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SN74ALS1640A Datasheet, PDF (1/5 Pages) Texas Instruments – OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS
SN74ALS1640A, SN74ALS1645A
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS246B – DECEMBER 1982 – REVISED FEBRUARY 1997
D Bidirectional Bus Transceivers in
High-Density 20-Pin Packages
DW OR N PACKAGE
(TOP VIEW)
D Lower-Power Versions of SN74ALS640B
and SN74ALS645A
D Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic (N) 300-mil DIPs
DIR 1
A1 2
A2 3
A3 4
A4 5
20 VCC
19 OE
18 B1
17 B2
16 B3
description
A5 6
A6 7
15 B4
14 B5
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. These devices transmit data from the
A7 8
A8 9
GND 10
13 B6
12 B7
11 B8
A bus to the B bus or from the B bus to the A bus,
depending on the level at the direction-control
(DIR) input. The output-enable (OE) input can be used to disable the device so that the buses are effectively
isolated. The SN74ALS1640A features inverting logic, while the SN74ALS1645A features noninverting logic.
The SN74ALS1640A and SN74ALS1645A are characterized for operation from 0°C to 70°C.
INPUTS
OE DIR
L
L
L
H
H
X
FUNCTION TABLE
OPERATION
SN74ALS1640A SN74ALS1645A
B data to A bus B data to A bus
A data to B bus A data to B bus
Isolation
Isolation
logic symbols†
SN74ALS1640A
19
OE
1
DIR
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.
SN74ALS1645A
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
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.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright © 1997, Texas Instruments Incorporated
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