Patent ID: 7340284

Claim:
A device for a mobile phone to connect to an ear-microphone, the mobile phone including a codec which has hands-free-kit audio transmission and reception terminals, the device comprising: an interface connector connecting the mobile phone to the ear microphone, the interface connector having at least four terminals which include an RX-A terminal for audio reception, a TX-A terminal for audio transmission, a GND terminal for ground, and an INT terminal for interrupt detection, the TX-A and RX-A terminals connected respectively to the hands-free-kit audio transmission and reception terminals; a controller including first and second interrupt terminals, the first interrupt terminal used for detecting whether the ear-microphone is connected to the mobile phone, the second interrupt terminal used for detecting whether a call connection/termination key of the ear-microphone is activated; a first voltage drop detector detecting a first voltage drop when the ear-microphone is connected through the interface connector, and outputting a first interrupt signal to the first interrupt terminal; and a second voltage drop detector detecting a second voltage drop when a call connection/termination key is activated with the ear-microphone being connected to the mobile phone, and outputting a second interrupt signal to the second interrupt terminals, wherein the INT terminal is connected to the first and second voltage drop detectors.