SIGNAL TRANSMISSION CIRCUIT

摘要

PROBLEM TO BE SOLVED: To reduce the unnecessary radiation of electromagnetic waves in a signal transmitting circuit. SOLUTION: A data outputting circuit 101 of a transmission side circuit and a data inputting part 130 of a reception side circuit are connected through a transmission line 103. An output transistor 105 of the data outputting part 101 is formed as an open drain type structure. The data inputting part 130 is provided with a constant current source 107, an amplitude control unit 109 for controlling the voltage of the transmission path to be present within an almost fixed range, a current mirror 140 including source side and load side transistors 110 and 111, an output node N2 connected to an internal circuit 114 of the reception side circuit, and a load 112 for converting the current output of the load side transistor 111 of the current mirror 140 into a voltage. The voltage amplitude of the transmission line 103 is suppressed so that the unnecessary radiation of the electromagnetic waves can be reduced.