Philips N74ALS244A-1D, N74ALS244A-1DB, N74ALS244A-1N, N74ALS244AD, N74ALS244AN Datasheet
74ALS244A/74ALS244A–1
Octal buffer (3–State)
Product specification
IC05 Data Handbook
1991 Feb 08
INTEGRATED CIRCUITS
Philips Semiconductors Product specification
74ALS244A/74ALS244A-1Octal buffer (3-State)
2
1991 Feb 08 853–1277 01670
FEA TURES
•Octal bus interface
•3-State buffer outputs sink 24mA and source 15mA
•The -1 version sinks 48mA
DESCRIPTION
The 74ALS244A is an octal buffer that is ideal for driving bus lines or
buffer memory address registers. The outputs are all capable of
sinking 24mA and sourcing up to 15mA, producing very good
capacitive drive characteristics. The device features two output
enables, OE
a and OEb, each controlling four of the 3-State outputs.
The 74ALS244A-1 sinks 48 mA IOL if the VCC is limited to
5.0V ±0.25V.
TYPE
TYPICAL
PROPAGATION
DELA Y
TYPICAL
SUPPLY CURRENT
(TOTAL)
74ALS244A 4.5ns 17mA
74ALS244A-1 4.5ns 17mA
PIN CONFIGURATION
1
2
3
4
5
6
7
8
9
10 11
12
13
14
15
16
17
18
19
20
V
CC
OEa
Ia0
Yb0
Ia1
Yb1
Ia2
Yb2
Ia3
Yb3
GND
SF00227
OEb
Ya0
Ib0
Ya1
Ib1
Ya2
Ib2
Ya3
Ib3
ORDERING INFORMA TION
ORDER CODE
DESCRIPTION
COMMERCIAL RANGE
V
CC
= 5V ±10%,
T
amb
= 0°C to +70°C
DRAWING
NUMBER
20-pin plastic DIP
74ALS244AN,
74ALS244A-1N
SOT146-1
20-pin plastic SOL
74ALS244AD,
744ALS244A-1D
SOT163-1
20-pin plastic
SSOP Type II
74ALS244ADB,
74ALS244A-1DB
SOT339-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS DESCRIPTION
74ALS (U.L.)
HIGH/LOW
LOAD VALUE
HIGH/LOW
Ian, Ibn Data inputs 1.0/1.0 20µA/0.1mA
OEa, OEb Output Enable inputs (active-Low) 1.0/1.0 20µA/0.1mA
Yan, Ybn Data outputs 750/240 15mA/24mA
Yan, Ybn Data outputs (-1 version) 750/480 15mA/48mA
NOTE: One (1.0) ALS unit load is defined as: 20µA in the High state and 0.1mA in the Low state.
LOGIC SYMBOL
OEa
1
SF00228
2 4 6 8 17 15 13 11
18 16 14 12 3 5 7 9
Ia0 Ia1 Ia2 Ia3 Ib0 Ib1 Ib2 Ib3
Ya0 Ya1 Ya2 Ya3 Yb0 Yb1 Yb2 Yb3
V
CC
= Pin 20
GND = Pin 10
OEb19
IEC/IEEE SYMBOL
1
2D
EN1
EN2
1
2
19
2
4
6
8
17
15
13
11
18
16
14
12
3
5
7
9
SF00229
Philips Semiconductors Product specification
74ALS244A/74ALS244A-1Octal buffer (3-State)
1991 Feb 08
3
LOGIC DIAGRAM
V
CC
= Pin 20
Ia0
SF00230
OEa
Ia3
Ia2
Ia1
2
4
6
8
1
Ya0
Ya1
Ya2
Ya3
18
16
14
12
Ib0
Ib1
Ib2
Ib3
OE
b
17
15
13
11
19
3
5
7
9
Yb0
Yb1
Yb2
Yb3
GND = Pin 10
FUNCTION TABLE
INPUTS OUTPUTS
OEa Ia OEb Ib Ya Yb
L L L L L L
L H L H H H
H X H X Z Z
H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance “off” state
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limit set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free air temperature range.)
SYMBOL
PARAMETER RATING UNIT
V
CC
Supply voltage –0.5 to +7.0 V
V
IN
Input voltage –0.5 to +7.0 V
I
IN
Input current –30 to +5 mA
V
OUT
Voltage applied to output in High output state –0.5 to V
CC
V
pp
p
p
All versions 48 mA
I
OUT
Current applied to output in Low output state
-1 version 96 mA
T
amb
Operating free-air temperature range 0 to +70 °C
T
stg
Storage temperature range –65 to +150 °C
RECOMMENDED OPERATING CONDITIONS
LIMITS
SYMBOL
PARAMETER
MIN NOM MAX
UNIT
V
CC
Supply voltage 4.5 5.0 5.5 V
V
IH
High-level input voltage 2.0 V
V
IL
Low-level input voltage 0.8 V
I
IK
Input clamp current –18 mA
I
OH
High-level output current –15 mA
p
All versions 24 mA
IOLLow-level output current
-1 versions 48
1
mA
T
amb
Operating free-air temperature range
0 +70 °C
NOTES:
1. The 48mA limit applies only under the condition of V
CC
= 5.0V ± 5%.
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