SN54F257_08 Datasheet, PDF (1/5 Pages) Texas Instruments – QUADRUPLE 2-LINE TO 1-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS WITH 3-STATE OUTPUTS

SN54F257, SN74F257
QUADRUPLE 2ĆLINE TO 1ĆLINE DATA SELECTORS/MULTIPLEXERS
WITH 3ĆSTATE OUTPUTS
SDFS065A − D2932, MARCH 1987 − REVISED OCTOBER 1993
• 3-State Outputs Interface Directly With
System Bus
• Provides Bus Interface From Multiple
Sources in High-Performance Systems
• Package Options Include Plastic
Small-Outline Packages, Ceramic Chip
Carriers, and Standard Plastic and Ceramic
300-mil DIPs
description
The ′F257 is designed to multiplex signals from
4-bit data sources to 4-output data lines in
bus-organized systems. The 3-state outputs will
not load the data lines when the output enable
(OE) input is at a high logic level.
SN54F257 . . . J PACKAGE
SN74F257 . . . D OR N PACKAGE
(TOP VIEW)
A /B 1
1A 2
1B 3
1Y 4
2A 5
2B 6
2Y 7
GND 8
16 V_CC
15 OE
14 4A
13 4B
12 4Y
11 3A
10 3B
9 3Y
SN54F257 . . . FK PACKAGE
(TOP VIEW)
The SN54F257 is characterized for operation over
the full military temperature range of − 55°C to
125°C. The SN74F257 is characterized for
operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
OE A /B A
OUTPUT
B
Y
H
X
X
X
Z
L
L
L
X
L
L
L
H
X
H
L
H
X
L
L
L
H
X
H
H
1B
3 2 1 20 19
4
18
4A
1Y ₅
17 ^4B
NC 6
16 NC
2A 7
15 4Y
2B 8
14 3A
9 10 11 12 13
NC − No internal connection
logic symbol^†
15
OE
1
A /B
2
1A
3
1B
5
2A
6
2B
11
3A
10
3B
14
4A
13
4B
EN
G1
1 ^MUX
1
4
1Y
7
2Y
9
3Y
12
4Y
† _{This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.}
Pin numbers shown are for the D, J, and N packages.
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.
Copyright  1993, Texas Instruments Incorporated
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
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