SN74ALS994 Datasheet, PDF (1/7 Pages) Texas Instruments – 10-BIT D-TYPE TRANSPARENT READ-BACK LATCH

SN74ALS994
10-BIT D-TYPE TRANSPARENT READ-BACK LATCH
SDAS237A – OCTOBER 1984 – REVISED JANUARY 1995
• 3-State I/O-Type Read-Back Inputs
• Bus-Structured Pinout
• True Logic Outputs
• Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic (NT) 300-mil DIPs
description
This 10-bit latch is designed specifically for storing
the contents of the input data bus and providing
the capability of reading back the stored data onto
the input data bus.
The ten latches are transparent D-type latches.
While the latch-enable (LE) input is high, the
Q outputs follow the data (D) inputs.
DW OR NT PACKAGE
(TOP VIEW)
OERB 1
1D 2
2D 3
3D 4
4D 5
5D 6
6D 7
7D 8
8D 9
9D 10
10D 11
GND 12
24 V_CC
23 1Q
22 2Q
21 3Q
20 4Q
19 5Q
18 6Q
17 7Q
16 8Q
15 9Q
14 10Q
13 LE
Read back is provided through the output-enable (OERB) input. When OERB is taken low, the data present at
the output of the data latches passes back onto the input data bus. When OERB is taken high, the output of the
data latches is isolated from the D inputs. OERB does not affect the internal operation of the latches; however,
precautions should be taken to avoid a bus conflict.
The SN74ALS994 is characterized for operation from 0°C to 70°C.
logic symbol^†
1
OERB
EN2
13
LE
C1
2
1D
1D
2
3
2D
4
3D
5
4D
6
5D
7
6D
8
7D
9
8D
10
9D
11
10D
† _{This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.}
23
1Q
22
2Q
21
3Q
20
4Q
19
5Q
18
6Q
17
7Q
16
8Q
15
9Q
14
10Q
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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