Detailed Description

The 74HCT257 is a high-speed Si-gate CMOS deviceand is pin compatible with low power Schottky TTL(LSTTL). The 74HCT257 have four identical 2-input multiplexers with 3-state outputs, which select 4 bits of data from two sources and are controlled by a common data select input (S). The data inputs from source 0 (1I0 to 4I0) are selected when input S is LOW and the data inputs from source 1 (1I1 to 4I1) are selected when S is HIGH. Data appears at the outputs (1Y to 4Y) in true (non-inverting) form from the selected inputs. The 74HCT257 is the logic implementation of a 4-pole,2-position switch, where the position of the switch isdetermined by the logic levels applied to S. The outputsare forced to a high impedance OFF-state when OE isHIGH.

Features:
Non-inverting data path
3-state outputs interface directly with system bus
Output capability: bus driver
ICC category: MSI

16 pin DIP. Actual brand may vary from picture.
G4867A