SN74ALS620A Datasheet, PDF (1/15 Pages) Texas Instruments – OCTAL BUS TRANSCEIVERS

SN74ALS620A, SN74ALS621A, SN74ALS623A, SN74AS623
OCTAL BUS TRANSCEIVERS
• Local Bus-Latch Capability
• Choice of True or Inverting Logic
• Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic (N) 300-mil DIPs
DEVICE
SN74ALS620A
SN74ALS621A
SN74ALS623A, SN74AS623
OUTPUT
3 state
Open collector
3 state
LOGIC
Inverting
True
True
description
SDAS226A – DECEMBER 1982 – REVISED JANUARY 1995
DW OR N PACKAGE
(TOP VIEW)
OEAB ₁
A1 ₂
A2 3
A3 4
A4 5
A5 6
A6 7
A7 8
A8 9
GND 10
20 ^V_CC
19 ^OEBA
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. The
control-function implementation allows for maximum flexibility in timing.
These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending
upon the logic levels at the output-enable (OEAB and OEBA) inputs.
The output-enable inputs disable the device so that the buses are effectively isolated. The dual-enable
configuration gives the transceivers the capability to store data by simultaneously enabling OEAB and OEBA.
Each output reinforces its input in this transceiver configuration. When both OEAB and OEBA are enabled and
all other data sources to the two sets of bus lines are in the high-impedance state, both sets of bus lines (16 total)
remain at their last states. The 8-bit codes appearing on the two sets of buses are identical for the
SN74ALS621A, SN74ALS623A, and SN74AS623 or complementary for the SN74ALS620A.
The -1 versions of the SN74ALS620A and SN74ALS621A are identical to the standard versions, except that
the recommended maximum I_OL is increased to 48 mA in the -1 versions.
The SN74ALS620A, SN74ALS621A, SN74ALS623A, and SN74AS623 are characterized for operation from
0°C to 70°C.
INPUTS
OEBA OEAB
L
L
H
H
H
L
L
H
FUNCTION TABLE
OPERATION
SN74ALS620A
SN74ALS621A
SN74ALS623A
SN74AS623
B data to A bus
B data to A bus
A data to B bus
Isolation
A data to B bus
Isolation
B data to A bus,
A data to B bus
B data to A bus,
A data to B bus
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 © 1995, Texas Instruments Incorporated
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