IN74HC251A
8-I
NPUT
D
ATA
S
ELECTOR
/M
ULTIPLEXER
WITH
3-S
TATE
O
UTPUTS
High-Performance Silicon-Gate CMOS
The IN74HC251 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
IN74HC251N Plastic
IN74HC251D SOIC
T
A
= -55° to 125° C for all
packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
A2
X
L
L
L
L
H
H
H
H
A1
X
L
L
H
H
L
L
H
H
Inputs
A0
X
L
H
L
H
L
H
L
H
OE
H
L
L
L
L
L
L
L
L
Outputs
Y
Y
Z
Z
D0
D0
D1
D1
D2
D2
D3
D3
D4
D4
D5
D5
D6
D6
D7
D7
PIN 16 =V
CC
PIN 8 = GND
D0,D1...D7=the level of the
respective D input
Z = high-impedance state
X = don’t care
1
INTEGRAL [ INTEGRAL CORP. ]
