The LVXT8051 is similar in pinout to the high-speed HC4051A and the metal-gate MC14051B. The Channel-Select inputs determine which one of the Analog Inputs/Outputs is to be connected by means of an analog switch to the Common Output/Input. When the Enable pin is HIGH, all analog switches are turned off. The Channel-Select and Enable inputs are compatible with TTL-type input thresholds. The input protection circuitry on this device allows overvoltage tolerance on the input, allowing the device to be used as a logic-level translator from 3.0 V CMOS logic to 5.0V CMOS Logic or from 1.8V CMOS logic to 3.0 V CMOS Logic while operating at the higher-voltage power supply. The MC74LVXT8051 input structure provides protection when voltages up to 7.0 V are applied, regardless of the supply voltage. This allows the MC74LVXT8051 to be used to interface 5.0 V circuits to 3.0 V circuits.