Skyworks Solutions, Inc.

Avnera Corpor Ation

Deepika Kumari

Amit Kumar

Mark R Peting

Wai Laing Lee

Colin Doolittle

Evan Michael Albright

David Lamb

Spencer David Leuenberger

In some embodiments, an audio driver includes an audio amplifier configured to operate in a high output resistance (HOR) mode with an HOR driver or a zero output resistance (ZOR) mode with a ZOR driver, The audio amplifier includes an output node coupled to both of the HOR driver and the ZOR driver, such that the output node is subject to an effect of the ZOR driver in a disabled state when the audio amplifier is operating in the HOR mode. The audio driver further includes a control system configured to correct for the effect of the disabled ZOR driver by adjusting an input signal.

Output capacitance distortion correction for audio amplifiers

In some embodiments, a calibration circuit for an audio amplification system can include a tone generator configured to provide a tone having a frequency to an input path of an audio amplifier, such that an input signal provided to the audio amplifier includes the tone, a a first sampling circuit configured to sample an output signal at an output node of the audio amplifier, and a second sampling circuit configured to sample the input signal at an input node of the audio amplifier. The calibration circuit can further include a gain adjustment circuit configured to generate a correction signal based on the sampled output signal and the sampled input signal to correct for a gain variation of the audio amplifier.

Gain calibration for audio amplifiers

Disclosed is a signal processor for headphone off-ear detection. The signal processor includes an audio output to transmit an audio signal toward a headphone speaker in a headphone cup. The signal processor also includes a feedback (FB) microphone input to receive a FB signal from a FB microphone in the headphone cup. The signal processor also includes an off-ear detection (OED) signal processor to determine an audio frequency response of the FB signal over an OED frame as a received frequency response. The OED processor also determines an audio frequency response of the audio signal times an off-ear transfer function between the headphone speaker and the FB microphone as an ideal off-ear response. A difference metric is generated comparing the received frequency response to the ideal off-ear frequency response. The difference metric is employed to detect when the headphone cup is disengaged from an ear.

Headphone off-ear detection

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Portland, OR, United States of America

Deepika Kumari