| 摘要 |
<p>Provided are an identification device for matching an audio interface of a mobile terminal and an electronic signature tool. The audio interface of a mobile terminal comprises a first pin, a second pin and a third pin. The first pin is one of a microphone pin and a ground pin; the second pin is the other one of the microphone pin and the ground pin; and the third pin is one of a single-channel audio output pin and a multichannel audio output pin, wherein the third pin is connected to the first pin and the second pin through a switch module. When the switch module connects the third pin to the first pin to form a loop, the impedance value of the loop matches the identification resistance of the mobile terminal; and when the switch module connects the third pin to the second pin to form a loop, the impedance value of the loop matches the identification resistance of the mobile terminal. Therefore the impedance of the loop between the audio output pin of the audio interface and the ground pin matches the identification resistance of the mobile terminal, thereby ensuring that an inserted device passes the detection of the mobile terminal.</p> |
