Patent ID: 9357285
Filing Date: 2016-05-31
CPC Classification: H04R

Claim Text:
1. An earphone detecting circuit for a portable electronic device comprising an earphone jack and a microcontroller, the earphone detecting circuit comprising: a signal input terminal connected to the earphone jack; a voltage dividing circuit connected to the signal input terminal; a detecting circuit connected to the voltage dividing circuit; and a signal output terminal connected between the detecting circuit and the microcontroller; wherein the detecting circuit comprises a transistor, a resistor, and a first capacitor, a gate of the transistor is connected to the signal input terminal through the voltage dividing circuit; a drain of the transistor is grounded; a source of the transistor is connected to a power supply through the resistor; one end of the first capacitor is connected between the power supply and the resistor of the detecting circuit, another end of the first capacitor is grounded; the signal output terminal is electronically connected between the resistor and the source of the transistor, when the portable electronic device is receiving a call, the signal input terminal receives a signal and transmits the received signal to the detecting circuit through the voltage dividing circuit, the detecting circuit controls the signal transmitted to the signal output terminal to be a constant signal.