74VHCT245A
OCTAL BUS
TRANSCEIVER (3-STATE)
■ HIGH SPEED: t
■ LOW POWER DISSIPATION:
I
= 4 µA (MAX.) at TA=25°C
CC
■ COMPATIBLE WITH TTL OUTP U TS:
V
= 2V (M IN.), V
IH
■ POWER DOWN PROTECTION ON INPUTS
= 4.5 ns (TYP.) at VCC = 5V
PD
= 0.8V (MAX)
IL
& OUTPUTS
■ SYMMETRICAL OUTPUT IMPEDANCE:
|I
| = IOL = 8 mA (MIN)
OH
■ BALANCED PROPAGATION DELAYS:
t
≅ t
PLH
PHL
■ OPERATING VOLTAGE RANGE:
V
(OPR) = 4.5V to 5.5V
CC
■ PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 245
■ IMPROVED LATCH-UP IMMUNITY
■ LOW NOISE: V
= 0.9V (MAX.)
OLP
DESCRIPTION
The 74VHCT245A is an advanced high-speed
CMOS OCTAL BUS TRANSCEIVER (3-STATE)
fabricated with sub-micron silicon gate and
double-layer metal wiring C
2
MOS technology.
This IC is intended for two-way asynchronous
communication between data busses; the
TSSOPSOP
Table 1: Order Codes
PACKAGE T & R
SOP 74VHCT245AMTR
TSSOP 74VHCT245ATTR
direction of data transmission is determined by
DIR input. The enable input G
can be used to
disable the device so that the busses are
effectivel y isolated.
All inputs and outputs are equipped with
protection circuits against static disc harge, giving
them 2KV ESD immunity and transient excess
voltage.
All floating bus terminals during High Z State must
be held HIGH or LOW.
Figure 1: Pin Connection And IEC Logic Symbols
Rev. 4
1/13December 2004
74VHCT245A
Figure 2: Input/ Output Equivalent Circuit
Figure 3: Input Equivalent Circuit Table 2: Pin Description
PIN N° 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
10 GND Ground (0V)
20 V
A1 to A8 Data Inputs/Outputs
B1 to B8 Data Inputs/Outputs
Enable Input
CC
Positive Supply Voltage
Table 3: Truth Table
INPUTS FUNCTION
G
L L OUTPUT INPUT A = B
L H INPUT OUTPUT B = A
HXZZZ
X : Don‘t Ca re
Z : High Impedance
2/13
DIR A BUS B BUS
OUTPUT
74VHCT245A
Table 4: Absolute Maximum Ratings
Symbol Parameter Value Unit
V
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
1) Output in OFF State
2) High or Low State. I
Table 5: Recommended Operating Conditions
Symbol Parameter Value Unit
V
V
V
V
T
dt/dv
Supply Voltage
CC
DC Input Voltage (DIR, G)
I
DC BUS I/O Voltage (see note 1)
I/O
DC BUS I/O Voltage (see note 2) -0.5 to VCC + 0.5
I/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
absolute maximum rating must be observed
O
Supply Voltage
CC
Input Voltage
I
BUS I/O Voltage (see note 1)
I/O
BUS I/O Voltage (see note 2) 0 to V
I/O
Operating Temperature
op
Input Rise and Fall Time (see note 3) (V
= 5.0 ± 0.5V)
CC
-0.5 to +7.0 V
-0.5 to +7.0 V
-0.5 to +7.0 V
- 20 mA
± 20 mA
± 25 mA
± 75 mA
-65 to +150 °C
300 °C
4.5 to 5.5 V
0 to 5.5 V
0 to 5.5 V
CC
-55 to 125 °C
0 to 20 ns/V
V
V
1) Output in OFF State
2) High or Low State. I
3) V
from 0.8V to 2V
IN
absolute maximum rating must be observed
O
3/13
74VHCT245A
Table 6: DC Specifications
Symbol Parameter
V
V
V
+I
I
High Level Input
IH
Voltage
Low Level Input
V
IL
Voltage
High Level Output
OH
Voltage
Low Level Output
OL
Voltage
I
High Impedance
OZ
Output Leakage
Current
Input Leakage
I
I
Current
Quiescent Supply
I
CC
Current
Additional Worst
CC
Case Supply
Current
Output Leakage
OPD
Current
4.5 to
4.5 to
Test Condition Value
= 25°C
T
V
CC
(V)
5.5
5.5
4.5
4.5
4.5
4.5
5.5
0 to
5.5
5.5
=-50 µA
I
O
=-8 mA
I
O
=50 µA
I
O
=8 mA
I
O
= VIH or V
V
I
VO = 0V to 5.5V
= 5.5V or GND
V
I
= VCC or GND
V
I
IL
A
Min. Typ. Max. Min. Max. Min. Max.
222V
0.8 0.8 0.8 V
4.4 4.5 4.4 4.4
3.94 3.8 3.7
0.0 0.1 0.1 0.1
0.36 0.44 0.55
±0.25 ± 2.5 ± 2.5 µA
± 0.1 ± 1.0 ± 1.0 µA
One Input at 3.4V,
5.5
other input at V
CC
1.35 1.5 1.5 mA
or GND
= 5.5V
0
V
OUT
0.5 5.0 5.0 µA
-40 to 85°C -55 to 125°C
Unit
V
V
44040µA
Table 7: AC Electrical Characteristics (Input t
Test Condition Value
Symbol Parameter
t
Propagation Delay
PLH
t
t
t
t
t
t
OSLH
t
OSHL
(*) Voltage range is 5.0V ± 0.5V
Note 1: Parameter guaranteed by design. t
Time
PHL
Output Enable
PZL
Time
PZH
Output Disable
PLZ
Time
PHZ
Output to Output
Skew Time (note 1)
(*)
(V)
C
(pF)
L
V
CC
5.0 15 4.5 7.5 1.0 8.5 1.0 10.0
5.0 50 5.3 8.7 1.0 9.5 1.0 11.0
5.0 15
5.0 50 9.7 14.8 1.0 16.0 1.0 17.0
RL = 1KΩ
5.0 50 RL = 1K
5.0 50 1.0 1.0 1.0 ns
= |t
pLHm
- t
pLHn
soLH
= tf = 3ns)
r
= 25°C
T
A
-40 to 85°C -55 to 125°C
Min. Typ. Max. Min. Max. Min. Max.
9.0 13.8 1.0 15.0 1.0 16.0
Ω 10.0 15.4 1.0 16.5 1.0 17.5 ns
|, t
= |t
- t
soHL
pHLm
pHLn
|
Unit
ns
ns
4/13
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