Texas Instruments SN54AS286J, SN74AS286N, SN74AS286D, SN74AS286DR, SNJ54AS286FK Datasheet
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SN54AS286, SN74AS286
9-BIT PARITY GENERATORS/CHECKERS
WITH BUS-DRIVER PARITY I/O PORT
SDAS050B – DECEMBER 1983 – REVISED DECEMBER 1994
Copyright 1994, Texas Instruments Incorporated
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
• Generate Either Odd or Even Parity for
Nine Data Lines
• Cascadable for n-Bit Parity
• Direct Bus Connection for Parity
Generation or Checking by Using the
Parity I/O Port
• Glitch-Free Bus During Power Up/Down
• Package Options Include Plastic
Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs
description
The SN54AS286 and SN74AS286 universal 9-bit
parity generators/checkers feature a local output
for parity checking and a 48-mA bus-driving
parity input/output (I/O) port for parity
generation/checking. The word-length capability
is easily expanded by cascading.
The transmit (XMIT
) control input is implemented
specifically to accommodate cascading. When
XMIT
is low, the parity tree is disabled and
PARITY ERROR remains at a high logic level
regardless of the input levels. When XMIT
is high,
the parity tree is enabled. PARITY ERROR
indicates a parity error when either an even
number of inputs (A–I) are high and PARITY I/O
is forced to a low logic level, or when an odd
number of inputs are high and PARITY I/O is
forced to a high logic level.
The I/O control circuitry was designed so that the I/O port remains in the high-impedance state during power up
or power down to prevent bus glitches.
The SN54AS286 is characterized for operation over the full military temperature range of –55°C to 125°C. The
SN74AS286 is characterized for operation from 0°C to 70°C.
FUNCTION TABLE
NUMBER OF INPUTS
(A–I) THAT
ARE HIGH
XMIT
PARITY
I/O
PARITY
ERROR
0, 2, 4, 6, 8 l H H
1, 3, 5, 7, 9 l L H
h h H
0, 2, 4, 6, 8
h l L
h h L
1, 3, 5, 7, 9
h l H
h = high input level l = low input level
H = high output level L = low output level
SN54AS286 ...J PACKAGE
SN74AS286 ...D OR N PACKAGE
(TOP VIEW)
SN54AS286 . . . FK PACKAGE
(TOP VIEW)
3212019
910111213
4
5
6
7
8
18
17
16
15
14
E
NC
D
NC
C
XMIT
NC
I
NC
PARITY ERROR
HGNC
A
B
V
F
PARITY I/O
GND
NC
CC
NC – No internal connection
1
2
3
4
5
6
7
14
13
12
11
10
9
8
G
H
XMIT
I
PARITY ERROR
PARITY I/O
GND
V
CC
F
E
D
C
B
A
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.
SN54AS286, SN74AS286
9-BIT PARITY GENERATORS/CHECKERS
WITH BUS-DRIVER PARITY I/O PORT
SDAS050B – DECEMBER 1983 – REVISED DECEMBER 1994
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
logic symbol
†
2k
8
A
13
F
1
G
2
H
4
I
9
B
10
C
11
D
12
E
EN1
3
PARITY I/O
6
N2
PARITY ERROR
5
XMIT
2, 1
1
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
Pin numbers shown are for the D, J, and N packages.
logic diagram (positive logic)
PARITY
ERROR
5
8
9
10
11
12
13
1
2
4
6
3
A
B
C
D
E
F
G
H
I
PARITY I/O
XMIT
Pin numbers shown are for the D, J, and N packages.
SN54AS286, SN74AS286
9-BIT PARITY GENERATORS/CHECKERS
WITH BUS-DRIVER PARITY I/O PORT
SDAS050B – DECEMBER 1983 – REVISED DECEMBER 1994
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage, V
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
I
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage applied to a disabled 3-state output 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
: SN54AS286 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74AS286 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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.
recommended operating conditions
SN54AS286 SN74AS286
MIN NOM MAX MIN NOM MAX
UNIT
V
CC
Supply voltage 4.5 5 5.5 4.5 5 5.5 V
V
IH
High-level input voltage 2 2 V
V
IL
Low-level input voltage 0.8 0.8 V
p
PARITY ERROR –2 –2
IOHHigh-level output current
PARITY I/O –12 –15
mA
p
PARITY ERROR 20 20
IOLLow-level output current
PARITY I/O 32 48
mA
T
A
Operating free-air temperature –55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54AS286 SN74AS286
PARAMETER
TEST CONDITIONS
MIN TYP‡MAX MIN TYP‡MAX
UNIT
V
IK
VCC = 4.5 V, II = –18 mA –1.2 –1.2 V
All outputs VCC = 4.5 V to 5.5 V, IOH = –2 mA VCC –2 VCC –2
IOH = –3 mA 2.4 2.9 2.4 3
V
OH
PARITY I/O VCC = 4.5 V
IOH = –12 mA 2.4
V
IOH = –15 mA 2.4
PARITY ERROR IOL = 20 mA 0.35 0.5 0.35 0.5
V
OL
VCC = 4.5 V
IOL = 32 mA 0.5
V
PARITY I/O
IOL = 48 mA 0.5
PARITY I/O
VI = 5.5 V 0.1 0.1
I
I
All other inputs
V
CC
= 5.5
V
VI = 7 V 0.1 0.1
mA
PARITY I/O
§
50 50
I
IH
All other inputs
V
CC
=
5.5 V
,
V
I
=
2.7 V
20 20
µ
A
PARITY I/O
§
–0.5 –0.5
I
IL
All other inputs
V
CC
= 5.5 V,
V
I
= 0.4
V
–0.5 –0.5
mA
I
O
¶
VCC = 5.5 V, VO = 2.25 V –30 –112 –30 –112 mA
Transmit
30 43 30 43
I
CC
Receive
V
CC
= 5.5
V
35 50 35 50
mA
‡
All typical values are at VCC = 5 V, TA = 25°C.
§
For I/O ports, the parameters IIH and IIL include the off-state output current.
¶
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.
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