Abstract: A circuit for generating a signal comprising a first transistor having a drain, a gate and a source. A second transistor having a drain, a source and a gate coupled to the gate of the first transistor to form a current mirror. A current source coupled to the source of the first transistor. A diode-connected transistor having a drain coupled to the source of the second transistor, a source and a gate that forms an output. A variable resistor having a first terminal coupled to the source of diode-connected transistor and a second terminal. A capacitor coupled to the second terminal of the variable resistor.

Abstract: A variable ramp up/down gain in a pre-power stage block of an audio amplifier may be used to reduce audible pops and clicks output by the audio amplifier. A controller may adjust the variable ramp up/down gain during operation of the audio amplifier. The variable ramp up/down gain may be implemented as a pulse width modulation (PWM) modulator/generator with a ramp-up and ramp-down gain under control of the controller. The variable ramp up/down gain smooths transitions of the offset between a pre-power stage block and a feedback loop and thus can reduce audible pops and clicks by reducing the offset that is amplified in the power stage block of the audio amplifier.

Abstract: A system for detecting a jack configuration comprising a first plurality of switches configured to couple a first headphone jack position to ground. A second plurality of switches configured to couple a second headphone jack position to ground. A microphone bias circuit for applying a microphone bias signal to the second headphone jack position when the first headphone jack position is coupled to ground, and for applying the microphone bias signal to the first headphone jack position when the second headphone jack position is coupled to ground.

Abstract: A level shifter comprising a first driver transistor for receiving an input signal. A gate-controlled transistor coupled to the first driver transistor. A second driver transistor coupled to the gate controlled transistor. An output coupled to the second driver transistor, wherein the gate-controlled transistor is for receiving a predetermined gate voltage when the output voltage exceeds a predetermined value.

Abstract: In accordance with embodiments of the present disclosure, systems and methods may include a switch coupled at its gate terminal to an input signal voltage, the input signal voltage for controlling a gate voltage of a gate terminal of a driver device coupled at its non-gate terminals between a rail voltage and an output node. The systems and methods may also include a diode having a first terminal and a second terminal, the diode coupled to a non-gate terminal of the switch such that when the switch is enabled, the first terminal is electrically coupled to the gate terminal of the driver device and the second terminal is electrically coupled to the output node.

Abstract: The systems and methods described herein allow greater access to a banking platform via a mobile device. The customer can initiate a financial transaction using a mobile device, a bank can inform the customer of the nearest financial transaction terminal to perform that service, and the customer can complete that financial transaction at the financial transaction terminal using the mobile device as a user interface. While conventional systems may use a mobile device to transmit payment information at a point of sale terminal of a brick-and-mortar merchant, the embodiments described herein can allow a customer to conduct a transaction at a financial transaction terminal using the mobile device to initiate a transaction at a location away from a financial transaction terminal, to locate the nearest financial transaction terminal providing the required services, and as a user interface while communicating with the financial transaction terminal.

Abstract: A controller of a boost converter may be configured to dynamically adjust conditions within the boost converter by monitoring conditions in the boost converter. For example, the controller may determine an current inductance value for an inductor of the boost converter by monitoring a current through the inductor. When the inductance value of the inductor is known, a slope compensation value may be used in determining a transition time between charging the inductor of the boost converter and discharging the inductor.

Abstract: Audio amplification may be improved by controlling an audio amplifier based on the audio signal being amplified. For example, when the audio signal level increases or decreases, a boost voltage provided to an audio amplifier by a boost converter may also be increased or decreased. In another example, when the audio signal level decrease below a certain level, the audio amplifier may be switched from amplifying the audio signal with a boost converter input to amplifying the audio signal with a low voltage input. Control of the audio amplifier may be implemented in a digital boost converter controller coupled to the boost converter and/or the audio amplifier.

Abstract: In accordance with embodiments of the present disclosure, systems and methods may include a switch coupled at its gate terminal to an input signal voltage, the input signal voltage for controlling a gate voltage of a gate terminal of a driver device coupled at its non-gate terminals between a rail voltage and an output node. The systems and methods may also include a diode having a first terminal and a second terminal, the diode coupled to a non-gate terminal of the switch such that when the switch is enabled, the first terminal is electrically coupled to the gate terminal of the driver device and the second terminal is electrically coupled to the output node.

Abstract: An audio processing system that includes an audio filter having one or more elements capable of having state, such as a capacitor, an inductor or a delay. A saturation detector is configured to detect saturation of the audio filter and to generate an output when saturation of the filter is detected, such as a switch control signal. A switch is connected to the audio filter and the saturation detector, wherein the state of one or more of the elements of the audio filter is changed when the saturation detector provides the output to the switch, such as when the switch shorts the element and causes the energy stored in the element to be dissipated.

Abstract: A level shifter comprising a first driver transistor for receiving an input signal. A gate-controlled transistor coupled to the first driver transistor. A second driver transistor coupled to the gate controlled transistor. An output coupled to the second driver transistor, wherein the gate-controlled transistor is for receiving a predetermined gate voltage when the output voltage exceeds a predetermined value.

Abstract: A dual-voltage receiver, comprising a voltage detector. A high voltage Schmitt trigger coupled to the voltage detector. A low voltage Schmitt trigger coupled to the voltage detector. A combined level shifter coupled to the high voltage Schmitt trigger and the low voltage Schmitt trigger, wherein the high voltage Schmitt trigger is on and the low voltage Schmitt trigger is off when the voltage detector outputs a high voltage detect signal.

Abstract: A level shifter comprising a first driver transistor receiving an input signal. A gate-controlled transistor coupled to the first driver transistor. A second driver transistor coupled to the gate controlled transistor. An output coupled to the second driver transistor, wherein the gate-controlled transistor is for receiving a predetermined gate voltage when the output voltage exceeds a predetermined value.

Abstract: A device comprising a detector configured to receive an indication from a terminal of a connector and to determine whether the indication matches an expected result. One or more first switches are configured to connect one or more speaker transducers to the connector if the indication is false. One or more second switches are configured to connect the one or more speaker transducers to a digital output converter if the indication is true. The device can also include one or more third switches configured to connect one or more microphone elements to the connector if the indication is false, and one or more fourth switches configured to connect one or more microphones to a digital input converter if the indication is true. The input and output converters can be stand alone or part of a digital signal processor.

Abstract: A grounding switch is described which operates properly even in the presence of negative voltages on a signal line. The grounding switch uses isolated field effect transistors that have their substrates tied to different voltages. The isolated field effect transistor has a gate voltage and substrate voltage which can be pulled down to a negative voltage when the signal line has a negative voltage allowing the switch to remain open even with a negative voltage.

Abstract: High linearity is essential in audio circuitry. As sampling rates for audio applications are needed, high speed and high linearity are needed in analog and mixed signal portions of audio circuitry such as in current mirrors. A current mirror employs two current paths in an output. The first current path is driven by a fast acting transistor through a resistor. The second current path is driven by a differential amplifier coupled to another transistor through another resistor. The second current path is used to maintain linearity by causing the voltage across both transistors to be the same.

Abstract: A reconfigurable amplifier comprising a first operational amplifier having two inputs and an output. A second operational amplifier having two inputs and an output. A plurality of switches coupled to the two inputs and the output of the first operational amplifier and the two inputs and the output of the second operational amplifier, wherein a first configuration of the plurality of switches causes the first operational amplifier and the second operational amplifier to operate as an inverting differential input amplifier, and wherein a second configuration of the plurality of switches causes the first operational amplifier and the second operational amplifier to operate as a non-inverting differential input instrumentation amplifier.

Abstract: A dual-voltage receiver, comprising a voltage detector. A high voltage Schmitt trigger coupled to the voltage detector. A low voltage Schmitt trigger coupled to the voltage detector. A combined level shifter coupled to the high voltage Schmitt trigger and the low voltage Schmitt trigger, wherein the high voltage Schmitt trigger is on and the low voltage Schmitt trigger is off when the voltage detector outputs a high voltage detect signal.

Abstract: A grounding switch is described which operates properly even in the presence of negative voltages on a signal line. The grounding switch uses isolated field effect transistors that have their substrates tied to different voltages. The isolated field effect transistor has a gate voltage and substrate voltage which can be pulled down to a negative voltage when the signal line has a negative voltage allowing the switch to remain open even with a negative voltage.

Abstract: Challenges to the implementation of equalization in the 2.1 environment arise from the constraints imposed by HD audio requirements and Windows® Vista™. A hybrid software hardware solution overcomes many of the challenges by exploiting the software capability for equalization and using a hardware codec to perform the separation into high frequency and low frequency audio streams needed to drive stereo speakers and a subwoofer.