1

FEATURES

GAB

NC

A1

A2

A3

A4

GND

1

2

3

4

5

6

7

V

CC

GBA

NC

B1

B2

B3

B4

14

13

12

11

10

9

8

DESCRIPTION

TYPICAL OF ALL OUTPUTS

V

CC

17 k

50

NOM

GND

V

CC

EQUIVALENT OF EACH INPUT

INPUT

OUTPUT

SN54LS243, SN74LS243

QUADRUPLE BUS TRANSCEIVERS

FUNCTION TABLE

• Two-Way Asynchronous Communication

(EACH TRANSCEIVER)

Between Data Buses

INPUTS

• PNP Inputs Reduce D-C Loading

SNxxLS243

GAB

GBA

• Hysteresis (Typically 400 mV) at Inputs

L

L

A to B

Improves Noise Margin

H

H

B to A

SN54LS243 . . . J OR W PACKAGE

H

L

Isolation

SN74LS243 . . . D, N, OR NS PACKAGE

L

H

Latch A and B

(TOP VIEW)

(A = B)

These four-data-line transceivers are designed for asynchronous two-way communications between data buses.

SN74LS243 can be used to drive terminated lines down to 133

Ω.

SN54LS243 is characterized for operation over the full military temperature range of –55°C to 125°C.

SN74LS243 is characterized for operation from 0°C to 70°C.

SCHEMATICS OF INPUTS AND OUTPUTS

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright © 1985–2008, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.