SN54ALS240A, SN54AS240A, SN74ALS240A, SN74AS240A
OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SDAS214E – DECEMBER 1982 – REVISED AUGUST 2002
SN54ALS240A, SN54AS240A . . . J OR W PACKAGE
3-State Outputs Drive Bus Lines or Buffer
Memory Address Registers
SN74ALS240A . . . DB, DW, N, OR NS PACKAGE
SN74AS240A . . . DW OR N PACKAGE
(TOP VIEW)
pnp Inputs Reduce dc Loading
description/ordering information
1OE
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
V
CC
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
2OE
1Y1
2A4
1Y2
2A3
1Y3
These octal buffers/drivers are designed
specifically to improve both the performance and
density of 3-state memory address drivers, clock
drivers, and bus-oriented receivers and
transmitters. When these devices are used with
the ’ALS241, ’AS241A, ’ALS244, and ’AS244A
devices, the circuit designer has a choice of
selected combinations of inverting and
noninverting outputs, symmetrical active-low
output-enable (OE) inputs, and complementary
OE and OE inputs. These devices feature high
fan-out and improved fan-in.
13 2A2
12 1Y4
11
2A1
SN54ALS240A, SN54AS240A . . . FK PACKAGE
(TOP VIEW)
The -1 version of SN74ALS240A is identical to the
standard version, except that the recommended
3
2
1
20 19
18
1Y1
2A4
1Y2
2A3
1Y3
1A2
2Y3
1A3
2Y2
1A4
maximum I for the -1 version is 48 mA. There is
4
5
6
7
8
OL
no -1 version of the SN54ALS240A.
17
16
15
14
9 10 11 12 13
ORDERING INFORMATION
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
†
PACKAGE
T
A
SN74ALS240AN
SN74ALS240A-1N
SN74AS240AN
SN74ALS240AN
SN74ALS240A-1N
SN74AS240AN
PDIP – N
Tube
Tube
SN74ALS240ADW
ALS240A
ALS240A-1
AS240A
Tape and reel SN74ALS240ADWR
Tube SN74ALS240A-1DW
Tape and reel SN74ALS240A-1DWR
Tube SN74AS240ADW
SOIC – DW
0°C to 70°C
Tape and reel SN74AS240ADWR
SN74ALS240ANSR
Tape and reel
ALS240A
ALS240A-1
G240A
SOP – NS
SN74ALS240A-1NSR
SN74ALS240ADBR
Tape and reel
SSOP – DB
SN74ALS240A-1DBR
G240A-1
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are
available at www.ti.com/sc/package.
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.
Copyright 2002, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
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.
1
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