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SN74ALS642A-1DWR

Part # SN74ALS642A-1DWR
Description IC BUS TRANSCEIVER DUAL 20SOIC
Category IC
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Texas Instruments
Date Code: 0614
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Technical Document


DISCLAIMER: The information provided herein is solely for informational purposes. Customers must be aware of the suitability of this product for their application, and consider that variable factors such as Manufacturer, Product Category, Date Codes, Pictures and Descriptions may differ from available inventory.

SN74ALS641A, SN74ALS642A, SN74AS641
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDAS300 – MARCH 1995
Copyright 1995, Texas Instruments Incorporated
1
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
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
LOGIC
SN74ALS641A, SN74AS641 True
SN74ALS642A Inverting
description
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.
FUNCTION TABLE
INPUTS
OPERATION
OE DIR
SN74ALS641A
SN74AS641
SN74ALS642A
L L B data to A bus B data to A bus
L H A data to B bus A data to B bus
H X Isolation Isolation
logic symbols
B2
17
B3
16
B4
15
A5
6
A6
7
A7
8
A8
9
A2
3
A3
4
A4
5
OE
A1
2
G3
19
3 EN2 [AB]
B5
14
B6
13
B7
12
B8
11
B1
18
3 EN1 [BA]
1
DIR
1
2
SN74ALS641A, SN74AS641
B2
17
B3
16
B4
15
A5
6
A6
7
A7
8
A8
9
A2
3
A3
4
A4
5
OE
A1
2
G3
19
3 EN2 [AB]
B5
14
B6
13
B7
12
B8
11
B1
18
3 EN1 [BA]
1
DIR
1
2
SN74ALS642A
These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
DIR
A1
A2
A3
A4
A5
A6
A7
A8
GND
V
CC
OE
B1
B2
B3
B4
B5
B6
B7
B8
DW OR N PACKAGE
(TOP VIEW)
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.
SN74ALS641A, SN74ALS642A, SN74AS641
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDAS300 – MARCH 1995
2
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
logic diagrams (positive logic)
SN74ALS641A, SN74AS641
A1
B1
19
1
18
2
OE
DIR
To Seven Other Transceivers
SN74ALS642A
A1
B1
19
1
18
2
OE
DIR
To Seven Other Transceivers
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, V
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
I
: All inputs and I/O ports 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
: SN74ALS641A, SN74ALS642A 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
SN74ALS641A
SN74ALS642A
UNIT
MIN NOM MAX
V
CC
Supply voltage 4.5 5 5.5 V
V
IH
High-level input voltage 2 V
V
IL
Low-level input voltage 0.8 V
V
OH
High-level output voltage 5.5 V
I
OL
Low level out
p
ut current
24
mA
I
OL
Lo
w-
le
v
el
o
u
tp
u
t
c
u
rrent
48
mA
T
A
Operating free-air temperature 0 70 °C
Applies only to the -1 version and only if V
CC
is between 4.75 V and 5.25 V
SN74ALS641A, SN74ALS642A, SN74AS641
OCTAL BUS TRANSCEIVERS
WITH OPEN-COLLECTOR OUTPUTS
SDAS300 – MARCH 1995
3
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER TEST CONDITIONS
SN74ALS641A
SN74ALS642A
UNIT
MIN TYP
MAX
V
IK
V
CC
= 4.5 V, I
I
= –18 mA 1.5 V
I
OH
V
CC
= 4.5 V, V
OH
= 5.5 V 0.1 mA
I
OL
= 12 mA 0.25 0.4
V
OL
V
CC
= 4.5 V
I
OL
= 24 mA 0.35 0.5
V
I
OL
= 48 mA
0.35 0.5
I
I
Control inputs V
CC
= 5.5 V, V
I
= 7 V 0.1 mA
I
IH
Control inputs
V
CC
=55V
V
I
=27V
20
µA
I
IH
A or B ports
§
V
CC
=
5
.
5
V
,
V
I
=
2
.
7
V
20
µ
A
I
IL
Control inputs
V
CC
=55V
V
I
=04V
0.1
mA
I
IL
A or B ports
§
V
CC
=
5
.
5
V
,
V
I
=
0
.
4
V
0.1
mA
SN74ALS641A
V
CC
=55V
Outputs high 25 37
I
CC
SN74ALS641A
V
CC
=
5
.
5
V
Outputs low 33 47
mA
I
CC
SN74ALS642A
V
CC
=55V
Outputs high 8 15
mA
SN74ALS642A
V
CC
=
5
.
5
V
Outputs low 18 28
All typical values are at V
CC
= 5 V, T
A
= 25°C.
Applies only to the -1 version and only if V
CC
is between 4.75 V and 5.25 V
§
For I/O ports, the parameters I
IH
and I
IL
include the off-state output current.
switching characteristics (see Figure 1)
PARAMETER
FROM
(
INPUT
)
TO
(
OUTPUT
)
V
CC
= 4.5 V to 5.5 V,
C
L
= 50 pF,
R
L
= 680
,
T
A
= MIN to MAX
UNIT
(INPUT)
(OUTPUT)
SN74ALS641A SN74ALS642A
MIN MAX MIN MAX
t
PLH
AorB
BorA
5 25 10 30
ns
t
PHL
A
or
B
B
or
A
3 18 5 22
ns
t
PLH
OE
AorB
8 30 10 30
ns
t
PHL
OE
A
or
B
8 30 15 38
ns
t
PLH
DIR
AorB
8 32 10 30
ns
t
PHL
DIR
A
or
B
8 32 15 38
ns
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
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