FAIRCHILD 74VHCT245AN

Revised April 2005
74VHCT245A
Octal Buffer/Line Driver with 3-STATE Outputs
General Description
Features
The VHCT245A is an advanced high speed CMOS octal
bus transceiver fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent
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 determined 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.
■ High Speed:
tPD
5.4 ns (typ) at VCC
5V
■ Power Down Protection on Inputs and Outputs
■ Low Power Dissipation: ICC
4 PA (Max) @ TA
25qC
■ Pin and Function Compatible with 74HCT245
Protection circuits ensure that 0V to 7V can be applied to
the input and output (Note 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 Code:
Order Number
Package Number
74VHCT245AM
74VHCT245ASJ
74VHCT245AMTC
74VHCT245AN
Package Description
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
M20D
Pb-Free 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
MTC20
N20A
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Pb-Free package per JEDED J-STD-020B.
Logic Symbol
Connection Diagram
IEEE/IEC
© 2005 Fairchild Semiconductor Corporation
DS500004
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74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
March 1997
74VHCT245A
Pin Descriptions
Pin Names
Description
OE
Output Enable Input
T/R
Transmit/Receive Input
A0–A7
Side A Inputs or 3-STATE Outputs
B0–B7
Side B Inputs or 3-STATE Outputs
Truth Table
Inputs
Outputs
OE
T/R
L
L
Bus B Data to Bus A
L
H
Bus A Data to Bus B
H
X
HIGH-Z State
H HIGH Voltage Level
L LOW Voltage Level
X Immaterial
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Recommended Operating
Conditions (Note 6)
0.5V to 7.0V
0.5V to 7.0V
Supply Voltage (VCC)
DC Input Voltage (VIN)
4.5V to 5.5V
Supply Voltage (VCC)
DC Output Voltage (VOUT )
0V to 5.5V
Input Voltage (VIN)
(Note 3)
(Note 4)
Input Diode Current (IIK)
Output Diode Current (IOK) (Note 5)
DC Output Current (IOUT )
DC VCC/GND Current (ICC)
Storage Temperature (TSTG)
0.5V to VCC 0.5V
0.5V to 7.0V
20 mA
r20 mA
r25 mA
r75 mA
65qC to 150qC
Output Voltage (VOUT)
0V to VCC
0V to 5.5V
40qC to 85qC
Operating Temperature (TOPR)
Input Rise and Fall Time (tr, tf)
VCC
5.0V r 0.5V
0 ns/V a 20 ns/V
Note 2: Absolute Maximum Ratings are values beyond which the device
may be damaged or have its useful life impaired. The databook specifications should be met, without exception, to ensure that the system design is
reliable over its power supply, temperature, and output/input loading variables. Fairchild does not recommend operation outside databook specifications.
Lead Temperature (TL)
260qC
(Soldering, 10 seconds)
(Note 3)
(Note 4)
Note 3: HIGH or LOW state. IOUT absolute maximum rating must be
observed.
OV.
Note 4: When outputs are in OFF-State or when VCC
Note 5: VOUT GND, V OUT ! VCC (Outputs Active).
Note 6: Unused inputs must be held HIGH or LOW. They may not float.
DC Electrical Characteristics
Symbol
VIH
VIL
VOH
Parameter
TA
Min
25qC
TA
Typ
Max
40qC to 85qC
Min
4.5
2.0
2.0
Input Voltage
5.5
2.0
2.0
Max
4.5
0.8
0.8
Input Voltage
5.5
0.8
0.8
HIGH Level
LOW Level
3-STATE Output
4.5
4.40
4.50
3.94
V
4.40
V
3.80
V
Input Leakage
ICC
Quiescent Supply
VIH IOH
50 PA
or VIL IOH
8 mA
VIN
VIH IOL
50 PA
or VIL IOL
8 mA
0.1
V
0.36
0.44
V
5.5
r0.25
r2.5
PA
0–5.5
r0.1
r1.0
PA
VIN
5.5V or GND
5.5
4.0
40.0
PA
VIN
VCC or GND
5.5
1.35
1.50
mA
VIN
3.4V
Off-State Current
IIN
Conditions
0.1
4.5
0.0
Units
V
LOW Level
Output Voltage
IOZ
(V)
HIGH Level
Output Voltage
VOL
V CC
VIN
VIN
VOUT
VIH or VIL
VCC or GND
Current
Current
ICCT
Maximum ICC/Input
Other Input
IOFF
Output Leakage Current
0.0
0.5
5.0
PA
VOUT
VCC or GND
5.5V
(Power Down State)
3
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74VHCT245A
Absolute Maximum Ratings(Note 2)
74VHCT245A
Noise Characteristics
Symbol
VCC
Parameter
TA
25qC
(V)
Typ
Limits
Units
Conditions
VOLP
(Note 7)
Quiet Output Maximum Dynamic VOL
5.0
1.2
1.6
V
CL
50 pF
VOLV
(Note 7)
Quiet Output Minimum Dynamic VOL
5.0
1.2
1.6
V
CL
50 pF
VIHD
(Note 7)
Minimum HIGH Level Dynamic Input Voltage
5.0
2.0
V
CL
50 pF
VILD
(Note 7)
Maximum LOW Level Dynamic Input Voltage
5.0
0.8
V
CL
50 pF
Note 7: Parameter guaranteed by design.
AC Electrical Characteristics
Symbol
Parameter
tPLH
Propagation Delay
tPHL
Time
tPZL
3-STATE Output
tPZH
Enable Time
tPLZ
3-STATE Output
tPHZ
Disable Time
tOSLH
Output to
tOSHL
Output Skew
CIN
V CC
TA
(V)
Min
5.0 r 0.5
5.0 r 0.5
5.0 r 0.5
25qC
Units
Conditions
Max
Min
Max
4.9
7.7
1.0
8.5
5.4
8.7
1.0
9.5
9.4
13.8
1.0
15.0
9.9
14.8
1.0
16.0
10.1
15.4
1.0
16.5
ns
RL
1.0
1.0
ns
(Note 8)
10
10
pF
VCC
Open
13
pF
VCC
5.0V
16
pF
(Note 9)
5.0 r 0.5
Input
40qC to 85qC
TA
Typ
4
ns
ns
RL
1 k:
1 k:
CL
15 pF
CL
50 pF
CL
15 pF
CL
50 pF
CL
50 pF
Capacitance
COUT
Output
Capacitance
CPD
Power Dissipation
Capacitance
Note 8: Parameter guaranteed by design. tOSLH
|tPLH max t PLH min|; tOSHL
|tPHL max tPHL min|
Note 9: 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.
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74VHCT245A
Physical Dimensions inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Number M20B
5
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74VHCT245A
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Pb-Free 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
Package Number M20D
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74VHCT245A
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
Package Number MTC20
7
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74VHCT245A Octal Buffer/Line Driver with 3-STATE Outputs
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Package Number N20A
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
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 THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
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.
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 to the
user.
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