CIRCUITS AND METHODS FOR DETECTING PRESENCE OF POWERED DEVICE IN POWERED NETWORK CONNECTION

摘要

PROBLEM TO BE SOLVED: To provide circuits and methods for detecting the presence of a powered device in a powered network connection, and removing power from the powered network connection when no powered device is present.;SOLUTION: In circuits and methods of the present invention, a time-varying voltage signal is applied into an analog amplifier (140) that converts the time-varying voltage signal into a current i_DET indicative of the impedance of the network connection. The analog amplifier (140) includes a dual-output trans-conductance amplifier that provides a digital signal to indicate the removal of the powered device from the powered network connection.;COPYRIGHT: (C)2005,JPO&NCIPI