1999 Fairchild Semiconductor Corporation
DS005365
www.fairchildsemi.com
February 1984
Revised July 1999
MM74HCT240
MM74HCT244 Inver
ti
ng O
c
t
a
l
3-
ST
A
T
E Buff
er
Oct
a
l 3-ST
A
T
E
Buf
f
er
MM74HCT240 MM74HCT244
Inverting Octal 3-STATE Buffer Octal 3-STATE Buffer
General Description
The MM74HCT240 and MM74HCT244 3-STATE buffers
utilize advanced silicon-gate CMOS technology and are
general purpose high speed inverting and non-inverting
buffers. They possess high drive current outputs which
enable high speed operation even when driving large bus
capacitances. These circuits achieve speeds comparable
to low power Schottky devices, while retaining the low
power consumption of CMOS. All three devices are TTL
input compatible and have a fanout of 15 LS-TTL equiva-
lent inputs.
MM74HCT devices are intended to interface between TTL
and NMOS components and standard CMOS devices.
These parts are also plug-in replacements for LS-TTL
devices and can be used to reduce power consumption in
existing designs.
The MM74HCT240 is an inverting buffer and the
MM74HCT244 is a non-inverting buffer. Each device has
two active low enables (1G and 2G), and each enable inde-
pendently controls 4 buffers.
All inputs are protected from damage due to static dis-
charge by diodes to V
CC
and Ground.
Features
s
TTL input compatible
s
Typical propagation delay: 14 ns
s
3-STATE outputs for connection to system buses
s
Low quiescent current: 80
A
s
High output drive current: 6 mA (min)
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter "X" to the ordering code.
Connection Diagrams
Pin Assignments for DIP, SOIC, SOP and TSSOP
Top View
MM74HCT240
Top View
MM74HCT244
Order Number
Package Number
Package Description
MM74HCT240WM
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
MM74HCT240SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
MM74HCT240MTC
MTC20
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
MM74HCT240N
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
MM74HCT244WM
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
MM74HCT244SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
MM74HCT244MTC
MTC20
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
MM74HCT244N
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
3
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MM74HCT240
MM74HCT244
Absolute Maximum Ratings
(Note 1)
(Note 2)
Recommended Operating
Conditions
Note 1: Absolute Maximum Ratings are those values beyond which dam-
age to the device may occur.
Note 2: Unless otherwise specified all voltages are referenced to ground.
Note 3: Power Dissipation temperature derating -- plastic "N" package:
-
12 mW/
C from 65
C to 85
C.
DC Electrical Characteristics
V
CC
=
5V
10% (unless otherwise specified)
Note 4: Measured per input. All other inputs at V
CC
or GND.
Supply Voltage (V
CC
)
-
0.5 to
+
7.0V
DC Input Voltage (V
IN
)
-
1.5 to V
CC
+
1.5V
DC Output Voltage (V
OUT
)
-
0.5 to V
CC
+
0.5V
Clamp Diode Current (I
IK
, I
OK
)
20 mA
DC Output Current, per pin (I
OUT
)
35 mA
DC V
CC
or GND Current, per pin (I
CC
)
70 mA
Storage Temperature Range (T
STG
)
-
65
C to
+
150
C
Power Dissipation (P
D
)
(Note 3)
600 mW
S.O. Package only
500 mW
Lead Temperature (T
L
)
(Soldering 10 seconds)
260
C
Min
Max
Units
Supply Voltage (V
CC
)
4.5
5.5
V
DC Input or Output Voltage
0
V
CC
V
(V
IN
, V
OUT
)
Operating Temperature Range (T
A
)
-
40
+
85
C
Input Rise or Fall Times
(t
r
, t
f
)
500
ns
Symbol
Parameter
Conditions
T
A
=
25
C
T
A
=
-
40 to 85
C T
A
=
-
55
to 125
C
Units
Typ
Guaranteed Limits
V
IH
Minimum HIGH Level
2.0
2.0
2.0
V
Input Voltage
V
IL
Maximum LOW Level
0.8
0.8
0.8
V
Input Voltage
V
OH
Minimum HIGH Level
V
IN-EE
=
V
IH
or V
IL
Output Voltage
|I
OUT
|
=
20
A
V
CC
V
CC
-
0.1
V
CC
-
0.1
V
CC
-
0.1
V
|I
OUT
|
=
6.0 mA, V
CC
=
4.5V
4.2
3.98
3.84
3.7
V
|I
OUT
|
=
7.2 mA, V
CC
=
5.5V
5.2
4.98
4.84
4.7
V
V
OL
Maximum LOW Level
V
IN
=
V
IH
or V
IL
Voltage
|I
OUT
|
=
20
A
0
0.1
0.1
0.1
V
|I
OUT
|
=
6.0 mA, V
CC
=
4.5V
0.2
0.26
0.33
0.4
V
|I
OUT
|
=
7.2 mA, V
CC
=
5.5V
0.2
0.26
0.33
0.4
V
I
IN
Maximum Input
V
IN
=
V
CC
or GND,
0.05
0.5
1.0
A
Current
V
IH
or V
IL
I
OZ
Maximum 3-STATE
V
OUT
=
V
CC
or GND
0.25
2.5
10
A
Output Leakage
G
=
V
IH
Current
G
=
V
IL
I
CC
Maximum Quiescent
V
IN
=
V
CC
or GND
4.0
40
160
A
Supply Current
I
OUT
=
0
A
V
IN
=
2.4V or 0.5V (Note 4)
0.6
1.0
1.3
1.5
mA
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4
MM
74
H
C
T2
40
MM
74HCT244
AC Electrical Characteristics
MM74HCT240, MM74HCT244 V
CC
=
5.0V, t
r
=
t
f
=
6 ns, T
A
=
25
C (unless otherwise specified)
AC Electrical Characteristics
MM74HCT240, MM74HCT244 V
CC
=
5.0V
10%, t
r
=
t
f
=
6 ns (unless otherwise specified)
Note 5: C
PD
determines the no load dynamic power consumption, P
D
=
C
PD
V
CC
2 f
+
I
CC
V
CC
, and the no load dynamic current consumption,
I
S
=
C
PD
V
CC
f
+
I
CC
.
Symbol
Parameter
Conditions
Typ
Guaranteed
Units
Limits
t
PHL
, t
PLH
Maximum Output
C
L
=
45 pF
14
18
ns
Propagation Delay
t
PZL
, t
PZH
Maximum Output
C
L
=
45 pF
20
30
ns
Enable Time
R
L
=
1 k
t
PLZ
, t
PHZ
Maximum Output
C
L
=
5 pF
16
25
ns
Disable Time
R
L
=
1 k
Symbol
Parameter
Conditions
T
A
=
25
C
T
A
=
-
40 to 85
C T
A
=
-
55
to 125
C
Units
Typ
Guaranteed Limits
t
PHL
, t
PLH
Maximum Output
C
L
=
50 pF
14
20
25
30
ns
Propagation Delay
C
L
=
150 pF
20
28
35
42
ns
t
PZH
, t
PZL
Maximum Output
R
L
=
1 k
C
L
=
50 pF
21
30
38
45
ns
Enable Time
C
L
=
150 pF
26
42
53
63
ns
t
PHZ
, t
PLZ
Maximum Output
R
L
=
1 k
16
25
32
38
ns
Disable Time
C
L
=
50 pF
t
THL
, t
TLH
Maximum Output
C
L
=
50 pF
6
12
15
18
ns
Rise and Fall Time
C
IN
Maximum Input
10
15
15
15
pF
Capacitance
C
OUT
Maximum Output
15
20
20
20
pF
Capacitance
C
PD
Power Dissipation
(per buffer)
Capacitance (Note 5)
G
=
V
CC
, G
=
GND
5
pF
G
=
GND, G
=
V
CC
90
pF
5
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MM74HCT240
MM74HCT244
Physical Dimensions
inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Number M20B
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
Package Number M20D
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