<p>The 74AHC257-Q100; 74AHCT257-Q100 is a high-speed Si-gate CMOS device and is pin compatible with Low-power Schottky TTL (LSTTL). It is specified in compliance with JEDEC standard No. 7-A.</p><p>The 74AHC257-Q100; 74AHCT257-Q100 has four identical 2-input multiplexers with 3-state outputs. They select 4 bits of data from two sources and a common data select input (S) controls them. The data inputs from source 0 (1I0 to 4I0), are selected when input S is LOW. The data inputs from source 1 (1I1 to 4I1) are selected when input S is HIGH. Data appears at the outputs (1Y to 4Y) in true (non-inverting) form from the selected inputs. The 74AHC257-Q100; 74AHCT257-Q100 is the logic implementation of a 4-pole 2-position switch. The logic levels applied to input S determine the position of the switch. The outputs are forced to a high-impedance OFF-state when OE\ is HIGH.</p><p>The logic equations for the outputs are: </p><p>1Y = OE\ x (1|1 x S + 1|0 x S)</p><p>2Y = OE\ x (2|1 x S + 2|0 x S)</p><p>3Y = OE\ x (3|1 x S + 3|0 x S)</p><p>4Y = OE\ x (4|1 x S + 4|0 x S)</p><p> This product has been qualified to the Automotive Electronics Council (AEC) standard Q100 (Grade 1) and is suitable for use in automotive applications.</p></p>