SDFS066A − MARCH 1987 − REVISED OCTOBER 1993
Copyright 1993, Texas Instruments Incorporated
2−1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443
•3-State Versions of SN54F151B and
SN74F151B
•3-State Outputs Interface Directly With
System Bus
•Performs Parallel-to-Serial Conversion
•Complementary Outputs Provide True and
Inverted Data
•Package Options Include Plastic
Small-Outline Packages, Ceramic Chip
Carriers, and Standard Plastic and Ceramic
300-mil DIPs
description
These data selectors/multiplexers contain full
binary decoding to select one of eight data
sources and feature strobe-controlled
complementary outputs. The 3-state outputs can
interface with and drive data lines of bus-
organized systems. When the strobe (G) 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.
The SN54F251B is characterized for operation
over the full military temperature range of −55°C
to 125°C. The SN74F251B is characterized for
operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
SELECT
C B A
GY W
X X X H Z Z
LLL L D0 D0
LLH L D1 D1
LHL L D2 D2
LHH L D3 D3
HLL L D4 D4
HLH L D5 D5
HHL L D6 D6
H H H L D7 D7
D0, D1, . . . D7 = the level of the respective D input.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
D3
D2
D1
D0
Y
W
G
GND
VCC
D4
D5
D6
D7
A
B
C
SN74F251B ...D OR N PACKAGE
(TOP VIEW)
3212019
910111213
4
5
6
7
8
18
17
16
15
14
D5
D6
NC
D7
A
D1
D0
NC
Y
W
SN54F251B . . . FK PACKAGE
(TOP VIEW)
D2
D3
NC
C
BD4
G
GND
NC
NC − No internal connection
VCC
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