Patent ID: 7834638

Claim:
A differential transmission circuit comprising: a signal output circuit connected to one end of a transmission path for sending a high-speed differential signal and a pulse wave; a signal input circuit connected to the other end of the transmission path for receiving the high-speed differential signal and the pulse wave, wherein a terminating resistor is included; a bias controller for controlling a bias voltage on the transmission path; a bias sensing circuit for sensing an existence of the bias voltage; a terminating resistance controller for disconnecting the terminating resistor when the bias sensing circuit senses the bias voltage, connecting the terminating resistor when the bias sensing circuit does not sense the bias voltage; a sensing input circuit for sensing the pulse wave reflected at the signal input circuit; and an output setting controller for setting an electric characteristic of a signal outputted from the signal output circuit according to a propagation time which is a period from a time at which the signal output circuit sends the pulse wave to a time at which the sensing input circuit receives the reflected pulse wave.