Part Number : 74HC257
Function : Quad 2-input multiplexer; 3-state
Manufacturers : NXP Semiconductors.
The 74HC257; 74HCT257 are high-speed Si-gate CMOS devices and are pin compatible
with Low-power Schottky TTL (LSTTL). The 74HC257 and 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 74HC257 and 74HCT257 are the logic implementation of a 4-pole, 2-position switch, where the position of the switch is determined by the logic levels applied to S. The outputs are forced to a high-impedance OFF-state when OEis HIGH.
Other data sheets within the file :
74HC257D, 74HC257DB, 74HC257N, 74HC257PW