Page 1
74VHC244
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (NON INVERTED)
■ HIGH SPEED: t
■ LOW POWER DISSIPATION:
I
= 4 µA (MAX.) at TA=25°C
CC
■ HIGH NOISE IMMUNITY:
V
= V
NIH
■ POWER DOWN PROTECTION ON INPUTS
■ SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
■ BALANCED PROPAGATION DELAYS:
t
PLH
■ OPERATING VOLTAGE RANGE:
V
CC
■ PIN AND FUNCTION COMPATIBLE WITH
NIL
| = IOL = 8 mA (MIN)
≅ t
PHL
(OPR) = 2V to 5.5V
= 3.9 ns (TYP.) at VCC = 5V
PD
= 28% VCC (MIN.)
74 SERIES 244
■ IMPROVED LATCH-UP IMMUNITY
■ LOW NOISE: V
= 0.9V (MAX.)
OLP
DESCRIPTION
The 74VHC244 is an advanced high-speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with sub-micron silicon gate and
double-layer metal wiring C
G
output enable governs four BUS BUFFERs.
2
MOS technology.
This device is designed to be used with 3 state
memory address drivers, etc.
TSSOPSOP
Table 1: Order Codes
PACKAGE T & R
SOP 74VHC244MTR
TSSOP 74VHC244TTR
Power down protection is provided on all inputs
and 0 to 7V can be accepted on inputs with no
regard to the supply voltage. This device can be
used to interface 5V to 3V.
All inputs and outputs are equipped with
protection circuits against static disc harge, giving
them 2KV ESD immunity and transient excess
voltage.
Figure 1: Pin Connection And IEC Logic Symbols
Rev. 3
1/12November 2004
Page 2
74VHC244
Figure 2: Input Equivalent Circuit Table 2: Pin Description
PIN N° SYMBOL NAME AND FUNCTION
11G
2, 4, 6, 8 1A1 to 1A4 Data Inputs
9, 7, 5, 3 2Y1 to 2Y4 Data Outputs
11, 13, 15, 172A1 to 2A4 Data Inputs
18, 16, 14, 121Y1 to 1Y4 Data Outputs
Output Enable Input
19 2G
Output Enable Input
10 GND Ground (0V)
20 V
CC
Positive Supply Voltage
Table 3: Truth Table
INPUTS OUTPUT
G
An Yn
LLL
LHH
HXZ
X : Don‘t Care
Z : High Impedance
Table 4: Absolute Maximum Ratings
Symbol Parameter Value Unit
V
V
V
I
I
OK
I
or I
I
CC
T
T
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
Supply Voltage
CC
DC Input Voltage
I
DC Output Voltage -0.5 to VCC + 0.5
O
DC Input Diode Current
IK
DC Output Diode Current
DC Output Current
O
DC VCC or Ground Current
GND
Storage Temperature
stg
Lead Temperature (10 sec)
L
-0.5 to +7.0 V
-0.5 to +7.0 V
V
- 20 mA
± 20 mA
± 25 mA
± 75 mA
-65 to +150 °C
300 °C
Table 5: Recommended Operating Conditions
Symbol Parameter Value Unit
V
V
V
T
dt/dv
1) VIN from 30 % t o 70% of V
Supply Voltage
CC
Input Voltage
I
Output Voltage 0 to V
O
Operating Temperature
op
Input Rise and Fall Time (note 1) (V
(V
CC
= 3.3 ± 0.3V)
CC
= 5.0 ± 0.5V)
CC
2 to 5.5 V
0 to 5.5 V
CC
-55 to 125 °C
0 to 100
0 to 20
2/12
V
ns/V
Page 3
Table 6: DC Specifications
Symbol Parameter
V
V
V
High Level Input
IH
Voltage
V
Low Level Input
IL
Voltage
High Level Output
OH
Voltage
Low Level Output
OL
Voltage
I
High Impedance
OZ
Output Leakage
Current
Input Leakage
I
I
Current
I
Quiescent Supply
CC
Current
74VHC244
Test Condition Value
= 25°C
T
V
CC
(V)
A
Min. Typ. Max. Min. Max. Min. Max.
2.0 1.5 1.5 1.5
3.0 to
5.5
0.7V
CC
2.0 0.5 0.5 0.5
3.0 to
5.5
2.0
3.0
4.5
3.0
4.5
2.0
3.0
4.5
3.0
4.5
5.5
0 to
5.5
5.5
IO=-50 µA
I
=-50 µA
O
=-50 µA
I
O
=-4 mA
I
O
=-8 mA
I
O
IO=50 µA
=50 µA
I
O
=50 µA
I
O
=4 mA
I
O
=8 mA
I
O
= VIH or V
V
I
IL
VO = VCC or GND
V
= 5.5V or GND
I
= VCC or GND
V
I
1.9 2.0 1.9 1.9
2.9 3.0 2.9 2.9
4.4 4.5 4.4 4.4
2.58 2.48 2.4
3.94 3.8 3.7
0.3V
0.0 0.1 0.1 0.1
0.0 0.1 0.1 0.1
0.0 0.1 0.1 0.1
±0.25 ± 2.5 ± 2.5 µA
-40 to 85°C -55 to 125°C
CC
0.7V
CC
0.3V
CC
0.7V
CC
0.36 0.44 0.55
0.36 0.44 0.55
± 0.1 ± 1 ± 1 µA
44040µA
0.3V
CC
Unit
V
V
V
V
3/12
Page 4
74VHC244
Table 7: AC Electrical Characteristics (Input tr = tf = 3ns)
Test Condition Value
Symbol Parameter
t
Propagation Delay
PLH
t
t
t
t
t
t
OSLH
t
OSHL
Time
PHL
Output Enable
PZL
Time
PZH
PLZ
Output Disable
PHZ
Time
Output to Output
Skew time (note 1)
V
3.3
3.3
5.0
5.0
3.3
3.3
5.0
5.0
3.3
5.0
3.3
5.0
C
CC
(V)
L
(pF)
(*)
15 5.8 8.4 1.0 10.0 1.0 10.0
(*)
50 8.3 11.9 1.0 13.5 1.0 13.5
(**)
15 3.9 5.5 1.0 6.5 1.0 6.5
(**)
50 5.4 7.5 1.0 8.5 1.0 8.5
(*)
15
(*)
50
(**)
15
(**)
50
(*)
50
(**)
50
(*)
50 1.5 1.5 1.5
(**)
50 1.0 1.0 1.0
R
L
R
L
R
L
R
L
R
L
R
L
= 1KΩ
= 1KΩ
= 1KΩ
= 1KΩ
= 1KΩ
= 1KΩ
T
Min. Typ. Max. Min. Max. Min. Max.
= 25°C
A
-40 to 85°C -55 to 125°C
6.6 10.6 1.0 12.5 1.0 12.5
9.1 14.1 1.0 16.0 1.0 16.0
4.7 7.3 1.0 8.5 1.0 8.5
6.2 9.3 1.0 10.5 1.0 10.5
10.3 14.0 1.0 16.0 1.0 16.0
6.7 9.2 1.0 10.5 1.0 10.5
Unit
ns
ns
ns
ns
(*) Voltage range is 3.3V ± 0.3V
(**) Voltage range is 5.0V ±
Note 1: Parameter guaranteed by design. t
0.5V
soLH
= |t
pLHm
- t
pLHn
|, t
soHL
= |t
pHLm
- t
pHLn
|
Table 8: Capacitive Characteristics
Test Condition Value
= 25°C
Symbol Parameter
T
A
Min. Typ. Max. Min. Max. Min. Max.
C
C
C
Input Capacitance
IN
Output
OUT
Capacitance
Power Dissipation
PD
Capacitance
410 10 10pF
6pF
19 pF
(note 1)
1) CPD 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
-40 to 85°C -55 to 125°C
= CPD x VCC x fIN + ICC/8 (per c ircuit )
CC(opr)
Unit
4/12
Page 5
Table 9: Dynamic Switching Characteristics
Test Condition Value
Symbol Parameter
V
V
Dynamic Low
OLP
Voltage Quiet
OLV
Output (note 1, 2)
V
CC
(V)
5.0
T
A
Min. Typ. Max. Min. Max. Min. Max.
0.6 0.9
-0.9 -0.6
-40 to 85°C -55 to 125°C
= 25°C
Dynamic High
V
IHD
Voltage Input
5.0 3.5 V
= 50 pF
C
L
(note 1, 3)
Dynamic Low
V
ILD
Voltage Input
5.0 1.5 V
(note 1, 3)
1) Worst case package.
2) Max number of outp ut s defined as (n). Data inpu t s are driven 0V to 5.0V, (n-1) outputs switc hi ng and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 5.0V. Inputs under test switching: 5.0V to threshold (V
(V
), f=1MHz.
IHD
ILD
Table 10: Test Circuit
74VHC244
Unit
V
), 0V to thresho l d
TEST SWITCH
t
, t
PLH
PHL
, t
t
PZL
PLZ
t
, t
PZH
PHZ
CL =15/ 50pF or e qui valent (includes jig an d probe capacit ance)
= R1 = 1KΩ or equivalent
R
L
R
= Z
of pulse generator (typically 50Ω)
T
OUT
Open
V
CC
GND
5/12
Page 6
74VHC244
Figure 3: Waveform - Propagation Delays (f=1MHz; 50% duty cycle)
Figure 4: Waveform - Output Enable And Disable Time (f=1MHz; 50% duty cycle)
6/12
Page 7
SO-20 MECHANICAL DATA
74VHC244
DIM.
A 2.35 2.65 0.093 0.104
A1 0.1 0.30 0.004 0.012
B 0.33 0.51 0.013 0.020
C 0.23 0.32 0.009 0.013
D 12.60 13.00 0.496 0.512
E 7.4 7.6 0.291 0.299
e 1.27 0.050
H 10.00 10.65 0.394 0.419
h 0.25 0.75 0.010 0.030
L 0.4 1.27 0.016 0.050
k0° 8° 0° 8°
ddd 0.100 0.004
MIN. TYP MAX. MIN. TYP. MAX.
mm. inch
0016022D
7/12
Page 8
74VHC244
TSSOP20 MECHANICAL DATA
mm. inch
DIM.
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 0.0079
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
K0˚ 8˚0˚ 8˚
L 0.45 0.60 0.75 0.018 0.024 0.030
A2
A
A1
b
e
K
c
L
E
D
E1
PIN 1 IDENTIFICATION
8/12
1
0087225C
Page 9
74VHC244
Tape & Reel SO-20 MECHANICAL
mm. inch
DIM.
MIN. TYP MAX. MIN. TYP. MAX.
A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N 60 2.362
T 30.4 1.197
Ao 10.8 11 0.425 0.433
Bo 13.2 13.4 0.520 0.528
Ko 3.1 3.3 0.122 0.130
Po 3.9 4.1 0.153 0.161
P 11.9 12.1 0.468 0.476
DATA
9/12
Page 10
74VHC244
Tape & Reel TSSOP20 MECHANICAL DATA
mm. inch
DIM.
MIN. TYP MAX. MIN. TYP. MAX.
A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N 60 2.362
T 22.4 0.882
Ao 6.8 7 0.268 0.276
Bo 6.9 7.1 0.272 0.280
Ko 1.7 1.9 0.067 0.075
Po 3.9 4.1 0.153 0.161
P 11.9 12.1 0.468 0.476
10/12
Page 11
Table 11: Revision History
Date Revisio n Description of Changes
12-Nov-2004 3 Order Codes Revision - pag. 1.
74VHC244
11/12
Page 12
74VHC244
Information fur nished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of s uch inf ormati on nor for a ny infr ing eme nt o f p atent s or o ther ri ghts of third parties wh ich m ay res ult fr om it s us e. No li cens e i s gr an ted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Speci fications mentioned in this publication are subject
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authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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