SGS Thomson Microelectronics 74VHCT244A Datasheet
74VHCT244A
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (NON INVERTED)
■ HIGH SPEED:t
■ LOW POWERDISSIPATION:
=4 µA(MAX.) at TA=25oC
I
CC
■ COMPATIBLEWITHTTLOUTPUTS:
=2V(MIN),VIL=0.8V(MAX)
V
IH
■ POWERDOWN PROTECTIONON INPUTS&
=3.9ns (TYP.)at VCC=5V
PD
OUTPUTS
■ SYMMETRICALOUTPUTIMPEDANCE:
|I
|=IOL=8mA (MIN)
OH
■ BALANCEDPROPAGATIONDELAYS:
t
≅ t
PLH
PHL
■ OPERATINGVOLTAGERANGE:
(OPR)= 4.5Vto5.5V
V
CC
■ PINANDFUNCTIONCOMPATIBLEWITH
74SERIES244
■ IMPROVEDLATCH-UPIMMUNITY
■ LOWNOISEV
=0.9V(Max.)
OLP
DESCRIPTION
The 74VHCT244A is an advanced high speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with sub-micron silicon gate and
double-layermetal wiring C
2
MOS technology.
G output enable governsfour BUS BUFFERs.
M
(Micro Package)
(TSSOPPackage)
T
ORDERCODES :
74VHCT244AM 74VHCT244AT
This device is designed to be used with 3 state
memoryaddressdrivers, etc.
Power down protection is provided on all inputs
and outputs and 0 to 7V can be accepted on
inputs with no regard to the supply voltage. This
devicecan be usedto interface5Vto 3V.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
PIN CONNECTION AND IEC LOGIC SYMBOLS
August 1999
1/8
74VCHT244A
INPUT EQUIVALENTCIRCUIT
TRUTH TABLE
INPUT OUTPU T
GAnYn
LLL
LHH
HXZ
X:”H” or”L”
Z:Highimpedance
ABSOLUTE MAXIMUM RATINGS
PIN DESCRIPTION
PI N No SYM BO L NAM E AN D F UNCTIO N
1 1G Output Enable Input
2,4,6,8 1A1to1A4 Data Inputs
9,7,5,3 2Y1to2Y4 Data Outputs
11,13,15,17 2A1to2A4 Data Inputs
18,16,14,12 1Y1to1Y4 Data Outputs
19 2G Output Enable Input
10 GND Ground (0V)
20 V
Positive Supply Voltage
CC
Symb o l Para met er Value U n i t
V
V
V
V
I
I
OK
I
orI
I
CC
T
T
AbsoluteMaximum Ratingsarethosevaluesbeyond whichdamagetothedevice mayoccur.Functionaloperationunder these condition isnotimplied.
1)OutputinOFFState
2)HighorLow State
Supply Voltage -0.5to+7.0 V
CC
DC Input Voltage -0.5to+7.0 V
I
DC Output Voltage (see note 1) -0.5to+7.0 V
O
DC Output Voltage (see note 2) -0.5toVCC+0.5 V
O
DC Input Diode Current -20 mA
IK
DC Output Diode Current
DC Output Current ±25 mA
O
DC VCCor Ground Current ±50 mA
GND
Storage Temperature -65to+150
stg
Lead Temperature (10 sec) 300
L
20 mA
±
o
C
o
C
RECOMMENDED OPERATING CONDITIONS
Symb o l Para met er Value Unit
V
V
V
V
T
dt/dv
1)OutputinOFFState
2)HighorLow State
3)V
from0.8Vto 2 V
IN
2/8
Supply Voltage 4.5to5.5 V
CC
Input Voltage 0to5.5 V
I
Output Voltage (see note 1) 0to5.5 V
O
Output Voltage (see note 2) 0toV
O
Operating Temperature -40to+85
op
Input Rise and Fall Time (see note 3) (V
=5.0±0.5V)
CC
CC
0to20 ns/V
V
o
C
74VHCT244A
DC SPECIFICATIONS
Symb o l Para met er Test Con ditio ns Val u e Uni t
T
V
CC
High Level Input
V
IH
(V)
4.5to5.5 2 2 V
Min. Typ. Max. Min. Max.
Voltage
Low Level Input
V
IL
4.5to5.5 0.8 0.8 V
Voltage
High Level Output
V
OH
Voltage
Low Level Output
V
OL
Voltage
High Impedance
I
OZ
Output Leakage
4.5 IO=-50µA4.44.5 4.4
4.5 I
=-8mA 3.94 3.8
O
4.5 IO=50µA 0.0 0.1 0.1
4.5 I
4.5to5.5 VI=VIHorV
=8mA 0.36 0.44
O
IL
VO=0Vto5.5V
Current
Input Leakage Current 0to5.5 VI=5.5VorGND ±0.1 ±1.0 µA
I
I
Quiescent Supply
I
CC
5.5 VI=VCCorGND 2 20
Current
Additional Worst Case
∆I
CC
Supply Current
5.5 One Inputat3.4V,
other inputat V
CC
or
GND
I
Output Leakage
OPD
0V
=5.5V 0.5 5.0
OUT
Current
=25oC -40 t o 85oC
A
±0.25 ±2.5 µA
1.35 1.5 mA
µ
µ
V
V
A
A
AC ELECTRICAL CHARACTERISTICS (Inputtr=tf=3 ns)
Symbol Parameter Test Co ndition Value Unit
t
Propagation Delay
PLH
t
Time
PHL
Output Disable Time 5.0
t
PLZ
t
PHZ
t
Output Enable Time 5.0
PZL
t
PZH
(*) Voltagerangeis 5.0V±0.5V
V
(V)
5.0
5.0
5.0
CC
C
L
(pF)
(*)
(*)
(*)
(*)
(*)
15 5.4 7.4 1.0 8.5
50 5.9 8.4 1.0 9.5
15 RL=1K
50 8.2 11.4 1.0 13.0
50 RL=1K
Min. Typ. Max. Min. Max.
Ω
Ω
=25oC -40 t o 85oC
T
A
7.7 10.4 1.0 12.0
8.8 11.4 1.0 13.0
ns
ns
ns
3/8
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