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 audio signal processing device comprises: a receiver for receiving an input audio signal; a processor for generating loudness metadata corresponding to the input audio signal; and an outputter for transmitting the loudness metadata generated by the processor. The processor is configured to acquire loudness information analyzed from input content, acquires loudness information about the input audio signal by measuring the loudness of the input audio signal, generates the loudness metadata by converting the loudness information, and transmits, through the outputter, the generated loudness metadata to an output device for outputting the input audio signal.

An automatic gain control system for a receiver for an asymmetrical and/or unbalanced constellation, the system including: an automatic gain control loop adapted to be coupled to both a first transimpedance amplifier coupled to a first analog-to-digital converter forming a first tributary and a second transimpedance amplifier coupled to a second analog-to-digital converter forming a second tributary; wherein the automatic gain control loop is operable for providing an offset gain control voltage to gain balance a transimpedance amplifier voltage and a power associated with the first tributary and a transimpedance amplifier voltage and a power associated with the second tributary. The automatic gain control loop includes an analog automatic gain control loop. The automatic gain control loop is implemented in hardware or firmware.

Methods and systems are described that include a differential amplifier driving an active load circuit, the active load circuit having a pair of load transistors and a high-frequency gain stage providing high frequency peaking for the active load circuit according to a frequency response characteristic determined in part by resistive values of a pair of active resistors connected, respectively, to gates of the pair of load transistors, and a bias circuit configured to stabilize the high frequency peaking of the high-frequency gain stage by generating a process-and-temperature variation (PVT)-dependent control voltage at gates of the active resistors to stabilize the resistive values of the pair of active resistors to account for PVT-dependent voltages at the gates of the pair of load transistors.

In described examples, a method of processing an audio program material includes converting the audio program material into a frequency domain audio program material; increasing or decreasing an energy amplitude of one or more energy troughs in an audio data sample in the frequency domain audio program material, ones of the energy troughs being located between respective ones of one or more pairs of adjacent energy peaks in the audio data sample, the pairs of adjacent energy peaks selected to correspond to frequencies of sounds which were captured to create the audio program material; repeating the increasing or decreasing step for multiple audio data samples in the frequency domain audio program material; and converting the frequency domain audio program material into a time domain audio program material.

Embodiments are described herein that provide a dedicated command device that is bonded to a zone player or zone to perform adjustments to the zone player or zone. In an example implementation, a command device receives an instruction to pair with a first playback device that is associated with a group of playback devices that includes the first playback device and at least one additional playback device. The group of playback devices is associated with at least one group variable controlling playback by the playback devices of the group. The command device receives an input to adjust a first group variable of the at least one group variable and transmits, via a wireless communications interface, a command that causes an adjustment of the first group variable for the group of playback devices.

Exemplary multipath digital microphones described herein can comprise exemplary embodiments of automatic gain control and multipath digital audio signal digital signal processing chains, which allow low power and die size to be achieved as described herein, while still providing a high DR digital microphone systems. Further non-limiting embodiments can facilitate switching between multipath digital audio signal digital signal processing chains while minimizing audible artifacts associated with either the change in the gain automatic gain control amplifiers switching between multipath digital audio signal digital signal processing chains.

Many portable playback devices cannot decode and playback encoded audio content having wide bandwidth and wide dynamic range with consistent loudness and intelligibility unless the encoded audio content has been prepared specially for these devices. This problem can be overcome by including with the encoded content some metadata that specifies a suitable dynamic range compression profile by either absolute values or differential values relative to another known compression profile. A playback device may also adaptively apply gain and limiting to the playback audio. Implementations in encoders, in transcoders and in decoders are disclosed.

Embodiments described herein provide for smart configuration of audio settings for a playback device. According to an embodiment, while a playback device is a part of a first zone group that includes the playback device and at least one first playback device, the playback device applies a first audio setting. The embodiment also includes the playback device joining a second zone group that includes the playback device and at least one second playback device. The embodiment further includes the playback device applying a second audio setting based on an audio content profile corresponding to the second zone group.

This application relates to audio circuits, such as audio driving circuits, with improved audio performance. An audio arrangement (200) has an audio circuit (201) with a forward signal path between an input (102) for an input digital audio signal (D.sub.IN) and an output (103) for an output analogue audio signal (A.sub.OUT). The circuit also has a feedback path comprising an analogue-to-digital conversion module (202) for receiving an analogue feedback signal (V.sub.FB) derived from the output analogue audio signal and outputting a corresponding digital feedback signal (D.sub.FB). The analogue-to-digital conversion module (202) has an ADC (108), an analogue gain element (203) configured to apply analogue gain (G.sub.A) to the analogue feedback signal before the ADC and a digital gain element (204) for applying digital gain (G.sub.D) to a signal output from the ADC. A gain controller (205) controls the analogue gain and the digital gain applied based on the input digital audio signal (D.sub.IN).