FAIRCHILD 74ACT521SC

Revised November 1999
74AC521 • 74ACT521
8-Bit Identity Comparator
General Description
Features
The AC/ACT521 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 IA = B also serves as an active LOW enable
input.
■ ICC reduced by 50%
■ Compares two 8-bit words in 6.5 ns typ
■ Expandable to any word length
■ 20-pin package
■ Outputs source/sink 24 mA
■ ACT521 has TTL-compatible inputs
Ordering Code:
Order Number
Package Number
74AC521SC
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
Package Description
74AC521SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74AC521PC
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
74ACT521SC
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
74ACT521SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74ACT521PC
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering table.
Logic Symbols
Connection Diagram
IEEE/IEC
Pin Descriptions
Pin Names
Description
A0–A7
Word A Inputs
B0–B7
Word B Inputs
TA = B
Expansion or Enable Input
OA = B
Identity Output
FACT is a trademark of Fairchild Semiconductor Corporation.
© 1999 Fairchild Semiconductor Corporation
DS009964
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74AC521 • 74ACT521 8-Bit Identity Comparator
November 1988
74AC521 • 74ACT521
Truth Table
Logic Diagram
Inputs
Outputs
A, B
IA = B
OA = B
L
A = B (Note 1)
L
L
A≠Β
H
H
A = B (Note 1)
H
H
A≠Β
H
H = HIGH Voltage Level
L = LOW Voltage Level
Note 1: A0 = B0, A1 = B1, A2 = B2, etc.
Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.
Applications
Ripple Expansion
Parallel Expansion
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2
Recommended Operating
Conditions
−0.5V to +7.0V
Supply Voltage (VCC)
DC Input Diode Current (IIK)
VI = −0.5V
−20 mA
VI = VCC + 0.5V
+20 mA
DC Input Voltage (VI)
Supply Voltage (VCC)
−0.5V to VCC + 0.5V
DC Output Diode Current (IOK)
VO = −0.5V
−20 mA
VO = VCC + 0.5V
+20 mA
DC Output Voltage (VO)
4.5V to 5.5V
0V to VCC
Output Voltage (VO)
0V to VCC
−40°C to +85°C
Operating Temperature (TA)
Minimum Input Edge Rate (∆V/∆t)
−0.5V to VCC + 0.5V
AC Devices
VIN from 30% to 70% of VCC
±50 mA
VCC @ 3.3V, 4.5V, 5.5V
DC VCC or Ground Current
125 mV/ns
Minimum Input Edge Rate (∆V/∆t)
±50 mA
per Output Pin (ICC or IGND)
Storage Temperature (TSTG)
2.0V to 6.0V
ACT
Input Voltage (VI)
DC Output Source
or Sink Current (IO)
AC
ACT Devices
−65°C to +150°C
VIN from 0.8V to 2.0V
Junction Temperature (TJ)
VCC @ 4.5V, 5.5V
PDIP
140°C
125 mV/ns
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. Fairchild does not recommend operation of FACT circuits outside databook specifications.
DC Electrical Characteristics for AC
Symbol
VIH
VIL
VOH
Parameter
TA = +25°C
VCC
TA = −40°C to +85°C
(V)
Typ
Guaranteed Limits
Minimum HIGH Level
3.0
1.5
Input Voltage
4.5
2.25
3.15
3.15
5.5
2.75
3.85
3.85
2.1
Units
Maximum LOW Level
3.0
1.5
0.9
0.9
Input Voltage
4.5
2.25
1.35
1.35
5.5
2.75
1.65
1.65
Minimum HIGH Level
3.0
2.99
2.9
2.9
Output Voltage
4.5
4.49
4.4
4.4
5.5
5.49
5.4
5.4
3.0
2.56
2.46
4.5
3.86
3.76
5.5
4.86
4.76
Conditions
VOUT = 0.1V
2.1
V
or VCC − 0.1V
VOUT = 0.1V
V
or VCC − 0.1V
V
IOUT = −50 µA
VIN = V IL or VIH
VOL
Maximum LOW Level
3.0
0.002
0.1
0.1
Output Voltage
4.5
0.001
0.1
0.1
5.5
0.001
0.1
0.1
3.0
0.36
0.44
4.5
0.36
0.44
5.5
0.36
0.44
5.5
±0.1
IOH = −12 mA
V
IOH = −24 mA
IOH = −24 mA (Note 3)
V
IOUT = 50 µA
VIN = V IL or VIH
IOL = 12 mA
V
IOL = 24 mA
IOL = 24 mA (Note 3)
IIN
Maximum Input
(Note 5)
Leakage Current
±1.0
µA
VI = V CC, GND
IOLD
Minimum Dynamic
5.5
75
mA
VOLD = 1.65V Max
IOHD
Output Current (Note 4)
5.5
−75
mA
ICC
Maximum Quiescent
(Note 5)
Supply Current
5.5
4.0
40.0
µA
VOHD = 3.85V Min
VIN = V CC
or GND
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.
Note 5: IIN and ICC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V VCC.
3
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74AC521 • 74ACT521
Absolute Maximum Ratings(Note 2)
74AC521 • 74ACT521
DC Electrical Characteristics for ACT
Symbol
VIH
VIL
VOH
Parameter
TA = +25°C
VCC
(V)
Typ
TA = −40°C to +85°C
Units
Conditions
Guaranteed Limits
Minimum HIGH Level
4.5
1.5
2.0
2.0
Input Voltage
5.5
1.5
2.0
2.0
Maximum LOW Level
4.5
1.5
0.8
0.8
Input Voltage
5.5
1.5
0.8
0.8
Minimum HIGH Level
4.5
4.49
4.4
4.4
Output Voltage
5.5
5.49
5.4
5.4
3.86
3.76
V
V
VOUT = 0.1V
or VCC − 0.1V
VOUT = 0.1V
or VCC − 0.1V
V
IOUT = −50 µA
V
IOH = −24 mA
VIN = V IL or VIH
4.5
5.5
VOL
IOH = −24 mA (Note 6)
4.86
4.76
Maximum LOW Level
4.5
0.001
0.1
0.1
Output Voltage
5.5
0.001
0.1
0.1
4.5
0.36
0.44
5.5
0.36
0.44
5.5
±0.1
±1.0
µA
VI = V CC, GND
1.5
mA
VI = V CC − 2.1V
VOLD = 1.65V Max
V
IOUT = 50 µA
V
IOL = 24 mA
VIN = V IL or VIH
IIN
Maximum Input
Leakage Current
ICCT
Maximum
5.5
ICC/Input
0.6
IOL = 24 mA (Note 6)
IOLD
Minimum Dynamic
5.5
75
mA
IOHD
Output Current (Note 7)
5.5
−75
mA
ICC
Maximum Quiescent
Supply Current
5.5
4.0
µA
40.0
VOHD = 3.85V Min
VIN = V CC
or GND
Note 6: All outputs loaded; thresholds on input associated with output under test.
Note 7: Maximum test duration 2.0 ms, one output loaded at a time.
AC Electrical Characteristics for AC
Symbol
tPLH
tPHL
tPLH
tPHL
Parameter
VCC
TA = +25°C
(V)
CL = 50 pF
TA = −40°C to +85°C
CL = 50 pF
(Note 8)
Min
Typ
Max
Min
Max
Propagation Delay
3.3
3.5
7.0
11.0
3.0
12.0
An or Bn to OA = B
5.0
2.5
5.0
8.0
2.0
9.0
Propagation Delay
3.3
4.5
7.5
11.5
3.5
12.5
An or Bn to OA = B
5.0
3.0
5.5
8.5
2.5
9.0
Propagation Delay
3.3
3.0
5.5
8.0
2.5
9.0
IA = B to OA = B
5.0
2.5
4.0
6.0
2.0
7.0
Propagation Delay
3.3
3.0
5.5
8.0
2.5
9.0
IA = B to OA = B
5.0
2.0
4.0
6.0
2.0
7.0
Note 8: Voltage Range 3.3 is 3.3V ± 0.3V
Voltage Range 5.0 is 5.0V ± 0.5V
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4
Units
ns
ns
ns
ns
Symbol
tPLH
Parameter
Propagation Delay
An or Bn to OA = B
tPHL
Propagation Delay
An or Bn to OA = B
tPLH
Propagation Delay
IA = B to OA = B
tPHL
Propagation Delay
IA = B to OA = B
VCC
TA = +25°C
(V)
CL = 50 pF
TA = −40°C to +85°C
CL = 50 pF
Units
(Note 9)
Min
Typ
Max
Min
Max
5.0
3.0
5.5
9.0
2.5
9.5
ns
5.0
3.0
6.0
10.0
2.5
11.0
ns
5.0
2.0
4.0
6.5
2.0
7.0
ns
5.0
2.5
5.0
7.5
2.0
8.0
ns
Note 9: Voltage Range 5.0 is 5.0V ± 0.5V
Capacitance
Typ
Units
CIN
Symbol
Input Capacitance
Parameter
4.5
pF
VCC = OPEN
CPD
Power Dissipation Capacitance
40
pF
VCC = 5.0V
5
Conditions
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74AC521 • 74ACT521
AC Electrical Characteristics for ACT
74AC521 • 74ACT521
Physical Dimensions inches (millimeters) unless otherwise noted
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300” Wide Body
Package Number M20B
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6
74AC521 • 74ACT521
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
Package Number M20D
7
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74AC521 • 74ACT521 8-Bit Identity Comparator
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300” Wide
Package Number N20A
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in 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
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which, (a) are intended for surgical implant into the
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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.
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