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MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Quad 2-Input Data Selector/Multiplexer with 3-State Outputs
High–Performance Silicon–Gate CMOS
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. 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 HC257 is similar in function to the HC157 which do not have 3–state outputs.
MC74HC257 Datasheet
