
IDT54/74FCT521T/AT/BT/CT
FAST CMOS 8-BIT IDENTITY COMPARATOR
MILITARY AND COMMERCIAL TEMPERATURE RANGES
6.16
3
POWER SUPPLY CHARACTERISTICS
Symbol
Quiescent Power Supply  
Current TTL
Inputs HIGH
I
CCD
Dynamic Power Supply Current
(4)
2572 tbl 06
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
CC
V
CC
 = Max.
V
IN 
= 3.4V
(3)
—
0.5
2.0
mA
V
CC
 = Max.
Outputs Open
One Input Toggling
50% Duty Cycle
V
CC
 = Max.
Outputs Open
fi = 10MHz
One Bit Toggling
50% Duty Cycle
V
IN
 = V
CC 
V
IN
 = GND
—
0.15
0.25
mA/
MHz
I
C
Total Power Supply Current
(5)
V
IN
  = V
CC 
V
IN
  = GND
V
IN
  = 3.4V
V
IN
  = GND
—
1.5
3.5
mA
—
1.8
4.5
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.
SWITCHING CHARACTERISTICS OVER OPERATING RANGE
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
2572 tbl 07
IDT54/74FCT521T
IDT54/74FCT521AT
IDT54/74FCT521BT
IDT54/74FCT521CT
Com'l.
Mil.
Com'l.
Mil.
Com'l.
Mil.
Com'l.
Mil.
Symbol
t
PLH
t
PHL
Parameter
Propagation  
Delay
An or Bn to
O
A
 = 
B
Propagation  
Delay
I
A
 = 
B
 to  
O
A
 = 
B
Condition
(1)Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max. Min.
(2)
Max.
 Unit
CL = 50pF
RL = 500
1.5 11.0 1.5 15.0 1.5
7.2
1.5
9.5
1.5
5.5
1.5
7.3
1.5
4.5
1.5
5.1
ns
t
PLH
t
PHL
1.5 10.0 1.5
9.0
1.5
6.0
1.5
7.8
1.5
4.6
1.5
6.0
1.5
4.1
1.5
4.5
ns