Philips 74als240a DATASHEETS

INTEGRATED CIRCUITS

74ALS240A/74ALS240A–1

Octal inverter buffer (3–State)

Product specification IC05 Data Handbook

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1991 Feb 08

Philips Semiconductors Product specification

Octal inverter buffer (3-State)

FEA TURES

•Octal bus interface

•3-State buffer outputs sink 24mA and source 15mA

•The -1 version sinks 48 mA

DESCRIPTION

The 74ALS240A is an octal buffer that is ideal for driving bus lines or buffer memory address registers. The outputs are all capable of sinking 24mA and sourcing up to 15mA, producing very good capacitive drive characteristics. The device features two output enables, OE

The 74ALS240A-1 sinks 48 mA IOL if the VCC is limited to

5.0V ±0.25V.

74ALS240A-1 4.5ns 15mA

a and OEb, each controlling four of the 3-State outputs.

TYPE

TYPICAL

PROPAGATION

DELAY

TYPICAL

SUPPLY CURRENT

(TOTAL)

74ALS240A 4.5ns 15mA

PIN CONFIGURATION

1

OEa

2

Ia0

3

Y

b0

4

Ia1

b1

5

Y

Ia2

6

b2

Y

7

Ia3

8

Y

b3

9

GND

10 11

ORDERING INFORMA TION

ORDER CODE

COMMERCIAL RANGE

DESCRIPTION

20-pin plastic DIP

20-pin plastic SOL

20-pin plastic SSOP

Type II

V

CC

T

amb

74ALS240AN,

74ALS240A-1N

74ALS240AD,

74ALS240A-1D

74ALS240ADB,

74ALS240A-1DB

74ALS240A/

74ALS240A-1

V

20

CC

19

OEb

18

a0

Y

17

Ib0

a1

16

Y Ib1

15

a2

Y

14

Ib2

13

Y

a3

12

Ib3

= 5V ±10%,

= 0°C to +70°C

SF00320

DRAWING

NUMBER

SOT146-1

SOT163-1

SOT339-1

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

PINS DESCRIPTION

Ian, Ibn Data inputs 1.0/1.0 20µA/0.1mA

OEa, OEb Output Enable inputs (active-Low) 1.0/1.0 20µA/0.1mA

Yan, Ybn Data outputs 750/240 15mA/24mA Yan, Ybn Data outputs (-1 version) 750/480 15mA/48mA

NOTE: One (1.0) ALS unit load is defined as: 20µA in the High state and 0.1mA in the Low state.

LOGIC SYMBOL

119OEa

VCC = Pin 20 GND = Pin 10

2 4 6 8 17 15 13 11

Ia0 Ia1 Ia2 Ia3 Ib0 Ib1 Ib2 Ib3

OEb

Ya0 Ya1 Ya2 Ya3 Yb0 Yb1 Yb2 Yb3

181614123579

SF00321

IEC/IEEE SYMBOL

74ALS (U.L.)

HIGH/LOW

1

19

17 15

13

11

EN1 EN2

2 4 6 8

2D

1

2

LOAD VALUE

HIGH/LOW

18 16 14 12

3 5 7 9

SF00322

1991 Feb 08 853–1244 01670

2

Philips Semiconductors Product specification

I

Current applied to output in Low output state

SYMBOL

UNIT

IOLLow-level output current

Octal inverter buffer (3-State)

LOGIC DIAGRAM

OE

Ib0

Ib1

Ib2

Ib3

17

15

13

11

10

b

3

5

7

9

SF00323

Yb0

Yb1

Y

b2

b3

Ia0

Ia1

Ia2

Ia3

OE

a

VCC = Pin 20 GND = Pin 10

2

4

6

8

1

18

Y

a0

16

Ya1

14

Y

a2

12

Y

a3

ABSOLUTE MAXIMUM RATINGS

(Operation beyond the limit set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the operating free air temperature range.)

SYMBOL

V

CC

V

IN

I

IN

V

OUT

T

amb

T

stg

Supply voltage –0.5 to +7.0 V Input voltage –0.5 to +7.0 V Input current –30 to +5 mA Voltage applied to output in High output state –0.5 to V

pp

p

Operating free-air temperature range 0 to +70 °C Storage temperature range –65 to +150 °C

PARAMETER RATING UNIT

p

FUNCTION TABLE

OEa Ia OEb Ib Ya Yb

L L L L H H L H L H L L

H X H X Z Z

H = High voltage level L = Low voltage level X = Don’t care Z = High impedance “off” state

All versions 48 mA

-1 version 96 mA

74ALS240A/

74ALS240A-1

INPUTS OUTPUTS

CC

V

RECOMMENDED OPERATING CONDITIONS

PARAMETER

V

CC

V V

I

IK

I

OH

T

amb

NOTE:

1. The 48mA limit applies only under the condition of V

Supply voltage 4.5 5.0 5.5 V High-level input voltage 2.0 V

IH

Low-level input voltage 0.8 V

IL

Input clamp current –18 mA High-level output current –15 mA

p

Operating free-air temperature range 0 +70 °C

CC

= 5.0V ±5%.

LIMITS

MIN NOM MAX

All versions 24 mA

-1 version 48

1

mA

1991 Feb 08

3