The MC74HC257N is identical in pinout to the LS257. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs. This device selects a (4?bit) nibble from either the A or B inputs as determined by the Select input. The nibble is presented at the outputs in noninverted form when the Output Enable pin is at a low level. A high level on the Output Enable pin switches the outputs into the high?impedance state. The MC74HC257N is similar in function to the HC157 which do not have 3?state outputs.Features:Output Drive Capability: 15 LSTTL LoadsOutputs Directly Interface to CMOS, NMOS, and TTLOperating Voltage Range: 2 to 6 VLow Input Current: 1 mAHigh Noise Immunity Characteristic of CMOS Devices16 pin DIP. Manufactured by Motorola.A10872
