1/9
February 2002
s
5V TOLERANT INPUTS
s
HIGH SPEED: t
PD
= 5.9ns (MAX.) at V
CC
= 3V
s
POWER DOWN PROTECTION ON INPUTS
AND OUTPUTS
s
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24mA (MIN) at V
CC
= 3V
s
PCI BUS LEVELS GUARANTEED AT 24 mA
s
BALANCED PROPAGATION DELAYS:
t
PLH
t
PHL
s
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 1.65V to 3.6V (1.2V Data
Retention)
s
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 244
s
LATCH-UP PERFORMANCE EXCEEDS
500mA (JESD 17)
s
ESD PERFORMANCE:
HBM > 2000V (MIL STD 883 method 3015);
MM > 200V
DESCRIPTION
The 74LVC244A is a low voltage CMOS OCTAL
BUS BUFFER (3-STATE) fabricated with
sub-micron silicon gate and double-layer metal
wiring C
2
MOS technology. It is ideal for 1.65 to 3.6
V
CC
operations and low power and low noise
applications.
It can be interfaced to 5V signal environment for
inputs in mixed 3.3/5V system.
G control output governs four BUS BUFFERs.
This device is designed to be used with 3 state
memory address drivers, etc.
It has more speed performance at 3.3V than 5V
AC/ACT family, combined with a lower power
consumption.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
74LVC244A
LOW VOLTAGE CMOS QUAD BUS BUFFERS (3-STATE)
HIGH PERFORMANCE
.
PIN CONNECTION AND IEC LOGIC SYMBOLS
ORDER CODES
PACKAGE
TUBE
T & R
SOP
74LVC244AM
74LVC244AMTR
TSSOP
74LVC244ATTR
TSSOP
SOP
74LVC244A
2/9
INPUT AND OUTPUT EQUIVALENT CIRCUIT
PIN DESCRIPTION
TRUTH TABLE
X : Don't care
Z : High Impedance
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) I
O
absolute maximum rating must be observed
2) V
O
< GND
PIN No
SYMBOL
NAME AND FUNCTION
1
1G
Output Enable Input
2, 4, 6, 8
1A1 to 1A4
Data Inputs
9, 7, 5, 3
2Y1 to 2Y4
Data Outputs
11, 13, 15,
17
2A1 to 2A4
Data Inputs
18, 16, 14,
12
1Y1 to 1Y4
Data Outputs
19
2G
Output Enable Input
10
GND
Ground (0V)
20
V
CC
Positive Supply Voltage
INPUTS
OUTPUT
G
An
Yn
L
L
L
L
H
H
H
X
Z
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage
-0.5 to +7.0
V
V
I
DC Input Voltage
-0.5 to +7.0
V
V
O
DC Output Voltage (High Impedance or V
CC
= 0V)
-0.5 to +7.0
V
V
O
DC Output Voltage (High or Low State) (note 1)
-0.5 to V
CC
+ 0.5
V
I
IK
DC Input Diode Current
- 50
mA
I
OK
DC Output Diode Current (note 2)
- 50
mA
I
O
DC Output Current
50
mA
I
CC
or I
GND
DC V
CC
or Ground Current per Supply Pin
100
mA
T
stg
Storage Temperature
-65 to +150
C
T
L
Lead Temperature (10 sec)
300
C
74LVC244A
3/9
RECOMMENDED OPERATING CONDITIONS
1) Truth Table guaranteed: 1.2V to 3.6V
2) V
IN
from 0.8V to 2V at V
CC
= 3.0V
DC SPECIFICATIONS
Symbol
Parameter
Value
Unit
V
CC
Supply Voltage (note 1)
1.65 to 3.6
V
V
I
Input Voltage
0 to 5.5
V
V
O
Output Voltage (High Impedance or V
CC
= 0V)
0 to 5.5
V
V
O
Output Voltage (High or Low State)
0 to V
CC
V
I
OH
, I
OL
High or Low Level Output Current (V
CC
= 3.0 to 3.6V)
24
mA
I
OH
, I
OL
High or Low Level Output Current (V
CC
= 2.7 to 3.0V)
12
mA
I
OH
, I
OL
High or Low Level Output Current (V
CC
= 2.3 to 2.7V)
8
mA
I
OH
, I
OL
High or Low Level Output Current (V
CC
= 1.65 to 2.3V)
4
mA
T
op
Operating Temperature
-55 to 125
C
dt/dv
Input Rise and Fall Time (note 2)
0 to 10
ns/V
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
-40 to 85 C
-55 to 125 C
Min.
Max.
Min.
Max.
V
IH
High Level Input
Voltage
1.65 to 1.95
0.65V
CC
0.65V
CC
V
2.3 to 2.7
1.7
1.7
2.7 to 3.6
2
2
V
IL
Low Level Input
Voltage
1.65 to 1.95
0.35V
CC
0.35V
CC
V
2.3 to 2.7
0.7
0.7
2.7 to 3.6
0.8
0.8
V
OH
High Level Output
Voltage
1.65 to 3.6
I
O
=-100
A
V
CC
-0.2
V
CC
-0.2
V
1.65
I
O
=-4 mA
1.2
1.2
2.3
I
O
=-8 mA
1.7
1.7
2.7
I
O
=-12 mA
2.2
2.2
3.0
I
O
=-18 mA
2.4
2.4
3.0
I
O
=-24 mA
2.2
2.2
V
OL
Low Level Output
Voltage
1.65 to 3.6
I
O
=100
A
0.2
0.2
V
1.65
I
O
=4 mA
0.45
0.45
2.3
I
O
=8 mA
0.7
0.7
2.7
I
O
=12 mA
0.4
0.4
3.0
I
O
=24 mA
0.55
0.55
I
I
Input Leakage
Current
3.6
V
I
= 0 to 5.5V
5
5
A
I
off
Power Off Leakage
Current
0
V
I
or V
O
= 5.5V
10
10
A
I
OZ
High Impedance
Output Leakage
Current
3.6
V
I
= V
IH
orV
IL
V
O
= 0 to 5.5V
5
5
A
I
CC
Quiescent Supply
Current
3.6
V
I
= V
CC
or GND
10
10
A
V
I
or V
O
= 3.6 to
5.5V
10
10
I
CC
I
CC
incr. per Input
2.7 to 3.6
V
IH
= V
CC
-0.6V
500
500
A
74LVC244A
4/9
DYNAMIC SWITCHING CHARACTERISTICS
1) Number of output defined as "n". Measured with "n-1" outputs switching from HIGH to LOW or LOW to HIGH. The remaining output is
measured in the LOW state.
AC ELECTRICAL CHARACTERISTICS
1) Skew is defined as the absolute value of the difference between the actual propagation delay for any two outputs of the same device switch-
ing in the same direction, either HIGH or LOW (t
OSLH
= | t
PLHm
- t
PLHn
|, t
OSHL
= | t
PHLm
- t
PHLn
|
2) Parameter guaranteed by design
CAPACITIVE CHARACTERISTICS
1) C
PD
is defined as the value of the IC's internal equivalent capacitance which is calculated from the operating current consumption without
load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I
CC(opr)
= C
PD
x V
CC
x f
IN
+ I
CC
/n (per circuit)
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25 C
Min.
Typ.
Max.
V
OLP
Dynamic Low Level Quiet
Output (note 1)
3.3
C
L
= 50pF
V
IL
= 0V, V
IH
= 3.3V
0.8
V
V
OLV
-0.8
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
C
L
(pF)
R
L
(
)
t
s
= t
r
(ns)
-40 to 85 C
-55 to 125 C
Min.
Max.
Min.
Max.
t
PLH
t
PHL
Propagation Delay
Time
1.65 to 1.95
30
1000
2.0
9.0
12
ns
2.3 to 2.7
30
500
2.0
7.9
10.5
2.7
50
500
2.5
1.5
6.9
8.3
3.0 to 3.6
50
500
2.5
1
5.9
7.1
t
PZL
t
PZH
Output Enable Time
1.65 to 1.95
30
1000
2.0
11
14.3
ns
2.3 to 2.7
30
500
2.0
9.6
12.5
2.7
50
500
2.5
1
8.6
10.3
3.0 to 3.6
50
500
2.5
1
7.6
9.1
t
PLZ
t
PHZ
Output Disable Time 1.65 to 1.95
30
1000
2.0
9.0
11.7
ns
2.3 to 2.7
30
500
2.0
7.8
10.1
2.7
50
500
2.5
2
6.8
8.2
3.0 to 3.6
50
500
2.5
2
6.5
7.8
t
OSLH
t
OSHL
Output To Output
Skew Time (note1,
2)
2.7 to 3.6
1
1
ns
Symbol
Parameter
Test Condition
Value
Unit
V
CC
(V)
T
A
= 25 C
Min.
Typ.
Max.
C
IN
Input Capacitance
4
pF
C
PD
Power Dissipation Capacitance
(note 1)
1.8
f
IN
= 10MHz
28
pF
2.5
30
3.3
34
74LVC244A
5/9
TEST CIRCUIT
R
T
= Z
OUT
of pulse generator (typically 50
)
TEST CIRCUIT AND WAVEFORM SYMBOL VALUE
Symbol
V
CC
1.65 to 1.95V
2.3 to 2.7V
2.7V
3.0 to 3.6V
C
L
30pF
30pF
50pF
50pF
R
L
=
R
1
1000
500
500
500
V
S
2 x V
CC
2 x V
CC
6V
6V
V
IH
V
CC
V
CC
2.7V
2.7V
V
M
V
CC
/2
V
CC
/2
1.5V
1.5V
V
OH
V
CC
V
CC
3.0V
3.0V
V
X
V
OL
+ 0.15V
V
OL
+ 0.15V
V
OL
+ 0.3V
V
OL
+ 0.3V
V
Y
V
OH
- 0.15V
V
OH
- 0.15V
V
OH
- 0.3V
V
OH
- 0.3V
t
r
= t
r
<2.0ns
<2.0ns
<2.5ns
<2.5ns
74LVC244A
6/9
WAVEFORM 1: PROPAGATION DELAYS (f=1MHz; 50% duty cycle)
WAVEFORM 2: OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)
74LVC244A
7/9
DIM.
mm.
inch
MIN.
TYP
MAX.
MIN.
TYP.
MAX.
A
2.65
0.104
a1
0.1
0.2
0.004
0.008
a2
2.45
0.096
b
0.35
0.49
0.014
0.019
b1
0.23
0.32
0.009
0.012
C
0.5
0.020
c1
45 (typ.)
D
12.60
13.00
0.496
0.512
E
10.00
10.65
0.393
0.419
e
1.27
0.050
e3
11.43
0.450
F
7.40
7.60
0.291
0.300
L
0.50
1.27
0.020
0.050
M
0.75
0.029
S
8 (max.)
SO-20 MECHANICAL DATA
PO13L
74LVC244A
8/9
DIM.
mm.
inch
MIN.
TYP
MAX.
MIN.
TYP.
MAX.
A
1.2
0.047
A1
0.05
0.15
0.002
0.004
0.006
A2
0.8
1
1.05
0.031
0.039
0.041
b
0.19
0.30
0.007
0.012
c
0.09
0.20
0.004
0.0089
D
6.4
6.5
6.6
0.252
0.256
0.260
E
6.2
6.4
6.6
0.244
0.252
0.260
E1
4.3
4.4
4.48
0.169
0.173
0.176
e
0.65 BSC
0.0256 BSC
K
0
8
0
8
L
0.45
0.60
0.75
0.018
0.024
0.030
TSSOP20 MECHANICAL DATA
c
E
b
A2
A
E1
D
1
PIN 1 IDENTIFICATION
A1
L
K
e
0087225C
74LVC244A
9/9
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consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of STMicroelectronics.
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