74VHC244 Octal Buffer/Line Driver with 3-STATE Outputs
November 1992
Revised April 2005
74VHC244
Octal Buffer/Line Driver with 3-STATE Outputs
General Description
The VHC244 is an advanced high speed CMOS octal bus
buffer fabricated with silicon gate CMOS technology. It
achieves high speed operation similar to equivalent Bipolar
Schottky TTL while maintaining the CMOS low power dissi-
pation. The VHC244 is a non-inverting 3-STATE buffer hav-
ing two active-LOW output enables. These devices are
designed to be used as 3-STATE memory address drivers,
clock drivers, and bus oriented transmitter/receivers.
An input protection circuit ensures that 0V to 7V can be
applied to the input pins without regard to the supply volt-
age. This device can be used to interface 5V to 3V systems
and two supply systems such as battery back up. This cir-
cuit prevents device destruction due to mismatched supply
and input voltages.
Features
s
High Speed: t
PD
3.9ns (typ) at V
CC
V
NIL
5V
s
High noise immunity: V
NIH
s
Low noise: V
OLP
28% V
CC
(min)
s
Power down protection is provided on all inputs
0.6V (typ)
4
P
A (max) @ T
A
25
q
C
s
Low power dissipation: I
CC
s
Pin and function compatible with 74HC244
Ordering Code:
Order Number
74VHC244M
74VHC244SJ
74VHC244MTC
74VHC244N
Package Number
M20B
M20D
MTC20
N20A
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Pb-Free 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Pb-Free package per JEDEC J-STD-020B.
Logic Symbol
IEEE/IEC
Connection Diagram
© 2005 Fairchild Semiconductor Corporation
DS011522
www.fairchildsemi.com
74VHC244
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
CC
)
DC Input Voltage (V
IN
)
DC Output Voltage (V
OUT
)
Input Diode Current (I
IK
)
Output Diode Current (I
OK
)
DC Output Current (I
OUT
)
DC V
CC
/GND Current (I
CC
)
Storage Temperature (T
STG
)
Lead Temperature (T
L
)
(Soldering, 10 seconds)
260
q
C
0.5V to
7.0V
0.5V to
7.0V
0.5V to V
CC
0.5V
20 mA
r
20 mA
r
25 mA
r
75 mA
65
q
C to
150
q
C
Recommended Operating
Conditions
(Note 2)
Supply Voltage (V
CC
)
Input Voltage (V
IN
)
Output Voltage (V
OUT
)
Operating Temperature (T
OPR
)
Input Rise and Fall Time (t
r
, t
f
)
V
CC
V
CC
3.3V
r
0.3V
5.0V
r
0.5V
0 ns/V
a
100 ns/V
0 ns/V
a
20 ns/V
2.0V to 5.5V
0V to
5.5V
0V to V
CC
40
q
C to
85
q
C
Note 1:
Absolute Maximum Ratings are values beyond which the device
may be damaged or have its useful life impaired. The databook specifica-
tions should be met, without exception, to ensure that the system design is
reliable over its power supply, temperature, and output/input loading vari-
ables. Fairchild does not recommend operation outside databook specifica-
tions.
Note 2:
Unused inputs must be held HIGH or LOW. They may not float.
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
OH
Parameter
HIGH Level
Input Voltage
LOW Level
Input Voltage
HIGH Level
Output Voltage
V
CC
(V)
2.0
3.0
5.5
2.0
3.0
5.5
2.0
3.0
4.5
3.0
4.5
V
OL
LOW Level
Output Voltage
2.0
3.0
4.5
3.0
4.5
I
OZ
I
IN
I
CC
3-STATE Output
Off-State Current
Input Leakage Current
Quiescent Supply Current
0
5.5
5.5
5.5
1.9
2.9
4.4
2.58
3.94
0.0
0.0
0.0
0.1
0.1
0.1
0.36
0.36
2.0
3.0
4.5
Min
1.5
0.7 V
CC
0.5
0.3 V
CC
1.9
2.9
4.4
2.48
3.80
0.1
0.1
0.1
0.44
0.44
V
I
OL
I
OL
V
IN
V
OUT
V
IN
V
IN
V
IH
or V
IL
V
CC
or GND
5.5V or GND
V
CC
or GND
4 mA
8 mA
V
V
V
IN
I
OH
I
OH
V
IH
I
OL
or V
IL
V
T
A
25
q
C
Typ
Max
T
A
40
q
C to
85
q
C
Max
1.5
Min
0.7 V
CC
Units
V
Conditions
0.5
0.3 V
CC
V
V
IN
V
IH
I
OH
or V
IL
50
P
A
4 mA
8 mA
50
P
A
r
0.25
r
0.1
4.0
r
2.5
r
1.0
40.0
P
A
P
A
P
A
Noise Characteristics
Symbol
V
OLP
(Note 3)
V
OLV
(Note 3)
V
IHD
(Note 3)
V
ILD
(Note 3)
Parameter
Quiet Output Maximum
Dynamic V
OL
Quiet Output Minimum
Dynamic V
OL
Minimum HIGH Level
Dynamic Input Voltage
Maximum HIGH Level
Dynamic Input Voltage
5.0
1.5
V
C
L
50 pF
5.0
3.5
V
C
L
50 pF
5.0
V
CC
(V)
5.0
T
A
Typ
0.6
25
q
C
Limits
0.9
Units
V
V
C
L
C
L
50 pF
50 pF
Conditions
0.6
0.9
Note 3:
Parameter guaranteed by design.
3
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74VHC244
AC Electrical Characteristics
Symbol
t
PLH
t
PHL
Parameter
Propagation Delay
Time
5.0
r
0.5
t
PZL
t
PZH
3-STATE Output
Enable Time
5.0
r
0.5
t
PLZ
t
PHZ
t
OSLH
t
OSHL
C
IN
C
OUT
C
PD
3-STATE Output
Disable Time
Output to Output
Skew
Input Capacitance
Output Capacitance
Power Dissipation Capacitance
|t
PLHmax
t
PLHmin
|; t
OSHL
V
CC
(V)
3.3
r
0.3
Min
T
A
25
q
C
Typ
5.8
8.3
3.9
5.4
6.6
9.1
4.7
6.2
10.3
6.7
Max
8.4
11.9
5.5
7.5
10.6
14.1
7.3
9.3
14.0
9.2
1.5
1.0
4
6
19
|t
PHLmax
t
PHLmin
|.
T
A
40
q
C to
85
q
C
Max
10.0
13.5
6.5
8.5
12.5
16.0
8.5
10.5
16.0
10.5
1.5
1.0
10
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
Min
Units
ns
ns
ns
R
L
ns
ns
ns
pF
pF
pF
R
L
Conditions
C
L
C
L
C
L
C
L
C
L
1 k
:
C
L
C
L
C
L
1 k
:
C
L
C
L
C
L
C
L
15 pF
50 pF
15 pF
50 pF
15 pF
50 pF
15 pF
50 pF
50 pF
50 pF
50 pF
50 pF
3.3
r
0.3
3.3
r
0.3
5.0
r
0.5
3.3
r
0.3
5.0
r
0.5
(Note 4)
V
CC
V
CC
10
Open
5.0V
(Note 5)
Note 4:
Parameter guaranteed by design. t
OSLH
Note 5:
C
PD
is defined as the value of the internal equivalent capacitance which is calculated from the operating current consumption without load. Average
operating current can be obtained by the equation: I
CC
(OPR.) C
PD
* V
CC
* f
IN
I
CC
/8 (per bit).
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