SN54F257, SN74F257
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SDFS065A – D2932, MARCH 1987 – REVISED OCTOBER 1993
Copyright 1993, Texas Instruments Incorporated
2–1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
• 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.
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
OUTPUT
OE A/B A B
Y
H X X X Z
L LLX L
LLHX H
LHXL L
LHXH H
logic symbol
†
OE
MUX
2
1A
1
3
1B
EN
15
G1
1
1Y
4
5
2A
6
2B
2Y
7
11
3A
10
3B
3Y
9
14
4A
13
4B
4Y
12
A/B
1
†
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.
SN54F257 ...J PACKAGE
SN74F257 ...D OR N PACKAGE
(TOP VIEW)
3212019
910111213
4
5
6
7
8
18
17
16
15
14
4A
4B
NC
4Y
3A
1B
1Y
NC
2A
2B
SN54F257 . . . FK PACKAGE
(TOP VIEW)
1A
A/B
NC
3Y
3B
OE
2Y
GND
NC
NC – No internal connection
V
CC
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
A/B
1A
1B
1Y
2A
2B
2Y
GND
V
CC
OE
4A
4B
4Y
3A
3B
3Y
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.
SN54F257, SN74F257
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SDFS065A – D2932, MARCH 1987 – REVISED OCT OBER 1993
2–2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic diagram (positive logic)
4Y
3Y
2Y
1Y
A
/B
OE
4B
4A
3B
3A
2B
2A
1B
1A
4
2
3
7
5
6
9
11
10
12
14
13
1
15
Pin numbers shown are for the D, J, and N packages.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage range, V
CC
–0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage range (see Note 1) –1.2 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input current range –30 mA to 5 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the disabled or power-off state –0.5 V to 5.5 V. . . . . . . . . . . . . . . . . . .
Voltage range applied to any output in the high state –0.5 V to V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current into any output in the low state: SN54F257 40 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74F257 48 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range: SN54F257 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74F257 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTE 1: The input voltage ratings may be exceeded provided the input current ratings are observed.
SN54F257, SN74F257
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SDFS065A – D2932, MARCH 1987 – REVISED OCTOBER 1993
2–3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
recommended operating conditions
SN54F257 SN74F257
MIN NOM MAX MIN NOM MAX
UNIT
V
CC
Supply voltage 4.5 5 5.5 4.5 5 5.5 V
V
IH
High-level input voltage 2 2 V
V
IL
Low-level input voltage 0.8 0.8 V
I
IK
Input clamp current –18 –18 mA
I
OH
High-level output current –3 –3 mA
I
OL
Low-level output current 20 24 mA
T
A
Operating free-air temperature –55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54F257 SN74F257
PARAMETER
TEST CONDITIONS
MIN TYP†MAX MIN TYP†MAX
UNIT
V
IK
VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
IOH = – 1 mA 2.5 3.4 2.5 3.4
V
OH
V
CC
=
4.5 V
IOH = – 3 mA 2.4 3.3 2.4 3.3 V
VCC = 4.75 V , IOH = – 1 mA to –3 mA 2.7
IOL = 20 mA 0.3 0.5
V
OL
V
CC
= 4.5
V
IOL = 24 mA 0.35 0.5
V
I
OZH
VCC = 5.5 V, VO = 2.7 V 50 50 µA
I
OZL
VCC = 5.5 V, VO = 0.5 V –50 –50 µA
I
I
VCC = 5.5 V, VI = 7 V 0.1 0.1 mA
I
IH
VCC = 5.5 V, VI = 2.7 V 20 20 µA
I
IL
VCC = 5.5 V, VI = 0.5 V – 0.6 – 0.6 mA
I
OS
‡
VCC = 5.5 V, VO = 0 –60 –150 –60 –150 mA
I
CCH
Condition A 9 15 9 15
I
CCL
V
CC
= 5.5 V,
Condition B 14.5 22 14.5 22
mA
I
CCZ
See Note 2
Condition C 15 23 15 23
†
All typical values are at VCC = 5 V, TA = 25°C.
‡
Not more than one output should be shorted at a time, and the duration of the short circuit should not exceed one second.
NOTE 2: ICC is measured with the outputs open under the following conditions:
A. A
/B and all B inputs at 4.5 V , other inputs grounded
B. All B inputs at 4.5 V , other inputs grounded
C. OE
and all B data inputs at 4.5 V , other inputs grounded
SN54F257, SN74F257
QUADRUPLE 2-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS
WITH 3-STATE OUTPUTS
SDFS065A – D2932, MARCH 1987 – REVISED OCT OBER 1993
2–4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics (see Note 3)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
VCC = 5 V,
CL = 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
TA = 25°C
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500Ω,
R2 = 500 Ω,
TA = MIN to MAX
†
UNIT
′F257 SN54F257 SN74F257
MIN TYP MAX MIN MAX MIN MAX
t
PLH
2.2 4.1 6 2.2 8 2.2 7
t
PHL
A or B
Any Y
1.2 3.8 5.5 1 8 1.2 6.5
ns
t
PLH
3.7 9.7 13 3.7 15.5 3.7 15
t
PHL
A/B
Any Y
2.7 6.1 8.5 2.7 10.5 2.7 9.5
ns
t
PZH
2.2 5.5 7.5 2.2 9.5 2.2 8.5
t
PZL
G
Any Y
2.2 5.1 7.5 2.2 10 2.2 8.5
ns
t
PHZ
1.2 3.9 6 1.2 7 1.2 7
t
PLZ
G
Any Y
1.2 4.1 6 1.2 9.5 1.2 7
ns
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
NOTE 3: Load circuits and waveforms are shown in Section 1.
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accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
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Copyright 1998, Texas Instruments Incorporated
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