circuit configured to output a variable duty cycle chopper clock signal. The system can include a common mode loop circuit including a second amplifier and chopper switches. The common mode loop circuit can be configured as a local feedback loop for the first amplifier. The chopper switches can be configured to receive the chopper clock signal and control current flow into the positive and negative inputs.

Abstract: In a general aspect, an apparatus can include a signal analyzer configured to analyze a signal associated with a processing pipeline, and a dynamic element matching (DEM) selection module configured to select a DEM algorithm from a plurality of DEM algorithms based on the analysis performed by the signal analyzer. The apparatus can include a set of circuit elements where each circuit element from the set of circuit elements has the same logical configuration, and a circuit element selection module configured to select a subset of the set of circuit elements based on the selected DEM algorithm.

Abstract: In one general aspect, an apparatus can include a first terminal, a second terminal, and a resistive element extending between the first terminal and the second terminal. The resistive element can include a first via in contact with a first segment of a first metal layer and a first segment of a second metal layer, and can include a second via in contact with the first segment of the second metal layer and a second segment of the first metal layer. The apparatus can also include a third via in contact with the second segment of the first metal layer and a third segment of the second metal layer.

Abstract: Methods and apparatus for calibrating an audio system including headset coupled to an electronic device via an audio dongle. In an example, a circuit configured to couple a Universal Serial Bus (USB) audio dongle with an audio circuit of an electronic device can include a first impedance configured to couple with a first audio channel of the audio circuit, a second impedance coupled in series with the first impedance and configured to couple with a second audio channel of the audio circuit, a third impedance coupled to a ground sense channel and to a node common to the first impedance and the second impedance, and a controller configured to initiate a first signal on the first channel, to monitor crosstalk of the first signal on the second audio channel and to adjust a setting of the third impedance to reduce the crosstalk.

Abstract: This document discusses, among other things, a detection circuit configured to receive an output of a window comparator over a range of input values and to measure a difference between first and second thresholds of the window comparator, and a trim circuit configured to adjust at least one of the first or second thresholds using the measured difference between the first and second thresholds.

Abstract: An apparatus comprises an integrated circuit (IC) comprising an external IC connection, an IC substrate connection, a voltage clamp circuit and an under voltage circuit. The voltage of the IC substrate connection is set to a first voltage when a voltage of the external connection of the IC is within a normal operating voltage range. The voltage clamp circuit is configured to clamp the voltage supply of one or more circuits internal to the IC to within a normal operating voltage range when the voltage of the external IC connection exceeds the normal operating voltage range. The under voltage circuit is communicatively coupled to the clamp circuit and configured to set the voltage of the substrate to a second voltage when the voltage at the external IC connection of the IC is less than zero volts.

Abstract: Methods and apparatus for calibrating an audio system including headset coupled to an electronic device via an audio dongle. In an example, a circuit configured to couple a Universal Serial Bus (USB) audio dongle with an audio circuit of an electronic device can include a first impedance configured to couple with a first audio channel of the audio circuit, a second impedance coupled in series with the first impedance and configured to couple with a second audio channel of the audio circuit, a third impedance coupled to a ground sense channel and to a node common to the first impedance and the second impedance, and a controller configured to initiate a first signal on the first channel, to monitor crosstalk of the first signal on the second audio channel and to adjust a setting of the third impedance to reduce the crosstalk.

Abstract: The present subject matter refers to apparatus and methods for identifying a resistance level of a resistor. In an example, circuit configured to identify a resistor can include a plurality of current sources, each current source selectively coupled to the resistor to generate a resistor voltage, a comparator configured to compare the resistor voltage and a reference voltage, and to provide an output indicative of the comparison, and a controller configured to selectively couple a first one or more current sources of the plurality of current sources to the resistor, and to selectively couple a second one or more current sources of the plurality of current sources to the resistor in response to the output indicative of the comparison.

Abstract: This application discusses among other things, apparatus and method for transmitting data with an analog signal without significantly distorting the analog signal. In an example, an apparatus can include an audio channel, a capacitor coupled to a first conductor of the audio channel, the capacitor configured to couple an analog representation of a digital data signal with an analog audio signal on the audio channel, and a frequency modulator configured to receive the digital data signal and to modulate a frequency of an output signal of the frequency modulator based on a logic level of the digital data signal, wherein the analog representation of the digital data signal includes the frequency of the output signal of the frequency modulator.

Abstract: This application discusses methods and apparatus for a data-on-supply repeater. In an example, a repeater can include a repeater circuit configured to receive a power signal at an input and to provide a representation of a received analog data signal at an output, a direction detector configured to receive the power signal from a first bus conductor of a plurality of bus conductors, to identify the first buss conductor of the plurality of bus conductors as a transmitting conductor, and to provide an output indicative of the transmitting conductor, a first input multiplexer configured to couple the transmitting conductor to the input of the repeater circuit in response to the output of the direction detector, and an output multiplexer configured to couple the output of the repeater circuit to a second bus conductor of the plurality of bus conductors, wherein the second bus conductor is different than the transmitting conductor.

Abstract: This document discusses, among other things, apparatus and methods for a detection circuit. In an example, the detection circuit can include a voltage divider configured to receive a first supply voltage from an external device coupled to the detection circuit, first and second transistors configured to receive a control voltage from the voltage divider and to couple an output to ground when the control voltage exceeds a first threshold, and a bias circuit configured to bias the first transistor to set the first threshold.

Abstract: A detection circuit can be configured to receive a digital value from an identification register and to determine a resistance at a conducting terminal of an audio or video jack plug using the digital value. The detection circuit can include a current source that outputs a current according to the digital value from the identification register and a comparator that compares a reference voltage to a voltage created by the current source across the resistance at the conducting terminal of the audio or video jack plug. A control logic circuit can be configured to store the digital value in the identification register, generate an interrupt signal to cause a processor to read the digital value, and identify a function of an accessory device including the audio or video jack plug, when the detection circuit determines the resistance at the conducting terminal of the audio or video jack plug.

Abstract: This document discusses, among other things, systems and methods to provide an internal supply rail with over voltage protection using a host power source, an external power source, and a switch configured to receive indications of host and external power source validity. In an example, the switch can be configured to provide the internal supply rail using the host power source when the indication of host power source validity indicates a valid host power source and the external power source when the indication of host power source validity indicates an invalid host power source and the indication of external power source validity indicates a valid external power source.

Abstract: This application discusses methods and apparatus for a data-on-supply repeater. In an example, a repeater can include a repeater circuit configured to receive a power signal at an input and to provide a representation of a received analog data signal at an output, a direction detector configured to receive the power signal from a first bus conductor of a plurality of bus conductors, to identify the first buss conductor of the plurality of bus conductors as a transmitting conductor, and to provide an output indicative of the transmitting conductor, a first input multiplexer configured to couple the transmitting conductor to the input of the repeater circuit in response to the output of the direction detector, and an output multiplexer configured to couple the output of the repeater circuit to a second bus conductor of the plurality of bus conductors, wherein the second bus conductor is different than the transmitting conductor.

Abstract: This document discusses, among other things, systems and methods to provide an internal supply rail with over voltage protection using a host power source, an external power source, and a switch configured to receive indications of host and external power source validity. In an example, the switch can be configured to provide the internal supply rail using the host power source when the indication of host power source validity indicates a valid host power source and the external power source when the indication of host power source validity indicates an invalid host power source and the indication of external power source validity indicates a valid external power source.