Synaptics Incorporated
Non-linear feedback control for temperature and power protection of loudspeakers

Abstract:

A system and a method provide for protecting a loudspeaker from thermal and/or mechanical failure by monitoring for over-temperature and over-power conditions. The system generates a first gain from a first speaker protection controller in response to a driving voltage and/or a driving current of a loudspeaker, and generates a second gain from a second speaker protection controller in response to the driving voltage and/or a driving current of the loudspeaker, if the temperature exceeds a thermal limit or if the power exceeds a maximum power. The system applies the second gain to an audio signal to lower the audio signal if the first speaker protection controller fails.