SGS Thomson Microelectronics 74VHCT240A Datasheet
74VHCT240A
OCTAL BUS BUFFER
WITH 3 STATE OUTPUTS (INVERTED)
■ HIGHSPEED:t
■ LOW POWER DISSIPATION:
=4 µA (MAX.)at TA=25oC
I
CC
■ COMPATIBLEWITH TTLOUTPUTS:
=2V(MIN),VIL=0.8V(MAX)
V
IH
■ POWERDOWNPROTECTIONON INPUTS&
=5ns (TYP.)atVCC=5V
PD
OUTPUTS
■ SYMMETRICALOUTPUT IMPEDANCE:
|I
|=IOL=8 mA(MIN)
OH
■ BALANCEDPROPAGATIONDELAYS:
t
≅ t
PLH
PHL
■ OPERATINGVOLTAGERANGE:
(OPR)= 4.5Vto 5.5V
V
CC
■ PINANDFUNCTION COMPATIBLEWITH
74SERIES 240
■ IMPROVEDLATCH-UP IMMUNITY
■ LOWNOISE:V
= 0.9V(Max.)
OLP
DESCRIPTION
The 74VHCT240A is an advanced high-speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with sub-micron silicon gate and
double-layermetal wiringC
2
MOS technology.
M
(Micro Package)
(TSSOPPackage)
T
ORDERCODES :
74VHCT240AM 74VHCT240AT
G output enablegoverns four BUS BUFFERs.
This device is designed to be used with 3 state
memoryaddress drivers, 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 used to interface5V to 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
74VHCT240A
INPUT EQUIVALENTCIRCUIT
TRUTH TABLE
INPUT OUTPU T
GAnYn
LLH
LHL
HXZ
X:”H” or”L”
Z:Highimpedance
ABSOLUTE MAXIMUM RATINGS
PIN DESCRIPTION
PI N No SYM BO L NAM E AN D F UNCT I ON
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 whichdamagetothedevicemayoccur. Functional operationunderthese condition isnotimplied.
1)Outputin OFFState
2)HighorLowState
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
RECOMMENDEDOPERATINGCONDITIONS
Symb o l Para met er Value Unit
V
V
V
V
T
dt/dv
1)Outputin OFFState
2)HighorLowState
3)V
from0.8Vto 2V
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
74VHCT240A
DC SPECIFICATIONS
Symb o l Para met er Test Con dit io ns Val u e Un i 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=5.5Vor GND ±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 Inputat 3.4V,
other input at 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 (Input tr=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
(*) Voltagerangeis5.0V± 0.5V
V
(V)
5.0
5.0
5.0
CC
C
L
(pF)
(*)
(*)
(*)
(*)
(*)
15 5.6 7.8 1.0 9.0
50 6.1 8.8 1.0 10.0
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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