SN74ALS641A Datasheet, PDF (1/7 Pages) Texas Instruments – OCTAL BUS TRANSCEIVERS WITH OPEN-COLLECTOR OUTPUTS

• Bidirectional Bus Transceivers in
High-Density 20-Pin Packages
• Choice of True or Inverting Logic
• Package Options Include Plastic
Small-Outline (DW) Packages and
Standard Plastic (N) 300-mil DIPs
DEVICE
SN74ALS641A, SN74AS641
SN74ALS642A
LOGIC
True
Inverting
description
SN74ALS641A, SN74ALS642A, SN74AS641
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDAS300 – MARCH 1995
DW OR N PACKAGE
(TOP VIEW)
DIR 1
A1 2
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8
A8 9
GND 10
20 V_CC
19 OE
18 B1
17 B2
16 B3
15 B4
14 B5
13 B6
12 B7
11 B8
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. These devices transmit data from the A bus to the B bus or from the B bus to the A bus, depending
upon the level at the direction-control (DIR) input. The output-enable (OE) input disables the device so that the
buses are effectively isolated.
The -1 versions of the SN74ALS641A and SN74ALS642A are identical to the standard versions, except that
the recommended maximum I_OL is increased to 48 mA in the -1 versions.
The SN74ALS641A, SN74ALS642A, and SN74AS641 are characterized for operation from 0°C to 70°C.
INPUTS
OE DIR
L
L
L
H
H
X
FUNCTION TABLE
OPERATION
SN74ALS641A
SN74AS641
SN74ALS642A
B data to A bus B data to A bus
A data to B bus
Isolation
A data to B bus
Isolation
logic symbols^†
19
OE
1
DIR
SN74ALS641A, SN74AS641
G3
3 EN1 [BA]
3 EN2 [AB]
19
OE
1
DIR
2
A1
3
A2
4
A3
5
A4
6
A5
7
A6
8
A7
9
A8
1
2
18
B1
17
B2
16
B3
15
B4
14
B5
13
B6
12
B7
11
B8
2
A1
3
A2
4
A3
5
A4
6
A5
7
A6
8
A7
9
A8
† _{These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.}
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.
SN74ALS642A
G3
3 EN1 [BA]
3 EN2 [AB]
1
2
18
B1
17
B2
16
B3
15
B4
14
B5
13
B6
12
B7
11
B8
Copyright © 1995, Texas Instruments Incorporated
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1