Datasheet




SDAS040B − DECEMBER 1983 − REVISED JANUARY 1995
Copyright  1995, Texas Instruments Incorporated
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443
• Open-Collector Outputs Drive Bus Lines or
Buffer Memory Address Registers
• Eliminate the Need for 3-State Overlap
Protection
• pnp Inputs Reduce dc Loading
• Open-Collector Versions of ′AS240A and
′AS241
• Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Standard Plastic (N)
and Ceramic (J) 300-mil DIPs
description
These octal buffers and line drivers are designed
specifically to improve the performance and
density of 3-state memory address drivers, clock
drivers, and bus-oriented receivers and
transmitters by eliminating the need for 3-state
overlap protection. The 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.
The SN54AS756 is characterized for operation
over the full military temperature range of −55°C
to 125°C. The SN74AS756 and SN74AS757 are
characterized for operation from 0°C to 70°C.
logic symbols
‡
2
1A1
4
1A2
6
1A3
8
1A4
EN
1
1Y1
18
1Y2
16
1Y3
14
1Y4
12
11
2A1
13
2A2
15
2A3
17
2A4
EN
19
2Y1
9
2Y2
7
2Y3
5
2Y4
3
1OE
2OE
′AS756
2
1A1
4
1A2
6
1A3
8
1A4
EN
1
1Y1
18
1Y2
16
1Y3
14
1Y4
12
11
2A1
13
2A2
15
2A3
17
2A4
EN
19
2OE
2Y1
9
2Y2
7
2Y3
5
2Y4
3
1OE
SN74AS757
‡
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
1OE
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
V
CC
2OE/2OE
†
1Y1
2A4
1Y2
2A3
1Y3
2A2
1Y4
2A1
SN54AS756 ...J PACKAGE
SN74AS756, SN74AS757 . . . DW OR N PACKAGE
(TOP VIEW)
3 2 1 20 19
910111213
4
5
6
7
8
18
17
16
15
14
1Y1
2A4
1Y2
2A3
1Y3
1A2
2Y3
1A3
2Y2
1A4
SN54AS756 . . . FK PACKAGE
(TOP VIEW)
2Y4 1A1 1OE
1Y4 2A2 2OE 2Y1
GND
2A1
V
CC
†
2OE
for ′AS756 or 2OE for SN74AS757
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