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.
Claims24
A method comprising:
- generating, by a power amplifier, an analog audio signal to an audio output as a function of a predriver signal of the power amplifier, wherein the power amplifier comprises a power supply input configured to receive a power supply voltage and the audio output is configured to couple to an electrical terminal for coupling a transducer device to the audio output;
- performing a comparison of a first signal other than the analog audio signal and indicative of the predriver signal to a second signal indicative of the power supply voltage;
- and
- determining a value of a load impedance based on the comparison.
An apparatus comprising:
- an audio circuit comprising:
- a power amplifier having an audio input configured to receive a predriver signal;
- an audio output configured to couple to an electrical terminal for coupling a transducer device to the audio circuit;
- and
- a power supply input configured to receive a power supply voltage;
- wherein the power amplifier is configured to generate an analog audio signal to the audio output as a function of the predriver signal;
- and
- a transducer load detection circuit configured to:
- perform a comparison of a first signal other than the analog audio signal and indicative of the predriver signal to a second signal indicative of the power supply voltage;
- and
- determine a value of a load impedance based on the comparison.
A method comprising:
- generating, by a power amplifier, an analog audio signal to an audio output as a function of a predriver signal of the power amplifier, wherein the power amplifier comprises a power supply input configured to receive a power supply voltage and the audio output is configured to couple to an electrical terminal for coupling a transducer device to the audio output;
- performing a comparison of a first signal indicative of a current of at least one driver device multiplied by a programmable impedance to a second signal indicative of the analog audio signal, wherein the at least one driver device receives the predriver signal;
- and
- determining a value of a load impedance based on the comparison.
An apparatus comprising:
- an audio circuit comprising:
- a power amplifier having an audio input configured to receive a predriver signal;
- an audio output configured to couple to an electrical terminal for coupling a transducer device to the audio circuit;
- and
- a power supply input configured to receive a power supply voltage;
- wherein the power amplifier is configured to generate an analog audio signal to the audio output as a function of the predriver signal;
- and
- a transducer load detection circuit configured to:
- perform a comparison of a first signal indicative of a current of at least one driver device multiplied by a programmable impedance to a second signal indicative of the analog audio signal, wherein the at least one driver device receives the predriver signal;
- and
- determine a value of a load impedance based on the comparison.
Dependencies are inferred from the claim text.