INDUSTRIALTEMPERATURERANGE
4
IDT74FCT521AT/CT
FASTCMOS8-BITIDENTITYCOMPARATOR
Symbol
Parameter
Test Conditions(1)
Min.
Typ.(2)
Max.
Unit
ΔICC
Quiescent Power Supply Current
VCC = Max.
—
0.5
2
mA
TTL Inputs HIGH
VIN = 3.4V(3)
ICCD
Dynamic Power Supply
VCC = Max.
VIN = VCC
—
0.15
0.25
mA/
Current(4)
Outputs Open
VIN = GND
MHz
One Input Toggling
50% Duty Cycle
IC
Total Power Supply Current(6)
VCC = Max.
VIN = VCC
—
1.5
3.5
mA
Outputs Open
VIN = GND
fi = 10MHz
VIN = 3.4V
—
1.8
4.5
One Bit Toggling
VIN = GND
50% Duty Cycle
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 VCC = 5.0V, +25°C ambient.
3. Per TTL driven input; (VIN = 3.4V). All other inputs at VCC 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
ΔICC formula. These limits are guaranteed but not tested.
6. IC = IQUIESCENT + IINPUTS + IDYNAMIC
IC = ICC +
ΔICC DHNT + ICCD (fCP/2+ fiNi)
ICC = Quiescent Current
ΔICC = Power Supply Current for a TTL High Input (VIN = 3.4V)
DH = Duty Cycle for TTL Inputs High
NT = Number of TTL Inputs at DH
ICCD = Dynamic Current caused by an Input Transition Pair (HLH or LHL)
fCP = Clock Frequency for Register Devices (Zero for Non-Register Devices)
fi = Output Frequency
Ni = Number of Outputs at fi
All currents are in milliamps and all frequencies are in megahertz.
POWER SUPPLY CHARACTERISTICS
NOTES:
1. See test circuit and waveforms.
2. Minimum limits are guaranteed but not tested on Propagation Delays.
74FCT521AT
74FCT521CT
Symbol
Parameter
Condition(1)
Min.(2)
Max.
Min.(2)
Max.
Unit
tPLH
PropagationDelay
CL = 50pF
1.5
7.2
1.5
4.5
ns
tPHL
Ax or Bx to
OA = B
RL = 500
Ω
tPLH
PropagationDelay
1.5
6
1.5
4.1
ns
tPHL
IA = B to OA = B
SWITCHING CHARACTERISTICS OVER OPERATING RANGE