| 摘要 |
A control circuit and method for an audio amplifier detect a signal for driving a speaker to control the switching frequency and the operation mode of a charge pump in the audio amplifier, to improve power efficiency of the audio amplifier. Preferably, a digital interface is further used to test the magnitude of the output signal of the audio amplifier, to reduce the costs of analog test. The charge pump has fewer switches and thus saves costs and die area of an integrated circuit. The control method needs only two phase control for the charge pump to generate a positive voltage and a negative voltage, and thus simplifies the operation of the circuit.
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