
6.9
4
IDT54/74FCT245T/AT/CT/DT - 2245T/AT/CT, IDT54/74FCT640T/AT/CT, IDT54/74FCT645T/AT/CT/DT
FAST CMOS OCTAL BIDIRECTIONAL TRANSCEIVERS
MILITARY AND COMMERCIAL TEMPERATURE RANGES
POWER SUPPLY CHARACTERISTICS
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.
2539 tbl 08
Symbol
I
CC
Parameter
Test Conditions
(1)
Min.
—
Typ.
(2)
0.5
Max.
2.0
Unit
mA
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
V
CC
 = Max.
I
CCD
V
IN
 = V
CC
V
IN
 = GND
FCTxxxT
—
0.15
0.25
mA/
MHz
FCT2xxxT
—
0.06
0.12
I
C
Total Power Supply Current
(6)
V
IN
 = V
CC
FCTxxxT
—
1.5
3.5
mA
Outputs Open
fi = 10MHz
50% Duty Cycle
V
IN
 = GND FCT2xxxT
—
0.6
2.2
V
IN
 = 3.4
FCTxxxT
—
1.8
4.5
OE
 = T/
R
 = GND   
One Bit Toggling
V
CC
 = Max.
V
IN
 = GND FCT2xxxT
0.9
3.2
V
IN
 = V
CC
FCTxxxT
—
3.0
6.0
(5)
3.4
(5)
Outputs Open
fi = 2.5MHz
50% Duty Cycle
OE
 = T/
R
 = GND  
Eight Bits Toggling
V
IN
 = GND FCT2xxxT
—
1.2
V
IN
 = 3.4
V
IN
 = GND FCT2xxxT
FCTxxxT
—
—
5.0
3.2
14.0
(5)
11.4
(
5)