Texas Instruments SN74ALS280D, SN74ALS280DR, SN74ALS280N, SN74ALS280N3, SN74AS280D Datasheet
...
SN74ALS280, SN74AS280
A–I
9-BIT PARITY GENERATORS/CHECKERS
SDAS038C – DECEMBER 1982 – REVISED DECEMBER 1994
• Generate Either Odd or Even Parity for Nine
Data Lines
D OR N PACKAGE
(TOP VIEW)
• Cascadable for n-Bit Parity
G
NC
1
H
2
3
I
4
5
6
7
• Can Be Used to Upgrade Existing Systems
Using MSI Parity Circuits
• Package Options Include Plastic
Small-Outline (D) Packages and Standard
Plastic (N) 300-mil DIPs
description
These universal 9-bit parity generators/checkers
Σ EVEN
Σ ODD
GND
NC – No internal connection
utilize advanced Schottky high-performance
circuitry and feature odd (Σ ODD) and even (Σ EVEN) outputs to facilitate operation of either odd- or even-parity
applications. The word-length capability is easily expanded by cascading.
These devices can be used to upgrade the performance of most systems utilizing the SN74ALS180 and
SN74AS180 parity generators/checkers. Although the SN74ALS280 and SN74AS280 are implemented without
expander inputs, the corresponding function is provided by the availability of an input (I) at terminal 4 and the
absence of any internal connection at terminal 3. This permits the SN74ALS280 and SN74AS280 to be
substituted for the SN74ALS180 and SN74AS180 in existing designs to produce an identical function even if
the devices are mixed with existing SN74ALS180 and SN74AS180 devices.
All SN74AS280 inputs are buffered to lower the drive requirements.
The SN74ALS280 and SN74AS280 are characterized for operation from 0°C to 70°C.
14
13
12
11
10
V
CC
F
E
D
C
B
9
A
8
FUNCTION TABLE
NO. OF INPUTS
THAT ARE HIGH
0, 2, 4, 6, 8 H L
1, 3, 5, 7, 9 L H
logic symbol
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
†
8
A
9
B
10
C
11
D
12
E
13
F
1
G
2
H
4
I
OUTPUTS
Σ EVEN Σ ODD
2k
5
6
Σ EVEN
Σ ODD
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.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 1994, Texas Instruments Incorporated
1
SN74ALS280, SN74AS280
9-BIT PARITY GENERATORS/CHECKERS
SDAS038C – DECEMBER 1982 – REVISED DECEMBER 1994
logic diagram (positive logic)
8
A
9
B
10
C
11
D
12
E
13
F
5
Σ EVEN
6
Σ ODD
1
G
2
H
4
I
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, V
Input voltage, V
Operating free-air temperature range, T
Storage temperature range –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I
: SN74ALS280 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A
†
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74ALS280, SN74AS280
UNIT
PARAMETER
TEST CONDITIONS
UNIT
V
V
VOLV
V
V
(
)
(
)
(INPUT)
(OUTPUT)
An
EVEN
ns
AnyΣ ODD
ns
9-BIT PARITY GENERATORS/CHECKERS
SDAS038C – DECEMBER 1982 – REVISED DECEMBER 1994
recommended operating conditions
SN74ALS280
MIN NOM MAX
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
†
All typical values are at VCC = 5 V, TA = 25°C.
‡
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
Supply voltage 4.5 5 5.5 V
High-level input voltage 2 V
Low-level input voltage 0.8 V
High-level output current –2.6 mA
Low-level output current 24 mA
Operating free-air temperature 0 70 °C
SN74ALS280
MIN TYP†MAX
V
I
I
I
I
I
IK
OH
I
IH
IL
O
CC
‡
VCC = 4.5 V, II = –18 mA –1.5 V
VCC = 4.5 V to 5.5 V, IOH = –0.4 mA VCC –2
VCC = 4.5 V, IOH = –2.6 mA 2.4 3.3
= 4.5
CC
VCC = 5.5 V, VI = 7 V 0.1 mA
VCC = 5.5 V, VI = 2.7 V 20 µA
VCC = 5.5 V, VI = 0.4 V –0.1 mA
VCC = 5.5 V, VO = 2.25 V –30 –112 mA
VCC = 5.5 V 10 16 mA
IOL = 12 mA 0.25 0.4
IOL = 24 mA 0.35 0.5
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
PARAMETER
t
PLH
t
PHL
t
PLH
t
§
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
PHL
FROM
INPUT
y
TO
OUTPUT
Σ
RL = 500 Ω
TA = MIN to MAX
MIN MAX
,
SN74ALS280
3 20
3 20
3 20
4 22
§
UNIT
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
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