Circuit apparatus and method for detecting earphone in portable terminal

Abstract

A circuit apparatus and a method for detecting an earphone in a portable terminal are provided. The apparatus includes an earjack, a first switch, a second switch, a comparator, and a main chip. The earjack outputs a signal informing whether an earphone is inserted, provides a signal input from a third pole of the inserted earphone to the first switch, and provides a signal input from a fourth pole to the second switch. The first switch outputs a signal provided from the earjack to one of a comparator and a ground depending on an input control signal. The second switch outputs a signal provided from the earjack to one of the comparator and the ground depending on the input control signal. The comparator compares a voltage of a signal provided from one of the first switch and the second switch with a reference voltage to output a signal representing a comparison result. The main chip outputs the control signal depending on the signal informing whether the earphone is inserted, and one of changes and maintains the control signal depending on an output signal of the comparator.

Dependencies are inferred from the claim text.