Patent ID: 8040813

Claim:
A communication apparatus for handling a signal, comprising: a common signal node including a first conductor operable to conduct a first signal; a first circuit coupled to said common signal node, operable to receive said first signal; and a signal-handling element coupled to said first conductor, having an isolating circuit coupled to said first conductor, a second conductor operable to conduct an output of said isolating circuit, and a signal-handling circuit coupled to said second conductor, said signal-handling circuit operable to perform a signal-handling function in response to said output of said isolating circuit, wherein said isolating circuit is operable to isolate said common signal node and said first circuit from said second conductor and said signal-handling circuit, wherein said first signal includes a first communication signal and said first circuit is operable to perform first analog signal processing of said first communication signal including analog amplification of said first communication signal, wherein said common signal node includes a pair of said first conductors, said second conductor includes a pair of said second conductors, said first communication signal includes a differential communication signal conducted by said pair of first conductors, and said signal-handling element includes a signal detector, said isolating circuit includes a front stage receiver element of said signal detector operable to regenerate said differential communication signal as a pair of regenerated signals on said pair of second conductors, and said signal-handling circuit of said signal detector includes circuitry operable to produce time-averaged signals from said regenerated signals, said signal-handling circuit being operable in response to said time-averaged signals to detect presence or absence of said first communication signal.