Patent ID: 7538589
Filing Date: 2009-05-26
Classification: H04N

Abstract:
1. An apparatus for driving a transmission line pair in response to a differential input signal, the apparatus comprising: an amplifier circuit that includes a differential input terminal and a differential output terminal, wherein the differential input terminal is coupled to a first node and a second node, and wherein the differential output terminal is coupled to the transmission line pair at a third node and a fourth node; a signal detector circuit that is coupled to the differential input terminal across the first node and the second node, wherein the signal detector circuit is arranged to assert a control signal at a first logic level when an invalid signal is identified at the differential input terminal, and wherein the signal detector circuit is arranged to assert the control signal at a second logic level when an valid signal is identified at the differential input terminal; and an offset generator circuit that is coupled to either the differential input terminal or the differential output terminal, wherein the offset generation circuit is arranged responsive to the control signal from the signal detector circuit such that the offset generation circuit is activated when the control signal is asserted at the first logic level.