View mc74hc257 datasheet:

MOTOROLA SEMICONDUCTOR TECHNICAL DATA MC74HC257 Quad 2-Input Data Selector/Multiplexer with 3-State Outputs N SUFFIX PLASTIC PACKAGE 16 High–Performance Silicon–Gate CMOS CASE 648–08 1 The MC74HC257 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. D SUFFIX This device selects a (4–bit) nibble from either the A or B inputs as 16 SOIC PACKAGE determined by the Select input. The nibble is presented at the outputs in CASE 751B–05 1 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. ORDERING INFORMATION The HC257 is similar in function to the HC157 which do not