SIGNAL TRANSMISSION CIRCUIT AND POWER CONVERSION DEVICE

摘要

The purpose of the present invention is to obtain a signal transmission circuit which outputs an external output signal that accurately reflects an external input signal. A first circuit (100) according to the present invention outputs transmission signals (VS and VR) that change between "H" and "L" in the period of an oscillation signal (CLK) in addition to transitions to "H" and "L" of an input signal (XIN). Control protection elements (23S and 23R) disable induced voltage signals (RX1 and RX2) obtained from transformers (10 and 20) in response to the transmission signals (VS and VR) during first and second mask periods. Buffer circuits (24S and 24R) and Schmitt circuits (25S and 25R) generate a signal (VS2) and a signal (VR2) that indicate "H" for a relatively long time on the basis of "H" of the induced voltage signals (RX1 and RX2). A control circuit 26 disables the signal (VS2) and the signal (VR2) when both the signals (VS2) and (VR2) indicate "H".