
HD74HCT244
Octal Buffers/Line Drivers/Line Receivers
(noninverted 3-state outputs)
Description
The HD74HCT244 is a non-inverting buffer and has two active low enable (1G and 2G). Each enable
independently controls 4 buffers.
This device does not have schmitt trigger inputs.
Features
• LSTTL Output Logic Level Compatibility as well as CMOS Output Compatibility
• High Speed Operation: tpd (A to Y) = 10 ns typ (CL = 50 pF)
• High Output Current: Fanout of 15 LSTTL Loads
• Wide Operating Voltage: VCC = 4.5 to 5.5 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)
Function Table
Inputs Output
G AY
HX Z
LH H
LL L
H : High level
L : Low level
X : Irrelevant
Z : Off (high-impedance) state of a 3-state output

HD74HCT244
Pin Arrangement
1G
1A
1
2
1
20
19
V
2G
CC
Block Diagram
Input A
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
3
4
5
6
7
8
9
10
(Top view)
To three other inverters
18
17
16
15
14
13
12
11
V
CC
1Y
2A4
1Y2
2A3
1Y3
2A2
1Y4
2A1
1
One of 8
inverters
Y
Strobe G
2

HD74HCT244
Absolute Maximum Ratings
Item Symbol Rating Unit
Supply voltage range V
Input voltage V
Output voltage V
DC current drain per pin I
DC current drain per VCC, GND ICC, I
DC input diode current I
DC output diode current I
Power dissipation per package P
CC
IN
OUT
OUT
GND
IK
OK
T
Storage temperature Tstg –65 to +150 °C
DC Characteristics
Ta = –40 to
Ta = 25°C
Item Symbol Min Typ Max Min Max Unit V
Input voltage V
Output voltage V
IH
V
IL
OH
2.0 — — 2.0 — V 4.5 to
— — 0.8 — 0.8 V 4.5 to
4.4 — — 4.4 — V 4.5 Vin = VIH or VILIOH = –20 µA
4.18 — — 4.13 — 4.5 IOH = –6 mA
V
OL
— — 0.1 — 0.1 V 4.5 Vin = VIH or VILIOL = 20 µA
— — 0.26 — 0.33 4.5 IOL = 6 mA
Off-state output
I
OZ
——±0.5 — ±5.0 µA 5.5 Vin = VIH or VIL,
current
Input current Iin — — ±0.1 — ±1.0 µA 5.5 Vin = VCC or GND
Quiescent current I
CC
— — 4.0 — 40 µA 5.5 Vin = VCC or GND, Iout = 0 µA
+85°C Test Conditions
–0.5 to +7.0 V
–0.5 to VCC + 0.5 V
–0.5 to VCC + 0.5 V
±35 mA
±75 mA
±20 mA
±20 mA
500 mW
(V)
CC
5.5
5.5
Vout = V
or GND
CC
3

HD74HCT244
AC Characteristics (CL = 50 pF, Input tr = tf = 6 ns)
Ta = –40 to
Ta = 25°C
Item Symbol Min Typ Max Min Max Unit V
Propagation delay t
time t
Output enable t
time t
Output disable t
time t
Output rise/fall
time
PLH
PHL
ZL
ZH
LZ
HZ
t
TLH
t
THL
— 9 20 — 25 ns 4.5
— 11 20 — 25 4.5
— 13 30 — 38 ns 4.5
— 12 30 — 38 4.5
— 14 30 — 38 ns 4.5
— 17 30 — 38 4.5
— 4 12 — 15 ns 4.5
Input capacitance Cin — 5 10 — 10 pF —
+85°C Test Conditions
(V)
CC
4

24.50
25.40 Max
Unit: mm
1120
6.30
1
0.89
1.27 Max
2.54 ± 0.25
1.30
10
0.48 ± 0.10
7.00 Max
0.51 Min
2.54 Min 5.08 Max
Hitachi Code
JEDEC
EIAJ
Weight
7.62
+ 0.11
0.25
– 0.05
0° – 15°
(reference value)
DP-20N
—
Conforms
1.26 g

20
Unit: mm
12.6
13 Max
11
5.5
1
0.80 Max
1.27
*0.42 ± 0.08
0.40 ± 0.06
*Dimension including the plating thickness
Base material dimension
10
0.12
0.10 ± 0.10
0.15
M
2.20 Max
7.80
0.20 ± 0.04
*0.22 ± 0.05
0.70 ± 0.20
Hitachi Code
JEDEC
EIAJ
Weight
(reference value)
+ 0.20
– 0.30
1.15
0° – 8°
FP-20DA
—
Conforms
0.31 g

20
Unit: mm
12.8
13.2 Max
11
7.50
1
0.935 Max
1.27
*0.42 ± 0.08
0.40 ± 0.06
*Dimension including the plating thickness
Base material dimension
10
0.12
0.20 ± 0.10
0.15
2.65 Max
M
10.40
0.25 ± 0.04
*0.27 ± 0.05
0.70
Hitachi Code
JEDEC
EIAJ
Weight
+ 0.25
– 0.40
1.45
+ 0.57
– 0.30
(reference value)
0° – 8°
FP-20DB
Conforms
—
0.52 g

20 11
110
+0.08
*0.22
–0.07
0.20 ± 0.06
6.50
6.80 Max
0.65 Max
0.65
0.13
Unit: mm
4.40
1.0
M
6.40 ± 0.20
0.10
1.10 Max
*Dimension including the plating thickness
Base material dimension
0.15 ± 0.04
*0.17 ± 0.05
+0.03
–0.04
0.07
0° – 8°
Hitachi Code
JEDEC
EIAJ
(reference value)
Weight
0.50 ± 0.10
TTP-20DA
—
—
0.07 g

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for maximum rating, operating supply voltage range, heat radiation characteristics, installation
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