a signal transmission circuit , which is capable of improving dc characteristics , delay characteristics , and linearity in a voltage region and maintaining tolerant functions , is provided . the signal transmission circuit includes a first transmission circuit , a second transmission circuit , an inverting circuit , a first switching circuit , and a second switching circuit . the first transmission circuit transmits a signal of a first node to a second node , and the second transmission circuit transmits the signal of the first node to the second node . the inverting circuit inverts the signal of the second node , and the first switching circuit pulls down a third node in response to an output signal of the inverting circuit . the second switching circuit transmits the signal of the first node to the third node , and the second transmission circuit is controlled in response to the signal of the third node . preferably , a second supply voltage is generated in a voltage generation circuit , a first supply voltage is greater than the second supply voltage , the inverting circuit is a schmitt trigger , and the signal transmission circuit is a tolerant input buffer .