A variable gain low noise amplifier (LNA) and a method for controlling a gain of the variable gain LNA are provided. The variable gain LNA may include a first transistor, a first degeneration inductor, a second transistor and a second degeneration inductor, wherein the first degeneration inductor is coupled to a source terminal of the first transistor, and the second degeneration inductor is coupled to a source terminal of the second transistor. Gate terminals of the first transistor and the second transistor are configured to receive an input signal. The first transistor and the first degeneration inductor belong to a first branch of the variable gain LNA, and the second transistor and the second degeneration inductor belong to a second branch of the variable gain LNA. More particularly, a gain of the variable gain LNA is determined by controlling whether to turn off the second branch.

An example playback device includes a first interface for receiving a first audio signal from a first audio source; a second interface for receiving a second audio signal from a second audio source; and a processor configured to: cause the playback device to playback the second audio signal; determine that the first audio signal is present at the first interface; in response to determining that the first audio signal is present at the first interface, (i) cease playback of the second audio signal being played by the playback device and (ii) cause the playback device to playback the first audio signal; receive an instruction to stop the playback device from playing the first audio signal while the first audio signal is still present at the first interface; and arm the playback device such that a subsequent presence of the first audio signal at the first interface causes the playback device to play the first audio signal.

A multiple aperture ultrasound imaging system may be configured to store raw, un-beamformed echo data. Stored echo data may be retrieved and re-beamformed using modified parameters in order to enhance the image or to reveal information that was not visible or not discernible in an original image. Raw echo data may also be transmitted over a network and beamformed by a remote device that is not physically proximate to the probe performing imaging. Such systems may allow physicians or other practitioners to manipulate echo data as though they were imaging the patient directly, even without the patient being present. Many unique diagnostic opportunities are made possible by such systems and methods.

In an embodiment, a class-D amplifier includes an input terminal configured to receive an input signal; a comparator having an input coupled to the input terminal; a deglitching circuit having an input coupled to an output of the comparator; and a driving circuit having an input coupled to an output of the deglitching circuit. The deglitching circuit includes a logic circuit coupled between the input of the deglitching circuit and the output of the deglitching circuit. The logic circuit is configured to receive a clock signal having the same frequency as the switching frequency of the class-D amplifier.

In one example, a zone player may include a network interface, at least one processor, a non-transitory computer-readable medium, and program instructions stored on the non-transitory computer-readable medium that may be executable by the at least one processor such that the zone player is configured to receive an instruction to change a volume setting of the zone player to a requested volume level; in response to receiving the instruction to change the volume setting of the zone player to the requested volume level, adjust the volume setting of the zone player to an adapted volume level that is lower than the requested volume level; and after adjusting the volume setting of the zone player to the adapted volume level, send an indication that the volume setting of the zone player has been adjusted to the requested volume level rather than the adapted volume level.

An example first playback device includes programming to perform functions including: (1) storing an active volume state variable in memory, wherein the active volume state variable corresponds to a current playback volume; (2) storing a volume limit state variable in memory, wherein the volume limit state variable corresponds to a playback volume limit of the first playback device; (3) detecting a command to begin playback of media at a proposed playback volume different from the current playback volume; (4) based on comparing (i) the playback volume limit and (ii) the proposed playback volume, selecting a startup playback volume; (5) playing back media at the startup playback volume; and (6) causing at least a second playback device of the media playback system to play back media at the startup playback volume.

An electronic device may comprise audio processing circuitry and a universal serial bus (USB) connector having a first contact and a second contact. In a first mode of operation, the audio processing circuitry is configured to output one or more audio signals carrying music and/or voice via the first contact and the second contact. In a second mode of operation, the audio processing circuitry is configured to output a signal for delivering supply current via the first contact and the second contact. While the electronic device is in the first mode of operation, a gain and/or volume limit of the audio processing circuitry may be set to a first level, and while the electronic device is in the second mode of operation, the gain and/or volume limit of the audio processing circuitry may be set to a second level that is higher than the first level.

In an embodiment, an amplifier circuit includes a second stage that includes a first switch circuit including first and second terminals, a plurality of resistive elements coupled between the first and second terminals of the first switch circuit, and a plurality of switches configured to control an equivalent resistance between the first and second terminals of the first switch circuit. During play mode, the second stage has a gain between the input of the second stage and the output of the second stage of a first value. During a transition from mute mode to play mode, the amplifier circuit is configured to progressively increase the gain of the second stage from a second value to the first value. During a transition from play mode to mute mode, the amplifier circuit is configured to progressively decrease the gain of the second stage from the first value to the second value.

An apparatus includes a controller that controls operation of an amplifier. The amplifier receives a sample voltage produced by a resistive path; the sample voltage from the resistive path is indicative of a magnitude of current through a motor winding. The controller selects a gain setting to apply to the amplifier based on one or more conditions. The selected gain setting is selected amongst multiple possible gain settings. Subsequent to selection, via application of the selected gain setting to the amplifier, and based on an output of the amplifier, the controller monitors a magnitude of the current through the motor winding. According to one configuration, the amplifier adjusts the magnitude of the selected gain setting depending on one or more parameters such as the magnitude of the current through the motor winding, a selected operational range of controlling current through the motor winding, etc.

Systems and methods for a playback device outputting an audio alert from a network-enabled device include (i) while the playback device is playing back audio content, receiving an alert communication from the network-enabled device, the alert communication including (a) an audio notification identifier that identifies an audio notification and (b) a priority identifier that identifies a priority level of the audio notification; (ii) responsive to receiving the alert communication, adding the audio notification to a notification queue at a particular queue position, where the particular queue position of the audio notification in the notification queue is based on the priority level of the audio notification relative to other audio content in the notification queue; (iii) adjusting playback of the audio content for playing back the audio notification; and (iv) the playback device playing back the audio notification.