A multi-gain LNA with inductive source degeneration is presented. The inductive source degeneration is provided via a tunable degeneration network that includes an inductor in parallel with one or more switchable shunting networks. Each shunting network includes a shunting capacitor that can selectively be coupled in parallel to the inductor. A capacitance of the shunting capacitor is calculated so that a combined impedance of the inductor and the shunting capacitor at a narrowband frequency of operation is effectively an inductance. The inductance is calculated according to a desired gain of the LNA. According to one aspect, the switchable shunting network includes a resistor in series connection with the shunting capacitor to provide broadband frequency response stability of the tunable degeneration network. According to another aspect, the LNA includes a plurality of selectable branches to further control gain of the LNA.

An amplifier circuit includes: an operational amplifier that includes two input terminals and an output terminal; a voltage-dividing resistor circuit electrically connected to the output terminal and that includes a voltage-dividing terminal that outputs a potential obtained by voltage-dividing a potential of the output terminal and a feedback resistor circuit electrically connected to the voltage-dividing terminal and one of the two input terminals. The voltage-dividing resistor circuit includes a plurality of resistors that each include terminals and a switch. The plurality of resistors includes a first resistor and a second resistor. The first resistor includes a terminal that corresponds to the voltage-dividing terminal. The switch switches, from a first terminal of the first resistor to a second terminal of the second resistor, the terminal that corresponds to the voltage-dividing terminal.

In some embodiments, a method for processing an audio signal in an audio processing apparatus is disclosed. The method includes receiving an audio signal and a parameter, the parameter indicating a location of an auditory event boundary. An audio portion between consecutive auditory event boundaries constitutes an auditory event. The method further includes applying a modification to the audio signal based in part on an occurrence of the auditory event. The parameter may be generated by monitoring a characteristic of the audio signal and identifying a change in the characteristic.

In some embodiments, a method for processing an audio signal in an audio processing apparatus is disclosed. The method includes receiving an audio signal and a parameter, the parameter indicating a location of an auditory event boundary. An audio portion between consecutive auditory event boundaries constitutes an auditory event. The method further includes applying a modification to the audio signal based in part on an occurrence of the auditory event. The parameter may be generated by monitoring a characteristic of the audio signal and identifying a change in the characteristic.

An LNA having a plurality of paths, each of which can be controlled independently to achieve a gain mode. Each path includes at least an input FET and an output FET coupled in series. A gate of the output FET is controlled to set the gain of the LNA. Signals to be amplified are applied to the gate of the input FET. Additional stacked FETs are provided in series between the input FET and the output FET.

An electronic apparatus is provided. The electronic apparatus includes: a memory configured to store volume histories for a plurality of content sources; and a processor configured to, based on a content source for providing a content being changed from a first content source to a second content source, among the plurality of content sources, identify a volume level corresponding to the second content source based on a volume history of the first content source and a volume history of the second content source among the stored volume histories, and change a currently-set volume level to the identified volume level, and update the volume history of the second content source based on the changed volume level.

Methods related to amplification of radio-frequency signals. In some embodiments, a method for amplifying a radio-frequency signal can include configuring a gain stage to be in a selected one of a plurality of gain settings, with at least some of the gain settings resulting in different phases for the radio-frequency signal. The method can further include adjusting the phase of the radio-frequency signal for the selected gain setting, such that the adjusted phase is part of desired phases adjusted from the different phases.

A piecewise linear gain amplifier circuit includes a differential preamplifier and a plurality of transconductors. The differential preamplifier is electrically coupled to a differential input having an input voltage. The transconductors are electrically coupled in parallel with each other. Each transconductor includes a respective differential input that is electrically coupled to a differential output of the differential preamplifier. In addition, each transconductor includes a respective differential output that is electrically coupled to a common differential PWL output. Each transconductor has a different linear input range. An optional attenuation circuit can be electrically coupled in parallel to the differential preamplifier. The differential output of the attenuation circuit can be electrically coupled to a differential input of another transconductor, and that transconductor can have a differential output that is electrically coupled to the common differential PWL output.

Techniques for controlling one or more audio amplifiers in or associated with a device coupled on a local area network are disclosed. An example playback device includes a processor, an amplifier, a network interface, and a memory. The memory includes a software module that, when executed by the processor, causes the playback device to: operate in a first power mode in which the amplifier consumes a first amount of power; while operating in the first power mode, determine that a defined time has passed since receiving, via the network interface, a specified type of data packet; and based on determining that the defined time has passed since receiving the specified type of data packet, transition from operating in the first power mode to operate in a second power mode in which the amplifier consumes a second amount of power, wherein the first amount of power is greater than the second amount of power.

A variable gain amplifier circuit includes first and second input terminals, first and second output terminals, first and second transistors respectively having bases electrically connected to the first and second input terminals and having collectors electrically connected to the first and second output terminals, and a degeneration circuit connected between emitters of the first and second transistors. The degeneration circuit has first and second MOS transistors each having two current terminals connected in series between the emitters of the first and second transistors, series resistor circuits, first and second current sources, two resistive elements connected between the first and second current sources and gates of the first and second MOS transistors, and two resistive elements connected between the first and second current sources and two nodes of the series resistor circuits.