SL74HC251
8-Input Data Selector/Multiplexer with 3-State Outputs
High-Performance Silicon-Gate CMOS
The SL74HC251 is identical in pinout to the LS/ALS251. The device
inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LS/ALSTTL outputs.
The device selects one of the eight binary Data Inputs, as
determined by the Address Inputs. The Output Enable pin must be at a
low level for the selected data to appear at the outputs. If Output
Enable is high, the Y and the Y outputs are in the high-impedance state.
This 3-State feature allows the IN74HC251 to be used in bus-oriented
systems.
•
Outputs Directly Interface to CMOS, NMOS, and TTL
•
Operating Voltage Range: 2.0 to 6.0 V
•
Low Input Current: 1.0
µA
•
High Noise Immunity Characteristic of CMOS Devices
ORDERING INFORMATION
SL74HC251N Plastic
SL74HC251D SOIC
T
A
= -55° to 125° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Inputs
A2
X
L
L
L
L
PIN 16 =V
CC
PIN 8 = GND
H
H
H
H
A1
X
L
L
H
H
L
L
H
H
A0
X
L
H
L
H
L
H
L
H
OE
H
L
L
L
L
L
L
L
L
Outputs
Y
Z
D0
D1
D2
D3
D4
D5
D6
D7
Y
Z
D0
D1
D2
D3
D4
D5
D6
D7
D0,D1...D7=the level of the respective D
input
Z = high-impedance state
X = don’t care
SLS
System Logic
Semiconductor
SLS [ SYSTEM LOGIC SEMICONDUCTOR ]
