INDUSTRIALTEMPERATURERANGE

4

74FCT521AT/CT

FASTCMOS8-BITIDENTITYCOMPARATOR

Feb.11.20

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