UNISONIC TECHNOLOGIES CO., LTD
U74AC244
OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
DESCRIPTION
The
U74AC244
is a octal buffers/drivers with 3-state outputs. It is
organized as two 4-bit buffers/drivers with separate output-enable
(
OE
) inputs. When
OE
is high, the Y outputs are in a
high-impedance state, and the outputs neither load nor drive the bus
lines. When
OE
is low, the device passes noninverted data from
the A inputs to the Y outputs.
The
U74AC244
is designed to improve the performance and
density of 3-state memory address drivers, clock drivers, and
bus-oriented receivers and transmitters.
To ensure the high-impedance state during power up or power
down,
OE
should be tied to V
CC
through a pull-up resistor; the
minimum value of the resistor is determined by the current-sinking
capability of the driver.
CMOS IC
TSSOP-20
FEATURES
* Wide supply voltage range from 2V to 6V
* Max t
pd
of 7 ns from A to Y at 5V
* Low power consumption, I
CC
= 4
μA
(Max.) at 5.5V
* ±24 mA output driver at 5.5V
ORDERING INFORMATION
Ordering Number
Lead Free
U74AC244L-P20-R
U74AC244L- P20-T
Halogen Free
U74AC244G- P20-R
U74AC244G- P20-T
Package
TSSOP-20
TSSOP-20
Packing
Tape Reel
Tube
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Copyright © 2012 Unisonic Technologies Co., Ltd
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QW-R502-784.A
U74AC244
PIN CONFIGURATION
CMOS IC
FUNCTION TABLE
(
each buffer)
INPUTS
OE
A
H
L
X
OUTPUT
Y
H
L
Z
L
L
H
LOGIC SYMBOL
(positive logic)
1OE
1
2OE
18
19
1A1
2
1Y1
2A1
11
9
2Y1
1A2
4
16
1Y2
2A2
13
7
2Y2
1A3
6
14
1Y3
2A3
15
5
2Y3
1A4
8
12
1Y4
2A4
17
3
2Y4
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QW-R502-784.A
U74AC244
ABSOLUTE MAXIMUM RATING
(T
A
=25°C , unless otherwise specified)
PARAMETER
CMOS IC
SYMBOL
TEST CONDITIONS
Supply Voltage
V
CC
-0.5~7
V
Input Voltage
V
IN
-0.5~V
CC
+0.5
V
Output Voltage
V
OUT
-0.5~V
CC
+0.5
V
Input Clamp Current (V
IN
<0, or V
IN
>V
CC
)
I
IK
±20
mA
Output Clamp Current (V
OUT
<0, or V
OUT
>V
CC
)
I
OK
±20
mA
Output Current
I
OUT
±50
mA
V
CC
or GND Current
I
CC
±200
mA
Storage Temperature
T
STG
-65 ~ +150
°C
Notes: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
THERMAL DATA
PARAMETER
Junction to Ambient
SYMBOL
θ
JA
RATING
85
UNIT
°C/W
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Supply Voltage
High-Level Input Voltage
SYMBOL
V
CC
V
IH
TEST CONDITIONS
V
CC
= 3V
V
CC
= 4.5V
V
CC
= 5.5V
V
CC
= 3V
V
CC
= 4.5V
V
CC
= 5.5V
MIN
2
2.1
3.15
3.85
MAX
6
UNIT
V
V
0.9
1.35
1.65
V
CC
V
CC
-12
-24
-24
12
24
24
8
85
Low-Level Input Voltage
Input Voltage
Output Voltage
High-level Output Current
V
IL
V
IN
V
OUT
I
OH
V
V
V
mA
0
0
V
CC
=3V
V
CC
=4.5V
V
CC
=5.5V
V
CC
=3V
V
CC
=4.5V
V
CC
=5.5V
-40
Low-level Output Current
Input Transition Rise or Fall Rate
Operating Temperature
I
OL
Δt/Δv
T
A
mA
ns/V
°C
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QW-R502-784.A
U74AC244
ELECTRICAL CHARACTERISTICS
(T
A
=25°C , unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITIONS
I
OH
= -50
μA,
V
CC
= 3V
I
OH
= -50
μA,
V
CC
= 4.5V
I
OH
= -50
μA,
V
CC
= 5.5V
I
OH
= -12 mA, V
CC
= 3V
I
OH
= -24 mA, V
CC
= 4.5V
I
OH
= -24 mA, V
CC
= 5.5V
I
OL
= 50
μA,
V
CC
= 3V
I
OL
= 50
μA,
V
CC
= 4.5V
I
OL
= 50
μA,
V
CC
= 5.5V
I
OL
= 12 mA, V
CC
= 3V
I
OL
= 24 mA, V
CC
= 4.5V
I
OL
= 24 mA, V
CC
= 5.5V
V
IN
= V
CC
or GND, V
CC
= 5.5V
V
O
= V
CC
or GND, V
CC
= 5.5V
V
I(OE)
= V
IL
or V
IH
V
IN
= V
CC
or GND, I
OUT
= 0, V
CC
= 5.5V
V
IN
= V
CC
or GND, V
CC
=5V
CMOS IC
High-Level Output Voltage
V
OH
Low-Level Output Voltage
V
OL
MIN TYP MAX UNIT
2.9
4.4
5.4
V
2.56
3.86
4.86
0.1
0.1
0.1
V
0.36
0.36
0.36
±0.1
μA
Input Leakage Current
(A or
OE
inputs)
High-impedance state Current
Quiescent Supply Current
Input Capacitance
I
I(LEAK)
I
OZ
I
CC
C
IN
±0.25
μA
4
2.5
μA
pF
SWITCHING CHARACTERISTICS
PARAMETER
Propagation delay from input A to
output Y, t
pd
SYMBOL
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
TEST CONDITIONS
V
CC
=3.3±0.3V, C
L
=50pF, R
L
=500Ω
V
CC
=5±0.5V, C
L
=50pF, R
L
=500Ω
V
CC
=3.3±0.3V, C
L
=50pF, R
L
=500Ω
V
CC
=5±0.5V, C
L
=50pF, R
L
=500Ω
V
CC
=3.3±0.3V, C
L
=50pF, R
L
=500Ω
V
CC
=5±0.5V, C
L
=50pF, R
L
=500Ω
V
CC
=3.3±0.3V, C
L
=50pF, R
L
=500Ω
V
CC
=5±0.5V, C
L
=50pF, R
L
=500Ω
V
CC
=3.3±0.3V, C
L
=50pF, R
L
=500Ω
V
CC
=5±0.5V, C
L
=50pF, R
L
=500Ω
V
CC
=3.3±0.3V, C
L
=50pF, R
L
=500Ω
V
CC
=5±0.5V, C
L
=50pF, R
L
=500Ω
MIN
2
1.5
2
1.5
2
1.5
2.5
1.5
3
2.5
2.5
2
TYP
6.5
5
6.5
5
6
5
7.5
5.5
7
6.5
7.5
6.5
MAX UNIT
9
ns
7
9
ns
7
10.5 ns
7
10
ns
8
10
ns
9
10.5 ns
9
Propagation delay from input
OE
to
output Y, t
en
Propagation delay from input
OE
to
output Y, t
dis
OPERATING CHARACTERISTICS
PARAMETER
Power dissipation capacitance per
buffer/driver
SYMBOL
C
pd
TEST CONDITIONS
V
CC
= 5V, f=1MHz, C
L
=50pF
TYP UNIT
45
pF
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QW-R502-784.A
U74AC244
TEST CIRCUIT AND WAVEFORMS
CMOS IC
TEST
t
PLH
/t
PHL
t
PLZ
/t
PZL
t
PHZ
/t
PZH
S1
OPEN
V
LOAD
Open
V
CC
3.3V±0.3V
5V±0.5V
Inputs
V
IN
V
CC
V
CC
t
r
, t
f
≤2.5ns
≤2.5ns
V
M
V
CC
/2
V
CC
/2
V
LOAD
2*V
CC
2*V
CC
C
L
50pF
50pF
R
L
500Ω
500Ω
V
Δ
3.3V±0.3V
5V±0.5V
V IN
Input
VM
VM
0V
t PLH
tPHL
V OH
Output
VM
VM
V OL
tPHL
t PLH
V OH
Output
VM
VM
V OL
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QW-R502-784.A
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