IDT54/74FCT245/A/C
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
FAST CMOS OCTAL
BIDIRECTIONAL
TRANSCEIVER
FEATURES:
DESCRIPTION:
IDT54/74FCT245/A/C
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IDT54FCT245 equivalent to FAST™ speed and drive
IDT54/74FCT245A 25% faster than FAST
IDT74FCT245C 40% faster than FAST
TTL input and output compatible
CMOS output level compatible
I
OL
= 64mA (commercial) and 48mA (military)
Current levels only 5µA max.
µ
CMOS power levels (2.5mW typ. static)
Direction control and overriding 3-state control
MIlitary product compliant to MIL-STD-883, Class B
Meets or exceeds JEDEC Standard 18 specifications
Available in the following packages:
– Commercial: SOIC
– Military: CERDIP, LCC
The IDT octal bidirectional transceivers are built using an advanced dual
metal CMOS technology. The FCT245 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 transceiver.
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.
The FCT245 transceivers have non-inverting outputs.
FUNCTIONAL BLOCK DIAGRAM
T/R
1
19
OE
A
0
2
18
3
B
0
A
1
17
B
1
A
2
4
16
B
2
A
3
5
15
B
3
6
A
4
14
B
4
A
5
7
13
8
12
B
5
A
6
B
6
A
7
9
11
B
7
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
MILITARY AND COMMERCIAL TEMPERATURE RANGES
1
JUNE 2002
DSC-5421/1
© 2002 Integrated Device Technology, Inc.
IDT54/74FCT245/A/C
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
PIN CONFIGURATION
T/R
A
1
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
19
18
17
16
15
14
13
12
11
OE
B
0
B
1
B
2
B
3
B
4
B
5
B
6
GND
A
7
B
7
B
6
3
2
1
20
19
18
17
16
15
14
9
10
11
12
13
A
2
A
3
A
4
A
5
A
6
A
0
INDEX
OE
T/R
1
20
V
CC
V
CC
4
5
6
7
8
B
0
B
1
B
2
B
3
B
4
B
7
CERDIP/ SOIC
TOP VIEW
LCC
TOP VIEW
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM
(2)
V
TERM
(3)
T
A
T
BIAS
T
STG
P
T
I
OUT
Rating
Terminal Voltage
with Respect to GND
Terminal Voltage
with Respect to GND
Operating Temperature
Temperature under BIAS
Storage Temperature
Power Dissipation
DC Output Current
0 to +70
–55 to +125
–55 to +125
0.5
120
–55 to +125
–65 to +135
–65 to +150
0.5
120
°C
°C
°C
W
mA
–0.5 to V
CC
–0.5 to V
CC
V
Commercial
–0.5 to +7
Military
–0.5 to +7
Unit
V
PIN DESCRIPTION
Pin Names
OE
T/R
A
0
- A
7
B
0
- B
7
Description
Output Enable Input (Active LOW)
Transmit/Recieve Input
Side A Inputs or 3-State Outputs
Side B Inputs or 3-State Outputs
FUNCTION TABLE
(1)
Inputs
OE
L
L
H
NOTE:
1. H = HIGH Voltage Level
X = Don’t Care
L = LOW Voltage Level
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. Input and Vcc terminals only.
3. Output and I/O terminals only.
T/R
L
H
X
B
5
Outputs
High Z State
Bus B Data to Bus A
Bus A Data to Bus B
CAPACITANCE
(T
A
= +25°C, F = 1.0MHz)
Symbol
C
IN
C
I/O
Parameter
(1)
Input Capacitance
I/O Capacitance
Conditions
V
IN
= 0V
V
OUT
= 0V
Typ.
6
8
Max.
10
12
Unit
pF
pF
NOTE:
1. This parameter is measured at characterization but not tested.
2
IDT54/74FCT245/A/C
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified: V
LC
= 0.2V; V
HC
= V
CC
- 0.2V
Commercial: T
A
= 0°C to +70°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
V
IK
I
OS
V
OH
Off State (High Impedance)
Output Current
Clamp Diode Voltage
Short Circuit Current
Output HIGH Voltage
V
CC
= Max.
Parameter
Input HIGH Level
Input LOW Level
Input HIGH Current
V
CC
= Max.
Input LOW Current
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
I
= V
CC
V
I
= 2.7V
V
I
= 0.5V
V
I
= GND
V
O
= V
CC
V
O
= 2.7V
V
O
= 0.5V
V
O
= GND
Min.
2
—
—
—
—
—
—
—
—
—
—
–60
V
HC
V
HC
2.4
2.4
—
—
—
—
Typ.
(2)
—
—
—
—
—
—
—
—
—
—
–0.7
–120
V
CC
V
CC
4.3
4.3
GND
GND
0.3
0.3
Max.
—
0.8
5
5
(4)
–5
(4)
–5
15
15
(4)
–15
(4)
–15
–1.2
—
—
—
—
—
V
LC
V
LC
(4)
0.55
0.55
µA
µA
Unit
V
V
V
CC
= Min., I
IN
= –18mA
V
CC
= Max., V
O
= GND
(3)
V
CC
= 3V, V
IN
= V
LC
or V
HC
, I
OH
= –32µA
V
CC
= Min
I
OH
= –300µA
V
IN
= V
IH
or V
IL
I
OH
= –12mA MIL
I
OH
= –15mA COM'L
V
CC
= 3V, V
IN
= V
LC
or V
HC
, I
OL
= 300µA
V
CC
= Min
I
OL
= 300µA
V
IN
= V
IH
or V
IL
I
OL
= 32mA MIL
I
OL
= 48mA COM'L
V
mA
V
V
OL
Output LOW Voltage
V
NOTES:
1. For conditions shown as Min. or Max., use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, +25°C ambient and maximum loading.
3. Not more than one output should be tested at one time. Duration of the test should not exceed one second.
4. This parameter is guaranteed but not ttested.
3
IDT54/74FCT245/A/C
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
V
LC
= 0.2V; V
HC
= V
CC
- 0.2V
Symbol
I
CC
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply
Current
(4)
Test Conditions
(1)
V
CC
= Max.
V
IN
≥
V
HC
; V
IN
≤
V
LC
V
CC
= Max.
V
IN
= 3.4V
(3)
V
CC
= Max.
Outputs Open
OE
= GND
T/R = GND or V
CC
One Input Toggling
50% Duty Cycle
V
CC
= Max.
Outputs Open
f
I
= 10MHz
50% Duty Cycle
T/R =
OE
= GND
One Bit Toggling
V
CC
= Max.
Outputs Open
f
I
= 2.5MHz
50% Duty Cycle
T/R =
OE
= GND
Eight Bits Toggling
NOTES:
1. For conditions shown as Min. or Max., 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
∆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 + fiNi)
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)
fi = Input Frequency
Ni = Number of Inputs at fi
All currents are in milliamps and all frequencies are in megahertz.
Min.
—
—
Typ.
(2)
0.2
0.5
0.15
Max.
1.5
2
0.25
Unit
mA
mA
mA/
MHz
V
IN
≥
V
HC
V
IN
≤
V
LC
—
I
C
Total Power Supply Current
(6)
V
IN
≥
V
HC
V
IN
≤
V
LC
(FCT)
V
IN
= 3.4V
V
IN
= GND
V
IN
≥
V
HC
V
IN
≤
V
LC
(FCT)
V
IN
= 3.4V
V
IN
= GND
—
2
4
mA
—
2.3
5
—
3.5
6.5
(5)
—
5.5
14.5
(5)
4
IDT54/74FCT245/A/C
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
MILITARY AND COMMERCIAL TEMPERATURE RANGES
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
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)
Condition
(1)
C
L
= 50pF
R
L
= 500Ω
54FCT245
Mil.
Min.
(2)
Max.
1.5
7.5
1.5
1.5
1.5
1.5
10
10
10
10
54/74FCT245A
Com'l.
Mil.
Min.
(2)
Max.
Min.
(2)
Max.
1.5
4.6
1.5
4.9
1.5
1.5
1.5
1.5
6.2
5
6.2
5
1.5
1.5
1.5
1.5
6.5
6
6.5
6
74FCT245C
Com'l.
Min.
(2)
Max.
1.5
4.1
1.5
1.5
1.5
1.5
5.8
4.8
5.8
4.8
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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