| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmission drive circuit which can reduce distortion of a transmitted signal and transmission noise, and which can be separated from signal wiring.SOLUTION: A transmission drive circuit 700 includes: a drive transistor 10 and an isolation diode 31 which are connected between a node n1 coupled to signal wiring SL commonly used by transmission of a transmitted signal and transmission of a received signal, and power supply wiring HVM; an isolation diode 32 and a drive transistor 20 which are connected between the node n1 and voltage wiring HVM; a switch 41 connected between a node n2 between the drive transistor 10 and the isolation diode 31, and a node n4 of ground voltage Vs; and a switch 43 connected between a node 3 between the drive transistor 20 and the isolation diode 32, and the node 4, in which the switches 41, 42 are turned to an OFF state by a clamp switch control circuit 200 so as to pass a bias current when a transmitted signal is transmitted through the signal wiring SL.SELECTED DRAWING: Figure 1 |
