SDAS215A − APRIL 1982 − REVISED DECEMBER 1994
•
•
•
•
•
3-State Version of the ′ALS151
3-State Outputs Interface Directly With
System Bus
Perform Parallel-to-Serial Conversion
Complementary Outputs Provide True and
Inverted Data
Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
SN54ALS251 . . . J PACKAGE
SN74ALS251 . . . D OR N PACKAGE
(TOP VIEW)
D3
D2
D1
D0
Y
W
OE
GND
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
VCC
D4
D5
D6
D7
A
B
C
description
These data selectors/multiplexers contain full
binary decoding to select one-of-eight data
sources and feature controlled complementary
3-state outputs.
D2
D3
NC
VCC
D4
SN54ALS251 . . . FK PACKAGE
(TOP VIEW)
The 3-state outputs can interface with and drive
data lines of bus-organized systems. With all but
one of the common outputs disabled (at the
high-impedance state), the low impedance of the
signal-enabled output drives the bus line to a high
or low logic level. Both outputs are controlled by
the output-enable (OE) input. The outputs are
disabled when OE is high.
4
3 2 1 20 19
18
5
17
6
16
7
15
8
14
9 10 11 12 13
D5
D6
NC
D7
A
OE
GND
NC
C
B
D1
D0
NC
Y
W
The SN54ALS251 is characterized for operation
over the full military temperature range of − 55°C
to 125°C. The SN74ALS251 is characterized for
operation from 0°C to 70°C.
NC − No internal connection
FUNCTION TABLE
INPUTS
OUTPUTS
SELECT
OE
C
B
A
Y
W
X
X
X
H
Z
Z
L
L
L
L
D0
D0
L
L
H
L
D1
D1
L
H
L
L
D2
D2
L
H
H
L
D3
D3
H
L
L
L
D4
D4
H
L
H
L
D5
D5
H
H
L
L
D6
D6
H
H
H
L
D7
D7
D0, D1, . . . D7 = the level of the respective D input
Copyright 1994, Texas Instruments Incorporated
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• DALLAS, TEXAS 75265
• HOUSTON, TEXAS 77251−1443
POST OFFICE BOX 655303
POST OFFICE BOX 1443
1
SDAS215A − APRIL 1982 − REVISED DECEMBER 1994
logic symbol†
OE
A
B
C
D0
D1
D2
D3
D4
D5
D6
D7
7
11
MUX
EN
0
10
9
4
3
2
1
15
14
13
12
0
G7
2
0
5
1
6
2
Y
W
3
4
5
6
7
† 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.
logic diagram (positive logic)
OE
D0
D1
D2
D3
Data
Inputs
4
3
2
1
5
D4
D5
D6
D7
A
Data
Select
(binary)
7
B
C
15
6
14
13
12
11
10
9
Pin numbers shown are for the D, J, and N packages.
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POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
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Y
W
SDAS215A − APRIL 1982 − REVISED DECEMBER 1994
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Input voltage, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Voltage applied to a disabled 3-state output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Operating free-air temperature range, TA: SN54ALS251 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −55°C to 125°C
SN74ALS251 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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.
recommended operating conditions
SN54ALS251
SN74ALS251
MIN
NOM
MAX
MIN
NOM
MAX
4.5
5
5.5
4.5
5
5.5
UNIT
VCC
VIH
Supply voltage
VIL
IOH
Low-level input voltage
0.7
0.8
V
High-level output current
−1
−2.6
mA
IOL
TA
Low-level output current
24
mA
70
°C
High-level input voltage
2
2
V
12
Operating free-air temperature
−55
125
V
0
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
SN54ALS251
TYP‡
MAX
TEST CONDITIONS
MIN
VCC = 4.5 V,
VCC = 4.5 V to 5.5 V,
II = − 18 mA
IOH = − 0.4 mA
VCC = 4.5 V
IOH = − 1 mA
IOH = − 2.6 mA
VOL
VCC = 4.5 V
IOL = 12 mA
IOL = 24 mA
IOZH
IOZL
VCC = 5.5 V,
VCC = 5.5 V,
VO = 2.7 V
VO = 0.4 V
II
IIH
VCC = 5.5 V,
VCC = 5.5 V,
IIL
IO§
VCC = 5.5 V,
VCC = 5.5 V,
VOH
ICC
Enabled
Disabled
VCC = 5.5 V
SN74ALS251
TYP‡
MAX
MIN
−1.5
VCC − 2
2.4
−1.5
UNIT
V
VCC − 2
3.3
V
2.4
0.25
0.4
3.2
0.25
0.4
0.35
0.5
V
20
20
µA
−20
−20
µA
VI = 7 V
VI = 2.7 V
0.1
0.1
mA
20
20
µA
VI = 0.4 V
VO = 4.5 V
−0.1
−0.1
mA
−112
mA
−20
−112
−30
Inputs at GND
7
10
7
10
Inputs at 4.5 V
9.4
14
9.4
14
mA
‡ All typical values are at VCC = 5 V, TA = 25°C.
§ The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
3
SDAS215A − APRIL 1982 − REVISED DECEMBER 1994
switching characteristics (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
tPLH
tPHL
A, B, or C
Y
tPLH
tPHL
A, B, or C
W
tPLH
tPHL
Any D
Y
tPLH
tPHL
Any D
W
tPZH
tPZL
OE
Y
tPZH
tPZL
OE
W
tPZH
tPZL
OE
Y
tPZH
tPZL
OE
W
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
TA = MIN to MAX†
SN54ALS251 SN74ALS251
MIN
MAX
MIN
MAX
1
21
5
18
7
34
8
24
5
38
8
24
7
26
7
23
2
15
2
10
3
23
3
15
3
25
3
15
3
20
3
15
3
21
3
15
3
19
3
15
3
21
3
15
3
19
3
15
2
12
2
10
1
18
1
10
2
12
2
10
1
18
1
10
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
4
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
UNIT
ns
ns
ns
ns
ns
ns
ns
ns
SDAS215A − APRIL 1982 − REVISED DECEMBER 1994
PARAMETER MEASUREMENT INFORMATION
SERIES 54ALS/74ALS AND 54AS/74AS DEVICES
7V
RL = R1 = R2
VCC
S1
RL
R1
Test
Point
From Output
Under Test
CL
(see Note A)
From Output
Under Test
RL
Test
Point
CL
(see Note A)
CL
(see Note A)
LOAD CIRCUIT FOR
BI-STATE
TOTEM-POLE OUTPUTS
LOAD CIRCUIT
FOR OPEN-COLLECTOR OUTPUTS
3.5 V
Timing
Input
Test
Point
From Output
Under Test
LOAD CIRCUIT
FOR 3-STATE OUTPUTS
3.5 V
High-Level
Pulse
1.3 V
R2
1.3 V
1.3 V
0.3 V
0.3 V
tsu
Data
Input
tw
th
3.5 V
1.3 V
3.5 V
Low-Level
Pulse
1.3 V
0.3 V
1.3 V
0.3 V
VOLTAGE WAVEFORMS
PULSE DURATIONS
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
3.5 V
Output
Control
(low-level
enabling)
1.3 V
1.3 V
0.3 V
tPZL
Waveform 1
S1 Closed
(see Note B)
tPLZ
3.5 V
Input
tPZH
1.3 V
0.3 V
tPHL
tPLH
VOH
In-Phase
Output
VOL
0.3 V
1.3 V
1.3 V
VOL
tPLH
tPHL
VOH
1.3 V
1.3 V
[3.5 V
1.3 V
tPHZ
Waveform 2
S1 Open
(see Note B)
1.3 V
VOH
Out-of-Phase
Output
(see Note C)
0.3 V
[0 V
1.3 V
1.3 V
VOL
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. When measuring propagation delay items of 3-state outputs, switch S1 is open.
D. All input pulses have the following characteristics: PRR ≤ 1 MHz, tr = tf = 2 ns, duty cycle = 50%.
E. The outputs are measured one at a time with one transition per measurement.
Figure 1. Load Circuits and Voltage Waveforms
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443
•
5
PACKAGE OPTION ADDENDUM
www.ti.com
23-Sep-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
84135012A
ACTIVE
LCCC
FK
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
84135012A
SNJ54ALS
251FK
8413501EA
ACTIVE
CDIP
J
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8413501EA
SNJ54ALS251J
Samples
8413501FA
ACTIVE
CFP
W
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8413501FA
SNJ54ALS251W
Samples
SN54ALS251J
ACTIVE
CDIP
J
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SN54ALS251J
Samples
SN74ALS251D
ACTIVE
SOIC
D
16
40
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS251
Samples
SN74ALS251DR
ACTIVE
SOIC
D
16
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS251
Samples
SN74ALS251N
ACTIVE
PDIP
N
16
25
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
SN74ALS251N
Samples
SNJ54ALS251FK
ACTIVE
LCCC
FK
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
84135012A
SNJ54ALS
251FK
SNJ54ALS251J
ACTIVE
CDIP
J
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8413501EA
SNJ54ALS251J
Samples
SNJ54ALS251W
ACTIVE
CFP
W
16
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8413501FA
SNJ54ALS251W
Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of