Input circuit, output circuit, and input/output circuit and signal transmission system using the same input/output circuit

摘要

There is provided a signal transmission system, wherein when a control signal which puts an output terminal of an output circuit 12A into a high-impedance state is supplied to the output circuit 12A and an input circuit 14A, power is fed to the input circuit 12A to operate it and, at the same time, power-feeding to the output circuit 12A is stopped; and when the control signal is not supplied to the output circuit 12A nor the input circuit 14A, power is fed to the output circuit 12A to operate it and, at the same time, power-feeding to the input circuit 12A is stopped. Also, a signal of an expected value of the output circuit 12A based on the control signal is generated from an OR circuit 45.