Speaker Failure Detection Circuit Using Temperature-Adjusted Peak Frequency
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Solution Overview
Problem
Existing speaker failure notification devices struggle to accurately determine speaker failure due to impedance changes caused by temperature variations, leading to potential misclassification of speaker failure.
Innovation Solution
A semiconductor device with a modulation circuit, test signal generation circuit, amplification circuit, peak frequency detection circuit, and determination circuit that modulates a test signal to detect the peak frequency of the sound reproduction device's impedance, taking into account temperature information to accurately determine speaker failure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If impedance measurement is used to determine speaker failure, then failure detection capability is improved, but measurement accuracy deteriorates due to temperature-induced impedance changes
Solution Approach 1:
The patent changes the measurement parameter from direct impedance value to peak frequency of impedance. By measuring the frequency at which impedance reaches its peak rather than the absolute impedance value, the system achieves temperature-insensitive failure detection, as the peak frequency remains relatively stable across temperature variations while absolute impedance values fluctuate significantly.
2Ease of operation
If fixed reference impedance range is used for failure determination, then determination simplicity is improved, but determination accuracy deteriorates due to temperature variations
Solution Approach 1:
The patent makes the reference frequency range dynamic by adjusting it according to temperature information. The determination circuit modifies the reference range based on detected temperature, allowing accurate failure determination across varying temperature conditions while maintaining automated operation without requiring manual calibration for each temperature point.
Data Source
AI summary
A semiconductor device includes: a test signal generation circuit that, modulates a test signal to generate third and fourth modulated signals; an amplification circuit that, outputs a third amplified signal obtained by amplifying the third modulated signal to a first output terminal and outputs a fourth amplified signal obtained by amplifying the fourth modulated signal to a second output terminal; a peak frequency detection circuit that, measures a potential difference between the first and second output terminals to detect a peak frequency at which an impedance of a sound reproduction device reaches a peak; and a determination circuit that, determines whether or not the peak frequency is included in a reference frequency range determined based on a frequency band of the test signal and temperature information of the sound reproduction device.