Patent ID: 8693151

Claim:
A differential transmission circuit, comprising: a first ESD protection element connected between a first transmission line and a ground; a second ESD protection element connected between a second transmission line and the ground; wherein the first and the second ESD protection element route a part of a current to the ground; a common mode filter that includes a first inductor element and a second inductor element which are magnetically coupled to each other, wherein the first inductor element is connected in series between the first transmission and a third transmission line and the second inductor element is connected in series between the second transmission line and a fourth transmission line; a first ESD protection diode of which a cathode is directly connected to the third transmission line and of which an anode is connected to the ground; a second ESD protection diode of which a cathode is directly connected to the fourth transmission line and of which an anode is connected to the ground; a first physical resistor which is connected in series between the third transmission line and a fifth transmission line; and a second physical resistor which is connected in series between the fourth transmission line and a sixth transmission line, wherein the first ESD protection diode and the second ESD protection diode bypass another part of the current to the ground; and wherein resistance values of the first and second resistors are set to 10 to 15 ohms, respectively, electrostatic capacitance values of the first and second ESD protection elements are less than 0.3 pF, respectively, and a clip voltage of each of the first and second ESD protection diodes is set to a value less than 10 V.