The MC74LVX157 is an advanced high speed CMOS quad 2-channel multiplexer. The inputs tolerate voltages up to 7V, allowing the interface of 5V systems to 3V systems. It consists of four 2-input digital multiplexers with common select (S) and enable (E) inputs. When E is held High, selection of data is inhibited and all the outputs go Low. The select decoding determines whether the I0n or I1n inputs get routed to the corresponding Zn outputs.