54AC520 •54ACT520
8-Bit Identity Comparator
General Description
The ’AC/’ACT520 are expandable 8-bit comparators. They
compare two words of up to eight bits each and provide 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
nCompares two 8-bit words in 6.5 ns typ
nExpandable to any word length
n20-pin package
nOutputs source/sink 24 mA
n’ACT520 has TTL-compatible inputs
nStandard Microcircuit Drawing (SMD)
54AC520: 5962-90916
54ACT520: 5962-89793
Logic Symbols
Pin Names Description
A
0
–A
7
Word A Inputs
B
0
–B
7
Word B Inputs
T
A=B
Expansion or Enable Input
O
A=B
Identity Output
FACT™is a trademark of Fairchild Semiconductor Corporation.
DS100234-1
IEEE/IEC
DS100234-4
September 1998
54AC520
•
54ACT520 8-Bit Identity Comparator
© 2001 National Semiconductor Corporation DS100234 www.national.com
Connection Diagrams
Inputs Outputs
I
A=B
A, B O
A=B
L A=B
*L
LA
≠
BH
H A=B
*H
HA
≠
BH
H = HIGH Voltage Level
L = LOW Voltage Level
*A0=B
0
,A
1=B
1
,A
2=B
2
, etc.
Pin Assignment
for DIP and Flatpak
DS100234-2
Pin Assignment
for LCC
DS100234-3
54AC520
•
54ACT520
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Logic Diagram
DS100234-5
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
54AC520
•
54ACT520
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Absolute Maximum Ratings (Note 1)
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 V
CC
+ 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 V
CC
+ 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 (V
CC
)
’AC 2.0V to 6.0V
’ACT 4.5V to 5.5V
Input Voltage (V
I
) 0VtoV
CC
Output Voltage (V
O
) 0VtoV
CC
Operating Temperature (T
A
)
54AC/ACT −55˚C to +125˚C
Minimum Input Edge Rate (∆V/∆t)
’AC Devices
V
IN
from 30% to 70% of V
CC
V
CC
@3.3V, 4.5V, 5.5V 125 mV/ns
Minimum Input Edge Rate (∆V/∆t)
’ACT Devices
V
IN
from 0.8V to 2.0V
V
CC
@4.5V, 5.5V 125 mV/ns
Note 1: 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, and output/input loading variables. National does not recom-
mend operation of FACT™circuits outside databook specifications.
DC Characteristics for ’AC Family Devices
54AC
Symbol Parameter V
CC
T
A
= Units Conditions
(V) −55˚C to +125˚C
Guaranteed Limits
V
IH
Minimum High Level 3.0 2.1 V
OUT
= 0.1V
Input Voltage 4.5 3.15 V or V
CC
− 0.1V
5.5 3.85
V
IL
Maximum Low Level 3.0 0.9 V
OUT
= 0.1V
Input Voltage 4.5 1.35 V or V
CC
− 0.1V
5.5 1.65
V
OH
Minimum High Level 3.0 2.9 I
OUT
= −50 µA
Output Voltage 4.5 4.4 V
5.5 5.4 (Note 2)
V
IN
=V
IL
or V
IH
3.0 2.4 I
OH
= −12 mA
4.5 3.7 V I
OH
= −24 mA
5.5 4.7 I
OH
= −24 mA
V
OL
Maximum Low Level 3.0 0.1 I
OUT
=50µA
Output Voltage 4.5 0.1 V
5.5 0.1 (Note 2)
V
IN
=V
IL
or V
IH
3.0 0.50 I
OL
=12mA
4.5 0.50 V I
OL
=24mA
5.5 0.50 I
OL
=24mA
I
IN
Maximum Input 5.5 ±1.0 µA V
I
=V
CC
, GND
Leakage Current A Inputs Only
I
IH
Maximum Input 5.5 20.0 µA V
I
=V
CC
High Leakage Current B Inputs Only
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•
54ACT520
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DC Characteristics for ’AC Family Devices (Continued)
54AC
Symbol Parameter V
CC
T
A
= Units Conditions
(V) −55˚C to +125˚C
Guaranteed Limits
I
IL
Maximum Input 5.5 −1.5 mA V
I
=V
CC
Low Leakage Current B Inputs Only
I
OLD
Minimum Dynamic
(Note 3) 5.5 50 mA V
OLD
= 1.65V Max
I
OHD
Output Current 5.5 −50 mA V
OHD
= 3.85V Min
I
CC
Maximum Quiescent 5.5 80.0 µA V
IN
=V
CC
Supply Current
I
CC
Maximum Quiescent 5.5 8.0 mA V
IN
= GND
Supply Current
Note 2: All outputs loaded; thresholds on input associated with output under test.
Note 3: Maximum test duration 2.0 ms, one output loaded at a time.
DC Characteristics for ’ACT Family Devices
54ACT
Symbol Parameter V
CC
T
A
= Units Conditions
(V) −55˚C to +125˚C
Guaranteed Limits
V
IH
Minimum High Level 4.5 2.0 V V
OUT
= 0.1V
Input Voltage 5.5 2.0 or V
CC
− 0.1V
V
IL
Maximum Low Level 4.5 0.8 V V
OUT
= 0.1V
Input Voltage 5.5 0.8 or V
CC
− 0.1V
V
OH
Minimum High Level 4.5 4.4 V I
OUT
= −50 µA
Output Voltage 5.5 5.4 (Note 4)
V
IN
=V
IL
or V
IH
4.5 3.70 V I
OH
= −24 mA
5.5 4.70 I
OH
= −24 mA
V
OL
Maximum Low Level 4.5 0.1 V I
OUT
=50µA
Output Voltage 5.5 0.1 (Note 4)
V
IN
=V
IL
or V
IH
4.5 0.50 V I
OL
=24mA
5.5 0.50 I
OL
=24mA
I
IN
Maximum Input 5.5 ±1.0 µA V
I
=V
CC
, GND
Leakage Current
I
IH
Maximum Input 5.5 10.0 µA V
I
=V
CC
High Leakage Current B Inputs Only
I
IL
Maximum Input 5.5 −1.0 mA V
I
=V
CC
Low Leakage Current B Inputs Only
I
CCT
Maximum 5.5 1.6 mA V
I
=V
CC
− 2.1V
I
CC
/Input
I
OLD
Minimum Dynamic
(Note 5) 5.5 50 mA V
OLD
= 1.65V Max
I
OHD
Output Current 5.5 −50 mA V
OHD
= 3.85V Min
I
CC
Maximum Quiescent 5.5 80.0 µA V
IN
=V
CC
Supply Current or GND
54AC520
•
54ACT520
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DC Characteristics for ’ACT Family Devices (Continued)
54ACT
Symbol Parameter V
CC
T
A
= Units Conditions
(V) −55˚C to +125˚C
Guaranteed Limits
I
CC
Maximum Quiescent 5.5 8.0 mA V
IN
= GND
Supply Current
Note 4: All outputs loaded; thresholds on input associated with output under test.
Note 5: Maximum test duration 2.0 ms, one output loaded at a time.
AC Electrical Characteristics
54AC
V
CC
T
A
= −55˚C Fig.
Symbol Parameter (V) to +125˚C Units No.
(Note 6) C
L
=50pF
Min Max
t
PLH
Propagation Delay 3.3 1.0 14.0 ns
A
n
or B
n
to O
A=B
5.0 1.5 10.5
t
PHL
Propagation Delay 3.3 1.0 15.0 ns
A
n
or B
n
to O
A=B
5.0 1.5 11.0
t
PLH
Propagation Delay 3.3 1.0 10.0 ns
I
A=B
to O
A=B
5.0 1.5 7.5
t
PHL
Propagation Delay 3.3 1.0 10.5 ns
I
A=B
to O
A=B
5.0 1.5 8.0
Note 6: Voltage Range 3.3 is 3.3V ±0.3V
Voltage Range 5.0 is 5.0V ±0.5V
AC Electrical Characteristics
54ACT
V
CC
T
A
= −55˚C Fig.
Symbol Parameter (V) to +125˚C Units No.
(Note 7) C
L
=50pF
Min Max
t
PLH
Propagation Delay 5.0 1.5 12.0 ns
A
n
or B
n
to O
A=B
t
PHL
Propagation Delay 5.0 1.5 12.0 ns
A
n
or B
n
to O
A=B
t
PLH
Propagation Delay 5.0 1.5 8.5 ns
I
A=B
to O
A=B
t
PHL
Propagation Delay 5.0 1.5 9.0 ns
I
A=B
to O
A=B
Note 7: Voltage Range 5.0 is 5.0V ±0.5V
Capacitance
Symbol Parameter Typ Units Conditions
C
IN
Input Capacitance 4.5 pF V
CC
= OPEN
C
PD
Power Dissipation Capacitance 40 pF V
CC
= 5.0V
54AC520
•
54ACT520
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Applications
Ripple Expansion
DS100234-6
Parallel Expansion
DS100234-7
54AC520
•
54ACT520
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Physical Dimensions inches (millimeters) unless otherwise noted
20 Terminal Ceramic Leadless Chip Carrier (L)
NS Package Number E20A
20 Lead Ceramic Dual-In-Line Package (D)
NS Package Number J20A
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54ACT520
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
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20 Lead Ceramic Flatpak (F)
NS Package Number W20A
54AC520
•
54ACT520 8-Bit Identity Comparator
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
