IDT74FCT2245AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
INDUSTRIAL TEMPERATURE RANGE
FAST CMOS OCTAL
BIDIRECTIONAL
TRANSCEIVER
FEATURES:
•
•
•
•
•
•
•
•
IDT74FCT2245AT/CT
A and C grades
Low input and output leakage
≤
1µA (max.)
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
Resistor outputs -15mA I
OH
, 12mA I
OL
Reduced system switching noise
Available in SOIC, QSOP, and TSSOP packages
DESCRIPTION:
The IDT octal bidirectional transceivers are built using an advanced dual
metal CMOS technology. The FCT2245T 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.
The FCT2245T has balanced drive outputs with current limiting resistors.
This offers low ground bounce, minimal undershoot and controlled output
fall times- reducing the need for external series terminating resistors. The
FCT2245T parts are plug-in replacements for FCT245T parts.
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
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
INDUSTRIAL TEMPERATURE RANGE
1
JUNE 2002
DSC-5511/2
© 2002 Integrated Device Technology, Inc.
IDT74FCT2245AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
INDUSTRIAL TEMPERATURE RANGE
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol
V
TERM
(2)
Description
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
T/R
A
0
A
1
A
2
A
3
A
4
A
5
A
6
A
7
GND
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
V
CC
OE
B
0
B
1
B
2
B
3
B
4
B
5
B
6
B
7
V
TERM
(3)
T
STG
I
OUT
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. Output and I/O terminals only.
CAPACITANCE
(T
A
= +25°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
NOTE:
1. This parameter is measured at characterization but not tested.
SOIC/ QSOP/ TSSOP
TOP VIEW
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 BInputs 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
T/R
L
H
X
Outputs
Bus B Data to Bus A
Bus A Data to Bus B
High Z State
2
IDT74FCT2245AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
INDUSTRIAL TEMPERATURE RANGE
DC ELECTRICAL CHARACTERISTICS OVER OPERATING RANGE
Following Conditions Apply Unless Otherwise Specified:
Industrial: T
A
= –40°C to +85°C, V
CC
= 5.0V ±5%
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
(4)
Clamp Diode Voltage
Input Hysteresis
Quiescent Power Supply Current
V
CC
= Max.
V
IN
= GND or V
CC
V
CC
= Max., V
I
= V
CC
(Max.)
V
CC
= Min., I
IN
= –18mA
—
Test Conditions
(1)
Guaranteed Logic HIGH Level
Guaranteed Logic LOW Level
V
CC
= Max.
V
CC
= Max.
V
CC
= Max.
V
I
= 2.7V
V
I
= 0.5V
V
I
= 2.7V
V
I
= 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
Unit
V
V
µA
µA
µA
OUTPUT DRIVE CHARACTERISTICS
Symbol
I
ODL
I
ODH
V
OH
V
OL
Parameter
Output LOW Current
Output HIGH Current
Output HIGH Voltage
Output LOW Voltage
Test Conditions
(1)
V
CC
= 5V, V
IN
= V
IH
or V
IL
, V
OUT
= 1.5V
(3)
V
CC
= 5V, V
IN
= V
IH
or V
IL
, V
OUT
= 1.5V
(3)
V
CC
= Min
I
OH
= –15mA
V
IN
= V
IH
or V
IL
V
CC
= Min
I
OL
= 12mA
V
IN
= V
IH
or V
IL
Min.
16
-16
2.4
—
Typ.
(2)
48
-48
3.3
0.3
Max.
—
—
—
0.5
Unit
mA
mA
V
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.
3. Not more than one output should be tested at one time. Duration of the test should not exceed one second.
4. The test limit for this parameter is ±5µA at TA = -55°C.
3
IDT74FCT2245AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
INDUSTRIAL TEMPERATURE RANGE
POWER SUPPLY CHARACTERISTICS
Symbol
∆I
CC
I
CCD
Parameter
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply
Current
(4)
V
CC
= Max.
V
IN
= 3.4V
(3)
V
CC
= Max.
Outputs Open
OE
= T/R = GND
One Input Toggling
50% Duty Cycle
I
C
Total Power Supply Current
(6)
V
CC
= Max.
Outputs Open
fi = 10MHz
50% Duty Cycle
OE
= T/R = GND
One BitToggling
V
CC
= Max.
Outputs Open
fi = 2.5MHz
50% Duty Cycle
OE
= T/R = GND
Eight Bits Toggling
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
V
IN
= V
CC
V
IN
= GND
V
IN
= 3.4V
V
IN
= GND
—
0.6
2.2
mA
V
IN
= V
CC
V
IN
= GND
Test Conditions
(1)
Min.
—
—
Typ.
(2)
0.5
0.06
Max.
2
0.12
Unit
mA
mA/
MHz
—
0.9
3.2
—
1.2
3.4
(5)
—
3.2
11.4
(5)
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+ 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
= Output Frequency
N
i
= Number of Outputs at f
i
All currents are in milliamps and all frequencies are in megahertz.
4
IDT74FCT2245AT/CT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVER
INDUSTRIAL TEMPERATURE RANGE
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
(1)
74FCT2245AT
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)
1.5
5
1.5
4.8
ns
1.5
6.2
1.5
5.8
ns
1.5
5
1.5
4.8
ns
Condition
(1)
C
L
= 50 pF
R
L
= 500Ω
1.5
6.2
1.5
5.8
ns
Min
.
(2)
1.5
Max.
4.6
1.5
74FCT2245CT
Min
.
(2)
Max.
4.1
Unit
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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