Electronic device and audio output circuit therein

摘要

An audio output circuit applied in an electronic device includes a filter capacitor and a transistor. A base of the transistor is connected to an audio processing unit, an emitter of the transistor is connected to a voltage port, a processor and an earphone detecting unit of the electronic device is electrically connected to a collector of the transistor. The filter capacitor is connected between the base of the transistor and the ground. The filter capacitor filters the audio signals generated by the audio processing unit, to ensure that and the transistor is always turned on.

主权项

1. An electronic device comprising:
an audio processing unit to generate audio signals; an audio output circuit electrically connected to the audio processing unit to output the audio signals generated by the audio processing unit; a processor electrically connected to the audio output circuit; and an earphone detecting unit electrically connected to the audio output circuit and the processor, wherein the earphone detecting unit is configured to detect whether an earphone is inserted into the electronic device; if the earphone is inserted into the electronic device, the earphone detecting unit outputs a digital-low voltage to the processor; if there is no earphone inserted into the electronic device, the earphone detecting unit outputs a digital-high voltage to the processor; the processor determines that an earphone is inserted into the electronic device when receiving a digital-low voltage, and determines that there is no earphone is inserted into the electronic device when receiving a digital-high voltage; wherein the audio output circuit comprises a transistor, and a filter capacitor; a base of the transistor is connected to the audio processing unit, an emitter of the transistor is connected to a voltage port, the processor and the earphone detecting unit is electrically connected to a collector of the transistor; a connection node is formed between the collector of the transistor, the processor, and the earphone detecting unit; the filter capacitor is connected between the base of the transistor and the ground, the filter capacitor filters the audio signals generated by the audio processing unit, to ensure that the voltage of the audio signals input into the base of the transistor is always lower than a preset value, thus to ensure the transistor is always turned on.