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SN54ALS244C, SN54AS244, SN74ALS244C, SN74AS244A
OCTAL BUFFERS AND LINE DRIVERS
WITH 3-STATE OUTPUTS
SDAS142B – JULY 1987 – REVISED DECEMBER 1994
•
•
•
3-State Outputs Drive Bus Lines or Buffer
Memory Address Registers
pnp Inputs Reduce dc Loading
Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Standard Plastic (N)
and Ceramic (J) 300-mil DIPs
SN54ALS244C, SN54AS244 . . . J PACKAGE
SN74ALS244C, SN74AS244A . . . DW OR N PACKAGE
(TOP VIEW)
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. With the
′ALS240A, ′ALS241C,
′AS240A,
SN54AS241, and SN74AS241A, these
devices provide the choice of selected
combinations of inverting outputs, symmetrical
active-low output-enable (OE) inputs, and
complementary OE and OE inputs.
The -1 version of SN74ALS244C is identical to the
standard version, except that the recommended
maximum I
OL
of the -1 version is 48 mA. There is
no -1 version of the SN54ALS244C.
The SN54ALS244C and SN54AS244 are
characterized for operation over the full military
temperature range of – 55°C to 125°C. The
SN74ALS244C
and
SN74AS244A
are
characterized for operation from 0°C to 70°C.
FUNCTION TABLE
(each buffer)
INPUTS
OE
L
L
H
A
H
L
X
OUTPUT
Y
H
L
Z
1OE
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
2OE
1Y1
2A4
1Y2
2A3
1Y3
2A2
1Y4
2A1
SN54ALS244C, SN54AS244 . . . FK PACKAGE
(TOP VIEW)
2Y4
1A1
1OE
V
CC
1A2
2Y3
1A3
2Y2
1A4
4
5
6
7
8
3 2 1 20 19
18
17
16
15
14
9 10 11 12 13
2OE
1Y1
2A4
1Y2
2A3
1Y3
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.
Copyright
©
1994, Texas Instruments Incorporated
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
2Y1
GND
2A1
1Y4
2A2
1
SN54ALS244C, SN54AS244, SN74ALS244C, SN74AS244A
OCTAL BUFFERS AND LINE DRIVERS
WITH 3-STATE OUTPUTS
SDAS142B – JULY 1987 – REVISED DECEMBER 1994
logic symbol
†
1OE
1
EN
18
16
14
12
logic diagram (positive logic)
1OE
1
1A1
1A2
1A3
1A4
2
4
6
8
1Y1
1Y2
1Y3
1Y4
1A1
2
18
1Y1
1A2
4
16
1Y2
1A3
2OE
19
EN
1A4
2A1
2A2
2A3
2A4
11
13
15
17
9
7
5
3
2Y1
2Y2
2Y3
2Y4
2A1
2OE
6
14
1Y3
8
12
1Y4
19
11
9
† This symbol is in accordance with ANSI/IEEE Std 91-1984 and
IEC Publication 617-12.
2Y1
2A2
13
7
2Y2
2A3
15
5
2Y3
2A4
17
3
2Y4
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
: SN54ALS244C . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C
SN74ALS244C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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.
2
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
SN54ALS244C, SN54AS244, SN74ALS244C, SN74AS244A
OCTAL BUFFERS AND LINE DRIVERS
WITH 3-STATE OUTPUTS
SDAS142B – JULY 1987 – REVISED DECEMBER 1994
recommended operating conditions
SN54ALS244C
MIN
VCC
VIH
VIL
IOH
IOL
Supply voltage
High-level input voltage
Low-level
Low level input voltage
High-level output current
Low level output current
Low-level
– 55
4.5
2
0.8†
0.7‡
– 12
12
125
0
NOM
5
MAX
5.5
SN74ALS244C
MIN
4.5
2
0.8
– 15
24
48§
70
NOM
5
MAX
5.5
UNIT
V
V
V
mA
mA
°C
TA
Operating free-air temperature
† Applies over temperature range – 55°C to 70°C
‡ Applies over temperature range 70°C to 125°C
§ Applies only to the -1 version and only if VCC is between 4.75 V and 5.25 V
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
VCC = 4.5 V,
VCC = 4 5 V to 5 5 V
4.5
5.5
VOH
VCC = 4 5 V
4.5
TEST CONDITIONS
II = – 18 mA
IOH = – 0.4 mA
IOH = – 3 mA
IOH = – 12 mA
IOH = – 15 mA
IOL = 12 mA
IOL = 24 mA
IOL = 48 mA (-1 version)
VO = 2.7 V
VO = 0.4 V
VI = 7 V
VI = 2.7 V
VI = 0.4 V
VO = 2.25 V
Outputs high
ICC
VCC = 5.5 V
Outputs low
Outputs disabled
– 20
9
15
17
20
– 20
0.1
20
– 0.1
– 112
15
24
27
– 30
9
15
17
SN54ALS244C
MIN TYP¶
MAX
– 1.5
VCC – 2
2.4
2
2
0.25
0.4
0.25
0.35
0.35
0.4
0.5
0.5
20
– 20
0.1
20
– 0.1
– 112
17
24
27
mA
µA
µA
mA
µA
mA
mA
V
3.2
VCC – 2
2.4
3.2
SN74ALS244C
MIN TYP¶
MAX
– 1.5
UNIT
V
V
VOL
IOZH
IOZL
II
IIH
IIL
IO#
VCC = 4.5 V
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
VCC = 5.5 V,
¶ 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.
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
3
SN54ALS244C, SN54AS244, SN74ALS244C, SN74AS244A
OCTAL BUFFERS AND LINE DRIVERS
WITH 3-STATE OUTPUTS
SDAS142B – JULY 1987 – REVISED DECEMBER 1994
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500
Ω
,
R2 = 500
Ω
,
TA = MIN to MAX†
SN54ALS244C
MIN
tPLH
tPHL
tPZH
tPZL
tPHZ
tPLZ
A
1
Y
Y
Y
3
1
OE
OE
1
2
1
MAX
16
12
26
24
10
26
SN74ALS244C
MIN
2
3
3
3
2
1
MAX
10
10
20
20
10
13
ns
ns
ns
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
UNIT
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
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
: SN54AS244 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C
SN74AS244A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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
SN54AS244
MIN
VCC
VIH
VIL
IOH
IOL
TA
Supply voltage
High-level input voltage
Low-level input voltage
High-level output current
Low-level output current
Operating free-air temperature
– 55
4.5
2
0.8
– 12
48
125
0
NOM
5
MAX
5.5
SN74AS244A
MIN
4.5
2
0.8
– 15
64
70
NOM
5
MAX
5.5
UNIT
V
V
V
mA
mA
°C
4
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
嵌入式系统
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