
IDT54/74FCT821/823/824/825A/B/C
HIGH-PERFORMANCE CMOS BUS INTERFACE REGISTERS
MILITARY AND COMMERCIAL TEMPERATURE RANGES
7.19
5
POWER SUPPLY CHARACTERISTICS
V
LC
 = 0.2V; V
HC
 = V
CC
 – 0.2V
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.
2608 tbl 07
Symbol
Parameter
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Unit
I
CC
Quiescent Power Supply Current
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
 = 
EN
 = GND   
One Input Toggling
50% Duty Cycle
V
CC
 = Max.
Outputs Open
f
CP
 = 10MHz
50% Duty Cycle
OE
 = 
EN
 = GND   
One Bit Toggling
at f
    i
 = 5MHz
50% Duty Cycle
V
CC
 = Max.
Outputs Open
f
CP
 = 10MHz
50% Duty Cycle
OE
 = 
EN
 = GND  
Eight Bits Toggling  
at f
    i
 = 2.5MHz
50% Duty Cycle
—
0.2
1.5
mA
I
CC
Quiescent Power Supply Current
TTL Inputs HIGH
Dynamic Power Supply  
Current
(4)
—
0.5
2.0
mA
I
CCD
V
IN
≥
 V
HC
V
IN
≤
 V
LC
—
0.15
0.25
mA/
MHz
I
C
Total Power Supply Current
(6)
V
IN
≥
 V
HC
V
IN
≤
 V
LC
(FCT)
—
1.7
4.0
mA
V
IN
  = 3.4V
V
IN
  = GND
—
2.2
6.0
V
IN
≥
 V
HC
V
IN
≤
 V
LC
(FCT)
—
4.0
7.8
(5)
V
IN
 = 3.4V
V
IN
 = GND
—
6.2
16.8
(5)