Texas Instruments 8414301DA Datasheet

SN54ALS21A, SN54AS21, SN74ALS21A, SN74AS21

DUAL 4-INPUT POSITIVE-AND GATES

SDAS085B – APRIL 1982 – REVISED DECEMBER 1994

Copyright  1994, Texas Instruments Incorporated

1

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

• 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-AND gates. They perform the Boolean
functions Y = A • B • C • D or Y = A

+ B + C + D

in positive logic.
The SN54ALS21A and SN54AS21 are

characterized for operation over the full military
temperature range of –55°C to 125°C. The
SN74ALS21A and SN74AS21 are characterized
for operation from 0°C to 70°C.

FUNCTION TABLE
(each gate)

INPUTS

OUTPUT

A B C D

Y

H H H H H
L XXX L
XLXX L
XXLX L
XXXL L

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.

SN54ALS21A, SN54AS21 ...J PACKAGE

SN74ALS21A, SN74AS21 ...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

SN54ALS21A, SN54AS21 . . . 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

1B1ANC

2Y

2A

V

2D

1Y

NC

CC

NC – No internal connection

GND

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.

SN54ALS21A, SN54AS21, SN74ALS21A, SN74AS21
DUAL 4-INPUT POSITIVE-AND GATES

SDAS085B – APRIL 1982 – REVISED DECEMBER 1994

2

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

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

: SN54ALS21A –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN74ALS21A 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

SN54ALS21A SN74ALS21A

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

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

electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)

SN54ALS21A SN74ALS21A

PARAMETER

TEST CONDITIONS

MIN TYP‡MAX MIN TYP‡MAX

UNIT

V

IK

VCC = 4.5 V, II = –18 mA –1.5 –1.5 V

V

OH

VCC = 4.5 V to 5.5 V, IOH = –0.4 mA VCC –2 VCC –2 V

IOL = 4 mA 0.25 0.4 0.25 0.4

V

OL

V

CC

= 4.5

V

IOL = 8 mA 0.35 0.5

V

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 = 0.4 V –0.1 –0.1 mA

I

O

§

VCC = 5.5 V, VO = 2.25 V –20 –112 –30 –112 mA

I

CCH

VCC = 5.5 V, VI = 4.5 V 0.85 1.4 0.85 1.4 mA

I

CCL

VCC = 5.5 V, VI = 0 1.4 2.3 1.4 2.3 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.

switching characteristics (see Figure 1)

PARAMETER

FROM

(

INPUT

)

TO

(

OUTPUT

)

VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500 Ω,
TA = MIN to MAX

¶

UNIT

(INPUT)

(OUTPUT)

SN54ALS21A SN74ALS21A

MIN MAX MIN MAX

t

PLH

4 18 4 15

t

PHL

A, B, C, or D

Y

2 15 2 10

ns

¶

For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.