The IN74HC251 is identical in pinout to the LS/ALS251. The device inputs are compatible with standard CMOS utputs; with pullup resistors, they are compatible with LS/ALSTTL outputs. The device selects one of the eight binary Data Inputs, as determined by the Address Inputs. The Output Enable pin must be at a low level for the selected data to appear at the outputs. If Output Enable is high, the Y and the Y outputs are in the high impedance state. This 3-State feature allows the IN74HC251 to be used in bus-oriented systems.

• Outputs Directly Interface to CMOS, NMOS, and TTL
• Operating Voltage Range: 2.0 to 6.0 V
• Low Input Current: 1.0 µA
• High Noise Immunity Characteristic of CMOS Devices