Patent ID: 7519185
Filing Date: 2009-04-14
Classification: H04R

Abstract:
1. An earphone detection device suitable for use in detecting an plug/unplug status of an earphone from an earphone driving circuit that has a detection terminal, the earphone detection device comprising: a transistor having a first terminal, a second terminal, a third terminal and a fourth terminal, wherein the first terminal and the fourth terminal are electrically connected and both electrically connected to an operating voltage; a first resistor having a first terminal and a second terminal, wherein the first terminal is electrically connected to the first terminal of the transistor and the second terminal is electrically connected to the second terminal of the transistor; a second resistor having a first terminal and a second terminal, wherein the first terminal is electrically connected to the third terminal of the transistor and the second terminal is electrically connected to a ground terminal; a capacitor having a first terminal electrically connected to the second terminal of the transistor and a second terminal electrically connected to the ground terminal; a third resistor having a first terminal and a second terminal, wherein the first terminal is electrically connected to the second terminal of the transistor and the second terminal electrically connected to the detection terminal; and a detector electrically connected to the third terminal of the transistor.