NSC 5962-8854301RA, 5962-8854301SA, 5962-88543012A Datasheet
54FCT521
8-Bit Identity Comparator
General Description
The ’FCT521 is an expandable 8-bit comparator. It compares two words of up to eight bits each and provides a LOW
output when the two words match bit for bit. The expansion
input I
A=B
also serves as an active LOW enable input.
Features
n Expandable to any word length
n Outputs sink capability of 32mA, source capability of 12
mA
n TTL input and output level compatible
n CMOS power consumption
n Standard microcircuit Drawing (SMD) 5962-8854301
Logic Symbols Connection Diagram
Pin Descriptions
Pin Names Description
A
0–A7
Word A Inputs
B
0–B7
Word B Inputs
T
A=B
Expansion or Enable Input
O
A=B
Identity Output
FACT™is a trademark ofFairchild Semiconductor Corporation.
DS100968-1
IEEE/IEC
DS100968-4
Pin Assignment
for DIP and CERPACK
DS100968-2
Pin Assignment
for LCC
DS100968-3
September 1998
54FCT521 8-Bit Identity Comparator
© 1998 National Semiconductor Corporation DS100968 www.national.com
Truth Table
Inputs Outputs
I
A=B
A, B O
A=B
LA
=
B (Note 1) L
LA
≠
BH
HA
=
B (Note 1) H
HA
≠
BH
H
=
HIGH Voltage Level
L=LOW Voltage Level
Note 1: A
0
=
B
0,A1
=
B
1,A2
=
B
2
, etc.
Logic Diagram
DS100968-5
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
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Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
) −0.5V to +7.0V
DC Input Diode Current (I
IK
)
V
I
=
−0.5V −20 mA
V
I
=
V
CC
+ 0.5V +20 mA
DC Input Voltage (V
I
) −0.5V to VCC+ 0.5V
DC Output Diode Current (I
OK
)
V
O
=
−0.5V −20 mA
V
O
=
V
CC
+ 0.5V +20 mA
DC Output Voltage (V
O
) −0.5V to VCC+ 0.5V
DC Output Source
or Sink Current (I
O
)
±
50 mA
DC V
CC
or Ground Current
per Output Pin (I
CC
or I
GND
)
±
50 mA
Storage Temperature (T
STG
) −65˚C to +150˚C
Junction Temperature (T
J
)
CDIP 175˚C
Recommended Operating
Conditions
Supply Voltage (VCC)
FCT 4.5V to 5.5V
Input Voltage (V
I
) 0VtoV
CC
Output Voltage (VO) 0VtoV
CC
Operating Temperature (TA)
54FCT −55˚C to +125˚C
Note 2: Absolute maximum ratings are those values beyond which damage
to the device may occur. The databook specifications should be met, without
exception, to ensure that the system design is reliable over its power supply,
temperature, output/input loading variables. National does not recommend
operation of FACT
™
circuits outside databook specifications.
DC Electrical Characteristics for ’FCT Family Devices
Symbol Parameter 54FCT Units V
CC
Conditions
Min Max
V
IH
Input HIGH Voltage 2.0 V Recognized HIGH Signal
V
IL
Input LOW Voltage 0.8 V Recognized LOW Signal
V
CD
Input Clamp Diode Voltage −1.2 V Min I
IN
=
−18 mA
V
OH
Output HIGH Voltage 54FCT 4.3 V Min I
OH
=
−300 µA
54FCT 2.4 V Min I
OH
=
−12 mA
V
OL
Output LOW Voltage 54FCT 0.2 V Min I
OL
=
300 µA
54FCT 0.5 V Min I
OL
=
32 mA
I
IH
Input HIGH Current 5 µA Max V
IN
=
V
CC
I
IL
Input LOW Current −5 µA Max V
IN
=
0.0V
I
OS
Output Short-Circuit Current -60 mA Max V
OUT
=
0.0V
I
CCQ
Quiescent Power
Supply Current
1.5 mA Max V
IN
<
0.2V or VIN5.3V, VCC=
5.5V
∆I
CC
Quiescent Power
Supply Current
2.0 mA Max V
I
=
V
CC
− 2.1V
I
CCD
Dynamic I
CC
0.25 mA/
MHz
Max VCC= 5.5V, Outputs Open,
One Bit Toggling, 50%Duty
Cycle, OE
n
=
GND
I
CC
Total Power Supply
Current
5.0 mA Max VCC= 5.5V, Outputs Open, fI
= 10MHz, OE
n
=
GND, One
Bit Toggling, 50%Duty Cycle
Note 3: All outputs loaded; thresholds on input associated with output under test.
Note 4: Maximum test duration 2.0 ms, one output loaded at a time.
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