Patent ID: 9036666
Filing Date: 2015-05-19
Classification: H04J,H04L,H04N

Abstract:
1. An interface circuit comprising: a first transmitter unit, including an amplifier unit, configured to transmit a first differential signal to an external device through a transmission line; a second transmitter unit, including an adder unit, configured to transmit a common-mode signal to the external device, wherein the common-mode signal is multiplexed to the transmission line, the adder unit including first and second adders configured to receive the first differential signal from the amplifier unit and output the common-mode signal, the first adder being configured to receive a first signal of the first differential signal from the first transmitter unit and the second adder being configured to receive a second signal of the first differential signal from the first transmitter unit, the second signal being inverted relative to the first signal; a receiver unit configured to receive a third differential signal, wherein the third differential signal is a combination of the first differential signal and a second differential signal, wherein the second differential signal is received by the receiver unit from the external device; and a communication circuit that communicates with the external device via a pair of differential transmission lines included in the transmission line, the pair of differential transmission lines including a hot plug detect line, wherein the communication circuit includes a circuit for biasing the transmission line to a first voltage level to indicate that the device is connected to the transmission line, thereby notifying the external device of a connection status of its own device by at least one of direct current bias potentials of the pair of differential transmission lines; wherein the transmission line is used for bidirectional communication.