An analog front-end device includes an amplifier circuit, a first gain control circuit, and a tracking circuit. The amplifier circuit is configured to generate a first output signal according to a first input signal. The first gain control circuit is configured to set a first electronic component according to a first gain control signal and transmit the first input signal to a first input terminal of the amplifier circuit via the first electronic component, in which a terminal of the first electronic component is selectively coupled to the first input terminal or a first predetermined node. The tracking circuit is configured to adjust a level of the first predetermined node according to a level of the first input terminal, in order to reduce a voltage difference between the first input terminal and the first predetermined node.

An electronic device may include wireless circuitry with a processor, a transceiver, an antenna, and a front-end module coupled between the transceiver and the antenna. The front-end module may include one or more radio-frequency amplifiers for amplifying a radio-frequency signal. The radio-frequency amplifier may include input transistors cross-coupled with capacitance neutralization transistors and/or coupled to cascode transistors. One or more n-type gain adjustment transistors may be coupled to source terminals of the capacitance neutralization transistors. One or more p-type gain adjustment transistors may be coupled to source terminals of the cascode transistors. One or more processors in the electronic device can selectively activate one or more of the gain adjustment transistors to reduce the gain of the radio-frequency amplifier without degrading noise performance and without altering the in-band frequency response of the radio-frequency amplifier.

An integrated circuit includes an oscillator and a power amplifier. The oscillator includes a first node, a second node, and a network of one or more reactive components coupled between the first node and the second node. The power amplifier includes a first input coupled to the first output of the oscillator, a second input coupled to the second output of the oscillator, and an output. The power amplifier includes a coarse gain control circuit, a first amplifier stage, and a second amplifier stage.

Envelope tracking power amplifiers with advanced gain shaping are provided. In certain implementations, a power amplifier system includes a power amplifier that amplifies a radio frequency (RF) signal and an envelope tracker that controls a voltage level of a supply voltage of the power amplifier based on an envelope of the RF signal. The power amplifier system further includes a gain shaping circuit that generates a gain shaping current that changes with the voltage level of the supply voltage from the envelope tracker. For example, the gain shaping circuit can include an analog look-up table (LUT) mapping a particular voltage level of the supply voltage to a particular current level of gain shaping current. Additionally, the gain shaping circuit biases the power amplifier based on the gain shaping current.

A method for calibrating an isolator product includes receiving a calibration signal on a differential pair of nodes of a receiver signal path of a first integrated circuit die of the isolator product. The method includes generating a diagnostic signal having a level corresponding to an average amplitude of the calibration signal on the differential pair of nodes. The method includes configuring a programmable receiver signal path based on the diagnostic signal. Generating the diagnostic signal may include providing an analog signal based on a full-wave rectified version of the calibration signal on the differential pair of nodes. Generating the diagnostic signal may include converting the analog signal to a digital signal.

An apparatus for amplifying an audio source includes a speaker and a chip. The chip includes a processor configured to generate a signal and an amplifier element configured to amplify the signal into an amplified signal. The chip further includes a current monitor configured to monitor the current of the amplified signal prior to the amplified signal being output from the chip to the speaker and a voltage monitor configured to monitor the voltage of the amplified signal prior to the amplified signal being output from the chip to the speaker. The processor of the chip is configured to control a power of the amplified signal output from the chip to the speaker based at least on the current and the voltage.

Provided is a regulator circuit that supplies an output voltage to a load, the regulator circuit including an error amplifier that amplifies an error between a feedback signal and a reference voltage, and an output stage that changes the output voltage, the error amplifier including a first transconductance amplifier that receives the feedback signal and the reference voltage, a first resistance connected to an output node of the first transconductance amplifier and a ground, a first capacitor connected in parallel to the first resistance, a second transconductance amplifier that receives a voltage of the output node of the first transconductance amplifier and the feedback signal, a second resistance connected to an output node of the second transconductance amplifier and a ground, a second capacitor connected in parallel to the second resistance, and a zero controller that controls a gain of the second transconductance amplifier.

Provided is a regulator circuit that supplies an output voltage to a load, the regulator circuit including an error amplifier that amplifies an error between a feedback signal and a reference voltage, and an output stage that changes the output voltage, the error amplifier including a first transconductance amplifier that receives the feedback signal and the reference voltage, a first resistance connected to an output node of the first transconductance amplifier and a ground, a first capacitor connected in parallel to the first resistance, a second transconductance amplifier that receives a voltage of the output node of the first transconductance amplifier and the feedback signal, a second resistance connected to an output node of the second transconductance amplifier and a ground, a second capacitor connected in parallel to the second resistance, and a zero controller that controls a gain of the second transconductance amplifier.

A power amplifier circuit includes a first amplifier transistor, a first nonlinear element, and a current control circuit. The first amplifier transistor has a base or a gate into which a first signal is input, a collector or a drain from which a signal resulting from amplification of the first signal is output, and an emitter or a source that is grounded. The first nonlinear element is connected between the collector or the drain of the first amplifier transistor and the base or the gate of the first amplifier transistor. The current control circuit is connected between the ground and the base or the gate of the first amplifier transistor and controls current flowing through the first nonlinear element.

Methods, systems, and apparatuses are described herein for improved processing audio in a video stream. A system may split audio in a frame of video content into multiple bands based on their audio levels. The system may then dynamically compress and dynamically normalize the audio level in each band. When dynamically compressing the bands, the system may determine, based on stored information, what audio level range is acceptable for an end user and may smooth and maintain the ranges of the audio to be within the acceptable range. The system may include the dynamically normalized and dynamically compressed frames as a second audio track in the video content. A computing device receiving the video content may select the second audio track during playback. If an end user selects the second audio track, the video is delivered with the modified sound of the second audio track.