摘要 |
An amplifier circuit for an electret condenser microphone includes an operational amplifier, an operational amplifier, a bias circuit, and a power supply circuit. The operational amplifier has an inverting input terminal for receiving an output of a two-wire lead electret condenser microphone and a noninverting input terminal for receiving a bias voltage. The bias circuit divides a power supply voltage to generate the bias voltage. The power supply circuit applies the power supply voltage to the electret condenser microphone through the bias circuit and a first resistor.
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