Texas Instruments SN54HC251J, SN74HC251D, SN74HC251DBR, SN74HC251DR, SN74HC251N Datasheet
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SN54HC251, SN74HC251
DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SCLS132C – DECEMBER 1982 – REVISED FEBRUARY 1999
D
3-State Version of ’HC151
D
High-Current 3-State Outputs Interface
Directly With System Bus or Can Drive up
to 15 LSTTL Loads
D
Perform Parallel-to-Serial Conversion
D
Complementary Outputs Provide True and
Inverted Data
D
Package Options Include Plastic
Small-Outline (D), Shrink Small-Outline
(DB), and Ceramic Flat (W) Packages,
Ceramic Chip Carriers (FK), and Standard
Plastic (N) and Ceramic (J) DIPs
description
These data selectors/multiplexers contain full
binary decoding to select 1-of-8 data sources and
feature strobe-controlled complementary 3-state
outputs.
The 3-state outputs can interface with and drive
data lines of bus-organized systems. With all but
one of the common outputs disabled (in the
high-impedance state), the low impedance of the
single enabled output drives the bus line to a high
or low logic level. Both outputs are controlled by
the output-enable (OE
disabled when OE
The SN54HC251 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74HC251 is characterized for
operation from –40°C to 85 °C.
) input. The outputs are
is high.
SN54HC251 ...J OR W PACKAGE
SN74HC251 . . . D, DB, OR N PACKAGE
SN54HC251 . . . FK PACKAGE
D1
D0
NC
Y
W
NC – No internal connection
(TOP VIEW)
D3
1
D2
2
D1
3
D0
4
Y
5
W
6
OE
7
GND
8
(TOP VIEW)
D2D3NC
3212019
4
5
6
7
8
910111213
OE
GND
NC
16
15
14
13
12
11
10
9
V
C
CC
V
D4
D5
D6
D7
A
B
C
D4
18
17
16
15
14
B
CC
D5
D6
NC
D7
A
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 1999, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
1
SN54HC251, SN74HC251
OE
Y
W
DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SCLS132C – DECEMBER 1982 – REVISED FEBRUARY 1999
C B A
X X X H Z Z
L LLLD0 D0
L LHLD1 D1
L HLLD2 D2
L HHLD3 D3
H LLLD4 D4
H LHLD5 D5
H HLLD6 D6
H H H L D7 D7
D0, D1 . . . D7 = the level of the respective D input
FUNCTION TABLE
INPUTS
SELECT
OUTPUTS
logic symbol
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the D, DB, J, N, and W packages.
†
OE
D0
D1
D2
D3
D4
D5
D6
D7
7
11
A
10
B
9
C
4
3
2
1
15
14
13
12
EN
0
2
0
1
2
3
4
5
6
7
MUX
G
0
7
5
Y
6
W
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic diagram (positive logic)
7
OE
11
A
10
B
9
C
4
D0
3
D1
SN54HC251, SN74HC251
DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SCLS132C – DECEMBER 1982 – REVISED FEBRUARY 1999
TG
TG
2
D2
1
D3
15
D4
14
D5
13
D6
12
D7
Pin numbers shown are for the D, DB, J, N, and W packages.
TG
TG
TG
TG
TG
TG
5
Y
6
W
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
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