M54/74HCT245/640/643
M54/74HCT245/640/643
OCTAL BUS TRANSCEIVER (3-STATE): HCT245 NON INVERTING
HCT640 INVERTING, HCT643 INVERTING/NON INVERTING
.HIGH SPEED
tPD= 10 ns(TYP.) at VCC=5V
.LOWPOWERDISSIPATION
ICC=4µA (MAX.) at TA=25oC
.COMPATIBLE WITHTTL OUTPUTS
VIH= 2V (MIN.)VIL= 0.8V (MAX.)
.OUTPUT DRIVE CAPABILITY
15 LSTTL LOADS
B1R
(PlasticPackage)
F1R
(CeramicPackage)
.SYMMETRICALOUTPUT IMPEDANCE
|IOH|=IOL=6 mA(MIN)
.BALANCEDPROPAGATION DELAYS
t
PLH=tPHL
.PIN ANDFUNCTION COMPATIBLE
WITH 54/74LS245/640/643
DESCRIPTION
The M54/74HCT245, HCT640 and HCT643 utilise
silicongate C2MOS technology toachive operating
speedseqivalent to LSTTL devices.
Alongwith thelow power dissipationandhighnoise
immunity of standad CMOS integrated circuit, it
possesses the capability to drive 15 LSTTL loads.
TheseIC’s are intended fortwo-way asynchronous
communication between data buses, and the
direction of data trasmission is determined by DIR
input. The enable input (G) can be usedto disable
the device sothatthe busesare effectively isolated.
All input are equipped with protection circuits
against static discharge and transient discharge.
These integrated circuits have input and output
characteristics that are fully compatible with 54/74
LSTTL logic families. M54/74HCT devices are
designed to directly interface HSC2MOS systems
with TTL and NMOS components. They are also
plug in replacements for LSTTL devices giving a
reduction of powerconsumption.
IT IS PROHIBITED TO APPLY A SIGNAL TO A
BUS TERMINAL WHEN IT IS IN OUTPUT MODE
AND WHEN A BUS THERMINAL IS FLOATING
(HIGH IMPEDANCE STATE), IT IS REQUESTED
TO FIX THE INPUT LEVEL BY MEANS OF
EXTERNAL PULL DOWN OR PULL UP
RESISTOR.
M1R
(MicroPackage)
ORDER CODE S :
M54HC TXX X F1R M74HC TXX X M1R
M74HC TXXXB1 R M7 4HCT XXXC1 R
C1R
(Chip Carrier)
PIN CONNECTION (top view)
HCT245 HCT640 HCT643
October 1993
1/11
M54/M74HCT245/640/643
INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION
PIN No SYMBOL NAME AND FUNCTION
1 DIR Directional Control
2, 3, 4, 5,
6, 7, 8, 9
18, 17, 16,
15, 14, 13,
12, 11
19 G Output Enabel Input
10 GND Ground (0V)
20 V
IEC LOGIC SYMBOLS
HCT245 HCT640 HCT643
A1 to A8 Data Inputs/Outputs
B1 to B8 Data Inputs/Outputs
CC
(Active LOW)
Positive Supply Voltage
TRUTH TABLE
INPUT FUNCTION OUTPUT
G DIR A BUS B BUS HCT245 HCT640 HCT643
L L OUTPUT INPUT A = B A = B A = B
L H INPUT OUTPUT B = A B = A B = A
HXZZZZZ
X: ”H” or”L”
Z: High impedance
2/11
LOGIC DIAGRAM (HCT640)
M54/M74HCT245/640/643
NOTE:IN CASE OF HCT245OR HCT643,INPUTINVERTERSMARKED* AT A BUSAND B BUS AREELIMINATEDRESPECTIVELY
ABSOLU TE M AXIMU M R AT ING S
Symbol Parameter Value Unit
V
CC
V
V
O
I
IK
I
OK
I
O
I
or I
CC
P
D
T
stg
T
AbsoluteMaximumRatingsarethose values beyondwhichdamage tothedevicemayoccur. Functional operationunder these conditionisnotimplied.
(*)500 mW: ≅ 65oC derateto300 mWby 10mW/oC: 65oCto85oC
Supply Voltage -0.5 to +7 V
DC Input Voltage -0.5 to VCC+ 0.5 V
I
DC Output Voltage -0.5 to VCC+ 0.5 V
DC Input Diode Current ± 20 mA
DC Output Diode Current ± 20 mA
DC Output Source Sink Current Per Output Pin ± 35 mA
DC VCCor Ground Current ± 70 mA
GND
Power Dissipation 500 (*) mW
Storage Temperature -65 to +150
Lead Temperature (10sec) 300
L
o
C
o
C
3/11
M54/M74HCT245/640/643
RECO MM ENDED OPERAT IN G CO NDITI ONS
Symbol Parameter Value Unit
V
V
V
T
t
r,tf
DC SPECIFICATIONS
Symbol Parameter
V
V
V
OH
V
OL
I
I
OZ
I
CC
∆I
Supply Voltage 4.5 to 5.5 V
CC
Input Voltage 0 to V
I
Output Voltage 0 to V
O
Operating Temperature: M54HC Series
op
M74HC Series
CC
CC
-55 to +125
-40 to +85
Input Rise and Fall Time (VCC= 4.5 to 5.5V) 0 to 500 ns
Test Conditions Value
T
High Level Input
IH
Voltage
V
(V)
4.5
=25oC
CC
A
54HC and 74HC
Min. Typ. Max. Min. Max. Min. Max.
2.0 2.0 2.0 V
to
-40 to 85oC
74HC
-55 to 125oC
5.5
Low Level Input
IL
Voltage
4.5
to
0.8 0.8 0.8 V
5.5
High Level
Output Voltage
Low Level Output
Voltage
Input Leakage
I
Current
3 State Output
VI=
IO=-20 µA 4.4 4.5 4.4 4.4
V
IH
4.5
or
I
=-6.0 mA 4.18 4.31 4.13 4.10
O
V
IL
VI=
IO=20µA 0.0 0.1 0.1 0.1
V
IH
4.5
or
I
= 6.0 mA 0.17 0.26 0.33 0.4
O
V
IL
VI=VCCor GND ±0.1 ±1 ±1 µA
5.5
5.5 VI=VCCor GND ±0.5 ±5.0 ±10 µA
Off State Current
Quiescent Supply
5.5 VI=VCCor GND 4 40 80 µA
Current
Additional worst
CC
case supply
current
5.5 Per Input pin
VI= 0.5V or
V
= 2.4V
I
2.0 2.9 3.0 mA
Other Inputs at
VCCor GND
IO=0
54HC
V
V
o
C
o
C
Unit
V
V
4/11