74FR2245 Octal Bidirectional Transceiver with 3-STATE Outputs
April 1995
Revised August 1999
74FR2245
Octal Bidirectional Transceiver with 3-STATE Outputs
General Description
The 74FR2245 contains eight non-inverting bidirectional
buffers with 3-STATE outputs and is intended for bus-ori-
ented applications. Current sinking capability is 64 mA on
the A Port. The Transmit/Receive (T/R) input determines
the direction of data flow through the bidirectional trans-
ceiver. Transmit (active-HIGH) enables data from A Ports
to B Ports; Receive (active-LOW) enables data from B
Ports to A Ports. The Output Enable input, when HIGH, dis-
ables both A and B Ports by placing them in a High Z con-
dition.
Features
s
Non-inverting buffers
s
Bidirectional data path
s
Guaranteed pin-to-pin skew
s
25Ω series resistors in B outputs eliminate the need for
external resistors
s
3-STATE outputs drive bus lines or buffer memory
address resistors
Ordering Code:
Order Number
74FR2245SC
Package Number
M20B
Package Description
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” letter to the ordering code.
Logic Symbol
Connection Diagram
Pin Descriptions
Pin Names
OE
T/R
A
0
–A
7
B
0
–B
7
Description
Output Enable Input (Active-LOW)
Transmit/Receive Input
Side A Inputs or 3-STATE Outputs
Side B Inputs or 3-STATE Outputs
Truth Table
Inputs
OE
L
L
H
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial
Output
T/R
L
H
X
Bus B Data to Bus A
Bus A Data to Bus B
High Z State
© 1999 Fairchild Semiconductor Corporation
DS012114
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74FR2245
Logic Diagram
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2
74FR2245
Absolute Maximum Ratings
(Note 1)
Storage Temperature
Ambient Temperature under Bias
Junction Temperature under Bias
V
CC
Pin Potential to Ground Pin
Input Voltage (Note 2)
Input Current (Note 2)
Voltage Applied to Output
in HIGH State (with V
CC
=
0V)
Standard Output
3-STATE Output
Current Applied to Output
in LOW State (Max)
ESD Last Passing Voltage (Min)
twice the rated I
OL
(mA)
4000V
−0.5V
to V
CC
−0.5V
to
+5.5V
−65°C
to
+150°C
−55°C
to
+125°C
−55°C
to
+150°C
−0.5V
to
+7.0V
−0.5V
to
+7.0V
−30
mA to
+5.0
mA
Recommended Operating
Conditions
Free Air Ambient Temperature
Supply Voltage
0°C to
+70°C
+4.5V
to
+5.5V
Note 1:
Absolute maximum ratings are values beyond which the device
may be damaged or have its useful life impaired. Functional operation
under these conditions is not implied.
Note 2:
Either voltage limit or current limit is sufficient to protect inputs.
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
CD
V
OH
V
OL
Parameter
Input HIGH Voltage
Input LOW Voltage
Input Clamp Diode Voltage
Output HIGH Voltage
Output LOW Voltage
2.4
2.0
0.5
0.75
0.55
I
IH
I
BVI
I
BVIT
I
IL
V
ID
I
OD
I
IH
+
I
OZH
I
IL
+
I
OZL
I
OS
I
CEX
I
ZZ
I
CCH
I
CCL
I
CCZ
C
IN
Input HIGH Current
Input HIGH Current
Breakdown Test
Input HIGH Current
Breakdown Test (I/O)
Input LOW Current
Input Leakage Test
Output Circuit Leakage Current
Output Leakage Current
Output Leakage Current
Output Short-Circuit Current
Output HIGH Leakage Current
Bus Drainage Test
Power Supply Current
Power Supply Current
Power Supply Current
Input Capacitance
55
75
55
8.0
17.0
−100
4.75
3.75
25
−150
−225
50
100
75
110
75
5
7
100
−250
Min
2.0
0.8
−1.2
Typ
Max
Units
V
V
V
V
V
V
V
V
µA
µA
µA
µA
V
µA
µA
µA
mA
µA
µA
mA
mA
mA
pF
pF
Min
Min
Min
Max
Max
Max
Max
Max
Max
Max
0.0
0.0
Max
Max
Max
Max
0.0
Max
Max
Max
5.0
5.0
V
CC
Conditions
Recognized HIGH Signal
Recognized LOW Signal
I
IN
= −18
mA
I
OH
= −3
mA (A
n
, B
n
)
I
OH
= −15
mA (A
n
, B
n
)
I
OL
=
1 mA (B
n
)
I
OL
=
12 mA (B
n
)
I
OL
=
64 mA (A
n
)
V
IN
=
2.7V (OE, T/R)
V
IN
=
7.0V (OE, T/R)
V
IN
=
5.5V (A
n
, B
n
)
V
IN
=
0.5V (OE, T/R)
I
ID
=
1.9
µA
All Other Pins Grounded
V
IOD
=
150 mV
All Other Pins Grounded
V
OUT
=
2.7V (A
n
, B
n
)
V
OUT
=
0.5V (A
n
, B
n
)
V
OUT
=
0.0V (A
n
, B
n
)
V
OUT
=
V
CC
(A
n
, B
n
)
V
OUT
=
5.25V (A
n
, B
n
)
All Outputs HIGH
All Outputs LOW
Outputs 3-STATE
OE, T/R
A
n
, B
n
3
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74FR2245
AC Electrical Characteristics
T
A
= +25°C
Symbol
Parameter
Min
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
Output Disable Time
Propagation Delay
A
n
to B
n
or B
n
to A
n
Output Enable Time
1.0
1.0
2.5
2.5
1.7
1.7
V
CC
= +5.0V
C
L
=
50 pF
Typ
Max
4.4
4.4
7.5
7.5
6.5
6.5
T
A
=
0°C to
+70°C
V
CC
= +5.0V
C
L
=
50 pF
Min
1.0
1.0
2.5
2.5
1.7
1.7
Max
4.4
4.4
7.5
7.5
6.5
6.5
ns
ns
ns
Units
Extended AC Electrical Characteristics
Symbol
Parameter
T
A
=
0°C to
+70°C
V
CC
= +5.0V
C
L
=
50 pF
Eight Outputs Switching
(Note 3)
Min
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
OSHL
(Note 5)
t
OSLH
(Note 5)
t
OST
(Note 5)
Pin-to-Pin Skew
for HL Transitions
Pin-to-Pin Skew
for LH Transitions
Pin-to-Pin Skew
for HL/LH Transitions
Output Disable Time
Propagation Delay
A
n
to B
n
or B
n
to A
n
Output Enable Time
1.0
1.0
2.5
2.5
1.3
1.3
Max
7.0
7.0
10.0
10.0
6.5
6.5
1.7
1.0
3.3
Min
2.5
2.5
Max
10.0
10.0
ns
ns
ns
ns
ns
ns
T
A
=
0°C to
+70°C
V
CC
= +5.0V
C
L
=
250 pF
(Note 4)
Units
Note 3:
This specification is guaranteed but not tested. The limits apply to propagation delays for all paths described switching in phase,
i.e., all LOW-to-HIGH, HIGH-to-LOW, 3-STATE-to-HIGH, etc.
Note 4:
These specifications guaranteed but not tested. The limits represent propagation delays with 250 pF load capacitors in place of the 50 pF load
capacitors in the standard AC load. This specification pertains to single output switching only.
Note 5:
Skew is defined as the absolute value of the difference between the actual propagation delays for any two outputs of the same device. The specifi-
cation applies to any outputs switching HIGH-to-LOW (t
OSHL
), LOW-to-HIGH (t
OSLH
), or HIGH-to-LOW and/or LOW-to-HIGH (t
OST
). Specifications guaran-
teed with all outputs switching in phase.
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4
74FR2245 Octal Bidirectional Transceiver with 3-STATE Outputs
Physical Dimensions
inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
Package Number M20B
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:
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 rea-
sonably expected to result in a significant injury to the
user.
5
2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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