Systems and methods for detection of load impedance of a transducer device coupled to an audio device
AssigneeCirrus Logic, Inc.
InventorsAnand Ilango, Daniel John Allen, Aniruddha Satoskar
Life of this patent
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Abstract
In accordance with systems and methods of the present disclosure, an audio device may include an electrical terminal, an audio circuit, and a transducer load detection circuit. The electrical terminal may couple a transducer device to the audio device. The audio circuit may generate an analog audio signal, wherein the analog audio signal is coupled to the electrical terminal The transducer load detection circuit may detect a load impedance of the transducer device when the transducer device is coupled to the audio device from characteristics measured at the electrical terminal.
Claims15
A method comprising:
- generating, by an audio circuit configured to generate analog audio signals for playback to a listener of a transducer device having a load impedance and coupled to an electrical terminal for coupling the transducer device to the audio circuit, a test analog audio signal substantially inaudible to the listener of the transducer device;
- performing a comparison of a first signal indicative of a reference current to a second signal indicative of a current delivered to the load impedance in response to the test analog audio signal to detect the load impedance;
- determining a value of the load impedance based on the comparison;
- and
- setting a capacitance of a variable compensation capacitor based on the load impedance, wherein the audio circuit further comprises a power amplifier having an audio input for receiving an audio input signal, an audio output for providing the analog audio signal, and the variable compensation capacitor.
An apparatus comprising:
- an audio circuit configured to:
- couple to an electrical terminal for coupling a transducer device having a load impedance to the audio circuit:
- generate an analog audio signal for playback to a listener of the transducer device;
- and
- generate a test analog audio signal substantially inaudible to a listener of the transducer device;
- wherein the audio circuit comprises a power amplifier having an audio input for receiving an audio input signal, an audio output for providing the analog audio signal, and a variable compensation capacitor, and a capacitance of the variable compensation capacitor is set based on the load impedance;
- and
- a transducer load detection circuit configured to:
- perform a comparison of a first signal indicative of a reference current to a second signal indicative of a current delivered to the load impedance in response to the test analog audio signal to detect the load impedance;
- and
- determine a value of the load impedance based on the comparison.
Dependencies are inferred from the claim text.