A signal processer is configured to decrease total harmonic distortion plus noise of an output signal generated from an input signal. The signal processer includes a mixer, a pulse-width modulator, a power stage circuit, and a feedback circuit. The mixer is configured to mix the input signal and a feedback signal to generate a mixed signal. The pulse-width modulator is configured to module the mixed signal to generate a modulated signal and output the modulated signal from an output terminal of the pulse-width modulator. The power stage circuit is configured to amplify the modulated signal to generate the output signal and output the output signal from an output terminal of the power stage circuit. The feedback circuit is configured to generate a feedback signal selectively according to the modulated signal or the output signal.

This application relates to ADC circuitry. An ADC circuit (200) has first and second conversion paths (201a, 201b) for converting analogue signals to digital and is operable in first and second modes. In the first mode, the first and second conversion paths are connected to respective first and second input nodes (202a, 202b) to receive and convert full scale first and second analogue input signals (Ain1, Ain2) to separate digital outputs (Dout1, Dout2). In the second mode, the first and second conversion paths are both connected to the first input node (202a), to convert the first analogue input signal (Ain1) to respective first and second digital signals, and the first and second conversion paths are configured for processing different signal levels of the first analogue input signal. A selector (207) select the first digital signal or the second digital to be output as an output signal based on an indication of amplitude of the first analogue input signal.

A circuit includes first and second gain stages and an output transistor. The second gain stage includes a transconductance amplifier and a variable impedance circuit coupled to an output of the transconductance amplifier. The variable impedance circuit is configured to implement a first impedance level at frequencies below a first frequency threshold and to implement a second impedance level at frequencies above a second frequency level. The first impedance level is larger than the second impedance level. The output transistor has a control input coupled to the variable impedance circuit. At frequencies above the second frequency threshold, the second impedance level is configured to be inversely related to current through the output transistor.

A guitar holder with a built-in guitar amplifier for enabling convenient guitar practice and/or play with a compact, space-saving footprint. The guitar holder may comprise any of a variety of guitar holders, including but not limited to a guitar stand and/or a guitar wall hanger.

A display apparatus and a method for processing audio are provided, the display apparatus includes a circuit board provided with a hybrid circuit, a filter circuit and a speaker; the hybrid circuit is configured to receive an original audio signal and superpose a first sub-signal of the original audio signal on a second sub-signal of the original audio signal to obtain a hybrid audio signal; the first sub-signal includes at least one channel of audio signal, the second sub-signal includes at least two channels of audio signal; the filter circuit is configured to filter the hybrid audio signal according to a frequency characteristic of the first sub-signal and the second sub-signal to obtain a restored original audio signal; and the speaker, connected with the filter circuit, is configured to output the restored original audio signal.

A transducer system has a transducer configured to receive an incident signal and produce an output signal as a function of the incident signal. As known in the art, the output signal has a −3 dB point. The transducer system also has circuitry operatively coupled with the transducer. The circuitry includes an amplifier with an output configured to produce an amplified signal as a function of the output signal. In addition, the circuitry further has a positive feedback loop and a negative feedback loop that both are electrically coupled between the transducer and the amplifier. The positive feedback loop is configured to move the −3 dB point in a first frequency direction. Conversely, the negative feedback loop is configured to move the −3 dB point in a second frequency direction. Preferably, the first and second frequency directions are different.

An electronic circuit includes a microcontroller and a DSP (Digital Signal Processor), where the differential of the electronic circuit now proposed, is to transfer the output power to one of the different channels in a free and individual way, from one side to the other, being able to equalize and amplify each channel (speaker), permitting the power division not necessarily equal to said channels.

A packaged semiconductor die may include a package terminal array comprising a plurality of terminals, wherein a spacing between the plurality of terminals of the ball grid array is less than 0.5 mm. First and second high-voltage circuits of the die may output a differential signal to a first and second terminal that may exceed 15 volts, in which the first high-voltage circuit and the second high-voltage circuit are positioned symmetrically around an axis and in which the first terminal and the second terminal are located at an edge of the package terminal array. A low-voltage circuit may be coupled to a third terminal and positioned between the first high-voltage circuit and the second high-voltage circuit, wherein the low-voltage circuit comprises circuitry organized in columns aligned along an axis and having a width defined by a fraction of the terminal spacing pitch.

An audio device includes a network interface, an amplifier that amplifies an audio signal received through the network interface, and a processor configure to obtain an output value of a signal from the amplifier and sends the output value of the signal through the network interface.

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.