Patent ID: 8379882

Claim:
An electronic device, comprising: a capacitance electro-acoustic transducer; an audio driver, coupled to the capacitance electro-acoustic transducer, the audio driver comprising a high-voltage amplifier for receiving an input audio signal and for transforming the input audio signal into an output audio signal to drive the capacitance electro-acoustic transducer, wherein an absolute voltage value of the input audio signal is smaller than an absolute voltage value of the output audio signal; and a first low-pass filter, for receiving the input audio signal and for performing a filtering operation on the input audio signal, wherein the first low-pass filter controls a current value of the capacitance electro-acoustic transducer, based on a condition that the current value of the capacitance electro-acoustic transducer is proportional to a bandwidth of the capacitance electro-acoustic transducer, to determine the bandwidth of the capacitance electro-acoustic transducer depending on a practical application of the electronic device; wherein a bandwidth of the capacitance electro-acoustic transducer controlled by the first low-pass filter when the electronic device has a voice communication application is less than a bandwidth of the capacitance electro-acoustic transducer controlled by the first low-pass filter when the electronic device has a multimedia sound playing application.