tm
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
May 2007
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3
74VHCT245A
Octal Buffer/Line Driver with 3-STATE Outputs
Features
■
High Speed: t
PD
=
5.4ns (Typ.) at V
CC
=
5V
■
Power Down Protection on Inputs and Outputs
■
Low Power Dissipation: I
CC
=
4
µ
A (Max.) @ T
A
=
25°C
■
Pin and Function Compatible with 74HCT245
General Description
The VHCT245A is an advanced high speed CMOS octal
bus transceiver fabricated with silicon gate CMOS tech-
nology. It achieves high speed operation similar to equiv-
alent Bipolar Schottky TTL while maintaining the CMOS
low power dissipation. The VHCT245A is intended for
bidirectional asynchronous communication between
data busses. The direction of data transmission is deter-
mined by the level of the T/R input. The enable input can
be used to disable the device so that the busses are
effectively isolated.
Protection circuits ensure that 0V to 7V can be applied to
the input and output
(1)
pins without regard to the supply
voltage. These circuits prevent device destruction due to
mismatched supply and input/output voltages. This
device can be used to interface 5V to 3V systems and
two supply systems such as battery back up.
Note:
1. Outputs in OFF-State
Ordering Information
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the
ordering number. Pb-Free package per JEDED J-STD-020B.
Order Number
Package
Number Package Description
74VHCT245AM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
74VHCT245ASJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74VHCT245AMTC MTC20 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm
Wide
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 2
Connection Diagram
Pin Description
Logic Symbol
IEEE/IEC
Truth Table
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
Pin Names Description
OE Output Enable Input
T/R Transmit/Receive Input
A
0
–A
7
Side A Inputs or 3-STATE Outputs
B
0
–B
7
Side B Inputs or 3-STATE Outputs
Inputs
OutputsOE T/R
LLBus B Data to Bus A
LHBus A Data to Bus B
HXHIGH-Z State
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 3
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Recommended Operating Conditions
(5)
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to absolute maximum ratings.
Notes:
2. HIGH or LOW state. I
OUT
absolute maximum rating must be observed.
3. When outputs are in OFF-State or when V
CC
=
0V.
4. V
OUT
<
GND, V
OUT
>
V
CC
(Outputs Active).
5. Unused inputs must be held HIGH or LOW. They may not float.
Symbol Parameter Rating
V
CC
Supply Voltage –0.5V to +7.0V
V
IN
DC Input Voltage –0.5V to +7.0V
V
OUT
DC Output Voltage
Note 2
Note 3
–0.5V to V
CC
+ 0.5V
–0.5V to +7.0V
I
IK
Input Diode Current –20mA
I
OK
Output Diode Current
(4)
±20mA
I
OUT
DC Output Current ±25mA
I
CC
DC V
CC
/ GND Current ±75mA
T
STG
Storage Temperature –65°C to +150°C
T
L
Lead Temperature (Soldering, 10 seconds) 260°C
Symbol Parameter Rating
V
CC
Supply Voltage 4.5V to +5.5V
V
IN
Input Voltage 0V to +5.5V
V
OUT
Output Voltage
Note 2
Note 3
0V to V
CC
0V to +5.5V
T
OPR
Operating Temperature –40°C to +85°C
t
r
, t
f
Input Rise and Fall Time, V
CC
=
5.0V ± 0.5V 0ns/V ~ 20ns/V
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 4
DC Electrical Characteristics
Noise Characteristics
Note:
6. Parameter guaranteed by design.
Symbol Parameter V
CC
(V) Conditions
T
A
=
25°C
T
A
=
–40°C
to +85°C
UnitsMin. Typ. Max. Min. Max.
V
IH
HIGH Level Input
Voltage
4.5 2.0 2.0 V
5.5 2.0 2.0
V
IL
LOW Level Input
Voltage
4.5 0.8 0.8 V
5.5 0.8 0.8
V
OH
HIGH Level Output
Voltage
4.5 V
IN
=
V
IH
or V
IL
I
OH
=
–50µA 4.40 4.50 4.40 V
I
OH
=
–8mA 3.94 3.80
V
OL
LOW Level Output
Voltage
4.5 V
IN
=
V
IH
or V
IL
I
OL
=
50µA 0.0 0.1 0.1 V
I
OL
=
8mA 0.36 0.44
I
OZ
3-STATE Output
Off-State Current
5.5 V
IN
=
V
IH
or V
IL
,
V
OUT
=
V
CC
or GND
±0.25 ±2.5 µA
I
IN
Input Leakage
Current
0–5.5 V
IN
=
5.5V or GND ±0.1 ±1.0 µA
I
CC
Quiescent Supply
Current
5.5 V
IN
=
V
CC
or GND 4.0 40.0 µA
I
CCT
Maximum I
CC
/Input 5.5 V
IN
=
3.4V, Other
Input
=
V
CC
or GND
1.35 1.50 mA
I
OFF
Output Leakage
Current (Power
Down State)
0.0 V
OUT
=
5.5V 0.5 5.0 µA
Symbol Parameter V
CC
(V) Conditions
T
A
=
25°C
UnitsTyp. Limits
V
OLP(6)
Quiet Output Maximum
Dynamic V
OL
5.0 C
L
=
50pF 1.2 1.6 V
V
OLV(6)
Quiet Output Minimum
Dynamic VOL
5.0 CL = 50pF –1.2 –1.6 V
VIHD(6) Minimum HIGH Level
Dynamic Input Voltage
5.0 CL = 50pF 2.0 V
VILD(6) Maximum LOW Level
Dynamic Input Voltage
5.0 CL = 50pF 0.8 V
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 5
AC Electrical Characteristics
Notes:
7. Parameter guaranteed by design. tOSLH = |tPLH max – tPLH min|; tOSHL = |tPHL max – tPHL min|
8. CPD is defined as the value of the internal equivalent capacitance which is calculated from the operating
current consumption without load. Average operating current can be obtained by the equation:
ICC (Opr.) = CPD • VCC • fIN + ICC / 8 (per F/F). The total CPD when n pcs. of the Octal D Flip-Flop operates
can be calculated by the equation: CPD (total) = 20 + 12n.
Symbol Parameter VCC (V) Conditions
TA = 25°C
TA = –40°C
to +85°C
UnitsMin. Typ. Max. Min. Max.
tPLH, tPHL Propagation Delay
Time
5.0 ± 0.5 CL = 15pF 4.9 7.7 1.0 8.5 ns
CL = 50pF 5.4 8.7 1.0 9.5
tPZL, tPZH 3-STATE Output
Enable Time
5.0 ± 0.5 RL = 1kΩCL = 15pF 9.4 13.8 1.0 15.0 ns
CL = 50pF 9.9 14.8 1.0 16.0
tPLZ, tPHZ 3-STATE Output
Disable Time
5.0 ± 0.5 RL = 1kΩCL = 50pF 10.1 15.4 1.0 16.5 ns
tOSLH, tOSHL Output to Output
Skew
5.0 ± 0.5 (7) 1.0 1.0 ns
CIN Input Capacitance VCC = Open 4 10 10 pF
COUT Output Capacitance VCC = 5.0V 13 pF
CPD Power Dissipation
Capacitance
(8) 16 pF
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 6
Physical Dimensions
Dimensions are in millimeters unless otherwise noted.
Figure 1. 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Number M20B
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 7
Physical Dimensions (Continued)
Dimensions are in millimeters unless otherwise noted.
Figure 2. 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
Package Number M20D
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 8
Physical Dimensions (Continued)
Dimensions are in millimeters unless otherwise noted.
Figure 3. 20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Package Number MTC20
74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT245A Rev. 1.3 9
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FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS
HEREIN TO IMPROVE RELIABILITY, FUNCTION, OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE
APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS
PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S
WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body or
(b) support or sustain life, and (c) whose failure to perform
when properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to
result in a significant injury of the user.
2. A critical component in any component of a life support,
device, or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification Product Status Definition
Advance Information Formative or In Design This datasheet contains the design specifications for product
development. Specifications may change in any manner without notice.
Preliminary This datasheet contains preliminary data; supplementary data will be
published at a later date. Fairchild Semiconductor reserves the right to
make changes at any time without notice to improve design.
No Identification Needed
First Production
Full Production This datasheet contains final specifications. Fairchild Semiconductor
reserves the right to make changes at any time without notice to improve
design.
Obsolete Not In Production This datasheet contains specifications on a product that has been
discontinued by Fairchild Semiconductor. The datasheet is printed for
reference information only.
Rev. I27
