A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal. A preferred embodiment of the RF transceiver IC includes two distinct PA circuits, two distinct receive signal amplifier circuits, and a four-way antenna switch to selectably couple a single antenna connection to any one of the four circuits.

A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal. A preferred embodiment of the RF transceiver IC includes two distinct PA circuits, two distinct receive signal amplifier circuits, and a four-way antenna switch to selectably couple a single antenna connection to any one of the four circuits.

The invention provides a concept for combined dynamic range compression and guided clipping prevention for audio devices. An audio decoder for decoding an audio bitstream and a metadata bitstream related to the audio bitstream according to the concept includes an audio processing chain including a plurality of adjustment stages including a dynamic range control stage for adjusting a dynamic range of the audio output signal and a guided clipping prevention stage for preventing clipping of the audio output signal; and a metadata decoder configured to receive the metadata bitstream and to extract dynamic range control gain sequences and guided clipping prevention gain sequences from the metadata bitstream, at least a part of the dynamic range control gain sequences being supplied to the dynamic range control stage, and at least a part of the guided clipping prevention gain sequences being supplied to the guided clipping prevention stage.

Example embodiments provide a process that includes one or more of receiving an audio signal at a feedback compressor circuit, multiplying the received audio signal with a power feedback signal to create a product audio signal, wherein the feedback signal comprises a low-pass filtered signal, applying a power amplifier to the product audio signal, and providing the amplified product audio signal as an output signal to a speaker.

A digital signal processing method for ambient sound acoustic dosimetry. Strength of a microphone signal generated by a watch worn by a user is determined and converted into a sound sample having units for sound noise exposure. This is repeated multiple times to produce a time sequence of sound samples that is written to a secure database access to which is authorized by the user. Other aspects are also described and claimed.

Example embodiments provide a process that includes one or more of receiving an audio signal from a feedback path of a feedback compressor circuit, determining whether an auxiliary attenuation value applied to the feedback compressor circuit has changed since a last audio signal was received, responsive to determining the auxiliary value has changed, determining a current operational state value of the LPF needs to be modified based on the changed auxiliary attenuation value, modifying the operational state value of the LPF, and applying the audio signal to the modified LPF.

Example embodiments provide a process that includes one or more of receiving an audio signal from a feedback path of a feedback compressor circuit, determining whether an auxiliary attenuation value applied to the feedback compressor circuit has changed since a last audio signal was received, responsive to determining the auxiliary value has changed, determining a current operational state value of the LPF needs to be modified based on the changed auxiliary attenuation value, modifying the operational state value of the LPF, and applying the audio signal to the modified LPF.

In-ear sound pressure level, SPL, is determined that is caused by output audio being converted into sound by a headset worn by a user. The in-ear SPL is converted into a sound sample having units that are suitable for evaluating sound noise exposure. These operations are repeated to produce a sequence of sound samples during playback. This sequence of sound samples is then written to a secure database. Access to the database is authorized by the user. Other aspects are also described and claimed.

Systems and methods for limiting volume in an audio playback device using a feedback controller are disclosed herein. In one example, a gain stage modulates gain of an audio signal based in part on feedback from a downstream limiter. The gain stage receives a first audio signal as well as a feedback signal from the feedback controller. Based at least in part on the feedback signal from the feedback controller, the gain stage modulates a gain of the first audio signal to provide a second audio signal. The second audio signal is delivered to the limiter, which limits the second audio signal to produce an output signal. The output signal is played back via a transducer. The feedback controller receives a gain reduction value from the limiter and determines a feedback signal to provide to the gain stage upstream of the limiter.

Systems and methods for limiting volume in an audio playback device using a feedback controller are disclosed herein. In one example, a gain stage modulates gain of an audio signal based in part on feedback from a downstream limiter. The gain stage receives a first audio signal as well as a feedback signal from the feedback controller. Based at least in part on the feedback signal from the feedback controller, the gain stage modulates a gain of the first audio signal to provide a second audio signal. The second audio signal is delivered to the limiter, which limits the second audio signal to produce an output signal. The output signal is played back via a transducer. The feedback controller receives a gain reduction value from the limiter and determines a feedback signal to provide to the gain stage upstream of the limiter.