HD74LS251
1 of 8 Data Selector / Multiplexer
(with strobe and three-state outputs)
REJ03D0467–0300
Rev.3.00
Jul.15.2005
This data selector / multiplexer contains full on-chip binary decoding to select one-of-eight data sources and features a
strobe-controlled 3-state output.
The strobe must be at a low logic level to enable this device. The 3-state outputs permit a number of outputs to be
connected to a common bus.
When the strobe input is high, both outputs are in a high-impedance state in which both the upper and lower transistors
of each totem-pole output are off, and the output neither drives nor loads the bus significantly. When the strobe is low,
the outputs are activated and operate as standard TTL totem-pole outputs.
To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels, the output
control circuitry is designed so that the average output disable time is shorter than the average output enable time.
Features
•
Ordering Information
Part Name
HD74LS251P
HD74LS251FPEL
Package Type
DILP-16 pin
SOP-16 pin (JEITA)
Package Code
(Previous Code)
PRDP0016AE-B
(DP-16FV)
PRSP0016DH-B
(FP-16DAV)
Package
Abbreviation
P
FP
Taping Abbreviation
(Quantity)
—
EL (2,000 pcs/reel)
Note: Please consult the sales office for the above package availability.
Pin Arrangement
3
2
Data Inputs
1
0
Y
Outputs
W
Strobe
GND
1
D
3
2
3
4
5
6
7
8
D
2
D
1
D
0
Y
W
S
C
D
4
D
5
D
6
D
7
A
B
16
15
14
13
12
11
10
9
V
CC
4
5
Data Inputs
6
7
A
B
C
Data Select
(Top view)
Rev.3.00, Jul.15.2005, page 1 of 5
RENESAS [ RENESAS TECHNOLOGY CORP ]
