IDT54/74FCT245T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
FAST CMOS OCTAL
BIDIRECTIONAL
TRANSCEIVER
FEATURES:
−
−
−
−
−
−
−
−
−
−
Low input and output leakage
≤1µ
A (max.)
Extended commercial range of –40°C to +85°C
CMOS power levels
True TTL input and output compatibility
•
V
OH
= 3.3V (typ.)
•
V
OL
= 0.3V (typ.)
Meets or exceeds JEDEC standard 18 specifications
Product available in Radiation Tolerant and Radiation Enhanced
versions
Military product compliant to MIL-STD-883, Class B and DESC
listed (dual marked)
Available in DIP, SOIC, SSOP, QSOP, TSSOP, CERPACK, and
LCC packages
Std., A, C and D speed grades
High drive outputs (-15mA I
OH
, 64mA I
OL
)
IDT54/74FCT245T/AT/CT/DT
DESCRIPTION:
The IDT octal bidirectional transceivers are built using an advanced dual
metal CMOS technology. The FCT245T is designed for asynchronous
two-way communication between data buses. 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, and
receive (active low) from B ports to A ports. The output enable (OE) input,
when high, disables both A and B ports by placing them in high Z condition.
FUNCTIONAL BLOCK DIAGRAM
T/
R
OE
A
0
B
0
A
1
B
1
A
2
B
2
A
3
B
3
A
4
B
4
A
5
B
5
A
6
B
6
A
7
B
7
MILITARY AND COMMERCIAL TEMPERATURE RANGES
1
c
1999 Integrated Device Technology, Inc.
JANUARY 2000
DSC-5510/-
IDT54/74FCT245T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN CONFIGURATION
T/R
A
1
OE
19
18
17
L20-2
16
15
14
9
10
11
12
13
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
GND
2
3
4
5
6
7
8
9
10
P20-1
D20-1
SO20-2
SO20-7
SO20-8
SO20-9
E20-1
19
18
17
16
15
14
13
12
11
OE
B
0
A
2
B
1
A
3
B
2
A
4
B
3
B
4
B
5
B
6
B
7
A
5
A
6
6
7
8
5
4
3
2
1
20
A
0
T/R
1
20
V
CC
INDEX
V
CC
B
0
B
1
B
2
B
3
B
4
A
7
B
7
B
6
DIP/ SOIC/ SSOP/ QSOP/ TSSOP/ CERPACK
TOP VIEW
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM(2)
V
TERM(3)
T
STG
I
OUT
Rating
Terminal Voltage with Respect to GND
Terminal Voltage with Respect to GND
Storage Temperature
DC Output Current
Max.
–0.5 to +7
–0.5 to V
CC
+0.5
–65 to +150
–60 to +120
Unit
V
V
°C
mA
8T-link
PIN DESCRIPTION
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
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM
RATINGS may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at these or
any other conditions above those indicated in the operational sections
of this specification is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect reliability.
No
terminal voltage may exceed Vcc by +0.5V unless otherwise noted.
2. Inputs and Vcc terminals only.
3. Outputs and I/O terminals only.
FUNCTION TABLE
Inputs
OE
L
L
H
T/R
L
H
X
GND
LCC
TOP VIEW
(1)
Outputs
Bus B Data to Bus A
Bus A Data to Bus B
High Z State
CAPACITANCE
(T
A
= +25
O
C, f = 1.0MHz)
Symbol
C
IN
C
OUT
Parameter
(1)
Input Capacitance
Output Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
Typ.
6
8
Max.
10
12
Unit
pF
pF
8T-link
NOTE:
1. H = HIGH Voltage Level
L = LOW Voltage Level
X = Don't Care
NOTE:
1. This parameter is measured at characterization but not tested.
2
B
5
IDT54/74FCT245T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Commercial: T
A
= -40°C to +85°C, V
CC
= 5.0V ± 5%; Military: T
A
= -55°C to +125°C, V
CC
= 5.0V ± 10%
Symbol
V
IH
V
IL
I
IH
I
IL
I
OZH
I
OZL
I
I
V
IK
V
H
I
CC
Parameter
Input HIGH Level
Input LOW Level
Input HIGH Current
(4)
Input LOW Current
(4)
High Impedance Output Current
(3-State output pins)
(4)
Input HIGH Current
Clamp Diode Voltage
Input Hysteresis
Quiescent Power Supply Current
V
CC
= Max., V
I
= V
CC
(Max.)
V
CC
= Min., I
IN
= –18mA
—
V
CC
= Max., V
IN
=
GND or
V
CC
V
CC
= Max.
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
CC
= Max.
V
I
= 2.7V
V
I
= 0.5V
V
O
= 2.7V
V
O
= 0.5V
Min.
2
—
—
—
—
—
—
—
—
—
Typ.
(2)
—
—
—
—
—
—
—
–0.7
200
0.01
Max.
—
0.8
±1
±1
±1
±1
±1
–1.2
—
1
µA
V
mV
mA
µA
Unit
V
V
µA
OUTPUT DRIVE CHARACTERISTICS
Symbol
V
OH
Parameter
Output HIGH Voltage
Test Conditions
(1)
V
CC
= Min.
I
OH
= –6mA MIL.
V
IN
=
V
IH
or V
IL
I
OH
= –8mA COM’L
I
OH
= –12mA MIL.
I
OH
= –15mA COM’L.
V
CC
= Min.
I
OL
= 48mA MIL.
V
IN
=
V
IH
or V
IL
I
OL
= 64mA COM’L.
(3)
V
CC
= Max, V
O
= GND
Min.
2.4
2
—
–60
Typ.
(2)
3.3
3
0.3
–120
Max.
—
—
0.55
–225
Unit
V
V
V
mA
V
OL
I
OS
Output LOW Voltage
Short Circuit Current
NOTES:
1. For conditions shown as max. or min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient.
3. Not more than one output should be shorted at one time. Duration of the short circuit test should not exceed one second.
4. The test limit for this parameter is ±5µA at T
A
= -55°C.
3
IDT54/74FCT245T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
Symbol
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply Current
(4)
Test Conditions
(1)
V
CC
= Max.
V
IN
= 3.4V
(3)
V
CC
= Max.
Outputs Open
OE
= T/R = GND
One Input Toggling
50% Duty Cycle
V
CC
= Max.
Outputs Open
fi = 10MHz
50% Duty Cycle
OE
= T/R = GND
One Bit Toggling
V
CC
= Max.
Outputs Open
fi = 2.5MHz
50% Duty Cycle
OE
= T/R = GND
Eight Bits Toggling
Min.
—
—
Typ.
(2)
0.5
0.15
Max.
2
0.25
Unit
mA
mA/
MHz
V
IN
= V
CC
V
IN
= GND
I
C
Total Power Supply Current
(6)
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4
V
IN
= GND
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4
V
IN
= GND
—
1.5
3.5
mA
—
1.8
4.5
—
3
6
(5)
—
5
14
(5)
NOTES:
1. For conditions shown as Max. or Min., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient.
3. Per TTL driven input (V
IN
= 3.4V). All other inputs at V
CC
or GND.
4. This parameter is not directly testable, but is derived for use in Total Power Supply Calculations.
5. Values for these conditions are examples of the I
CC
formula. These limits are guaranteed but not tested.
6. I
C
= I
QUIESCENT
+ I
INPUTS
+ I
DYNAMIC
I
C
= I
CC
+
∆I
CC
D
H
N
T
+ I
CCD
(f
CP/
2 + f
i
N
i
)
I
CC
= Quiescent Current
∆I
CC
= Power Supply Current for a TTL High Input (V
IN
= 3.4V)
D
H
= Duty Cycle for TTL Inputs High
N
T
= Number of TTL Inputs at D
H
I
CCD
= Dynamic Current Caused by an Input Transition Pair (HLH or LHL)
f
CP
= Clock Frequency for Register Devices (Zero for Non-Register Devices)
f
i
= Input Frequency
N
i
= Number of Inputs at f
i
All currents are in milliamps and all frequencies are in megahertz.
4
IDT54/74FCT245T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
SWITCHING CHARACTRISTICS OVER OPERATING RANGE - COMMERCIAL
FCT245T
Symbol
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
PZH
t
PZL
t
PHZ
t
PLZ
Parameter
Propagation Delay
A to B, B to A
Output Enable Time
OE
to A or B
Output Disable Time
OE
to A or B
Output Enable Time
T/R to A or B
(3)
Output Disable Time
T/R to A or B
(3)
Conditions
(1)
C
L
= 50 pF
R
L
= 500Ω
Min.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
7
9.5
7.5
9.5
7.5
FCT245AT
Min
.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
4.6
6.2
5
6.2
5
FCT245CT
Min
.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
4.1
5.8
4.8
5.8
4.8
FCT245DT
Min.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
3.8
5
4.3
5
4.3
Unit
ns
ns
ns
ns
ns
SWITCHING CHARACTRISTICS OVER OPERATING RANGE - MILITARY
FCT245T
Symbol
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
t
PZH
t
PZL
t
PHZ
t
PLZ
Parameter
Propagation Delay
A to B, B to A
Output Enable Time
OE
to A or B
Output Disable Time
OE
to A or B
Output Enable Time
T/R to A or B
(3)
Output Disable Time
T/R to A or B
(3)
Conditions
(1)
C
L
= 50 pF
R
L
= 500Ω
Min.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
7.5
10
10
10
10
FCT245AT
Min
.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
4.9
6.5
6
6.5
6
FCT245CT
Min
.
(2)
1.5
1.5
1.5
1.5
1.5
Max.
4.5
6.2
5.2
6.2
5.2
Unit
ns
ns
ns
ns
ns
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
3. This parameter is guaranteed but not tested.
5
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