SDAS192B − APRIL 1982 − REVISED DECEMBER 1994
Copyright 1994, Texas Instruments Incorporated
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443
• Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
description
These devices contain two independent 4-input
positive-NAND gates. They perform the Boolean
functions Y = A
• B • C • D or Y = A + B + C + D
in positive logic.
The SN54ALS20A and SN54AS20 are
characterized for operation over the full military
temperature range of −55°C to 125°C. The
SN74ALS20A and SN74AS20 are characterized
for operation from 0°C to 70°C.
FUNCTION TABLE
(each gate)
INPUTS
A B C D
Y
H H H H L
L XXX H
X LXX H
X XLX H
X X X L H
logic symbol
†
logic diagram (positive logic)
&
1Y
6
2Y
8
1
1A
2
1B
4
1C
5
1D
9
2A
10
2B
12
2C
13
2D
1Y
1D
1A
1B
1C
2C
2B
2A
2D
2Y
1
2
4
5
9
10
12
13
6
8
†
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.
SN54ALS20A, SN54AS20 ...J PACKAGE
SN74ALS20A, SN74AS20 ...D OR N PACKAGE
(TOP VIEW)
1
2
3
4
5
6
7
14
13
12
11
10
9
8
1A
1B
NC
1C
1D
1Y
GND
V
CC
2D
2C
NC
2B
2A
2Y
SN54ALS20A, SN54AS20 . . . FK PACKAGE
(TOP VIEW)
3 2 1 20 19
9 10 11 12 13
4
5
6
7
8
18
17
16
15
14
2C
NC
NC
NC
2B
NC
NC
1C
NC
1D
1B
1A
NC
2Y
2A
V
2D
1Y
NC
CC
NC − No internal connection
GND
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(#"! " !%$""! %$ *$ $! $+! !#$!
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SDAS192B − APRIL 1982 − REVISED DECEMBER 1994
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443
• HOUSTON, TEXAS 77251−1443
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage, V
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
I
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
: SN54ALS20A −55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74ALS20A 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
SN54ALS20A SN74ALS20A
MIN NOM MAX MIN NOM MAX
V
CC
Supply voltage 4.5 5 5.5 4.5 5 5.5 V
V
IH
High-level input voltage 2 2 V
0.8
‡
0.8
V
IL
Low-level input voltage
0.7
§
V
I
OH
High-level output current −0.4 −0.4 mA
I
OL
Low-level output current 4 8 mA
T
A
Operating free-air temperature −55 125 0 70 °C
‡
Applies over temperature range −55°C to 70°C
§
Applies over temperature range 70°C to 125°C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54ALS20A SN74ALS20A
MIN TYP
¶
MAX MIN TYP
¶
MAX
V
IK
V
CC
= 4.5 V, I
I
= −18 mA −1.5 −1.5 V
V
OH
V
CC
= 4.5 V to 5.5 V, I
OH
= −0.4 mA V
CC
−2 V
CC
−2 V
I
OL
= 4 mA 0.25 0.4 0.25 0.4
V
OL
V
CC
= 4.5 V
I
OL
= 8 mA 0.35 0.5
V
I
I
V
CC
= 5.5 V, V
I
= 7 V 0.1 0.1 mA
I
IH
V
CC
= 5.5 V, V
I
= 2.7 V 20 20 µA
I
IL
V
CC
= 5.5 V, V
I
= 0.4 V −0.1 −0.1 mA
I
O
#
V
CC
= 5.5 V, V
O
= 2.25 V −20 −112 −30 −112 mA
I
CCH
V
CC
= 5.5 V, V
I
= 0 0.22 0.4 0.22 0.4 mA
I
CCL
V
CC
= 5.5 V, V
I
= 4.5 V 0.81 1.5 0.81 1.5 mA
¶
All typical values are at V
CC
= 5 V, T
A
= 25°C.
#
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, I
OS
.
SDAS192B − APRIL 1982 − REVISED DECEMBER 1994
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443
• HOUSTON, TEXAS 77251−1443
switching characteristics (see Figure 1)
PARAMETER
FROM
TO
V
CC
= 4.5 V to 5.5 V,
C
L
= 50 pF,
R
L
= 500 Ω,
T
A
= MIN to MAX
†
UNIT
SN54ALS20A SN74ALS20A
MIN MAX MIN MAX
t
PLH
1 12.5 3 11
t
PHL
1 11 3 10
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
‡
Supply voltage, V
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
I
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
: SN54AS20 −55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74AS20 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
SN54AS20 SN74AS20
MIN NOM MAX MIN NOM MAX
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
OH
High-level output current −2 −2 mA
I
OL
Low-level output current 20 20 mA
T
A
Operating free-air temperature −55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54AS20 SN74AS20
MIN TYP
§
MAX MIN TYP
§
MAX
V
IK
V
CC
= 4.5 V, I
I
= −18 mA −1.2 −1.2 V
V
OH
V
CC
= 4.5 V to 5.5 V, I
OH
= −2 mA V
CC
−2 V
CC
−2 V
V
OL
V
CC
= 4.5 V, I
OL
= 20 mA 0.35 0.5 0.35 0.5 V
I
I
V
CC
= 5.5 V, V
I
= 7 V 0.1 0.1 mA
I
IH
V
CC
= 5.5 V, V
I
= 2.7 V 20 20 µA
I
IL
V
CC
= 5.5 V, V
I
= 0.4 V −0.5 −0.5 mA
I
O
¶
V
CC
= 5.5 V, V
O
= 2.25 V −30 −112 −30 −112 mA
I
CCH
V
CC
= 5.5 V, V
I
= 0 1 1.6 1 1.6 mA
I
CCL
V
CC
= 5.5 V, V
I
= 4.5 V 5.4 8.7 5.4 8.7 mA
§
All typical values are at V
CC
= 5 V, T
A
= 25°C.
¶
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, I
OS
.
