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54AC521 • 54ACT521 8-Bit Identity Comparator
September 1998
54AC521 • 54ACT521 8-Bit Identity Comparator
General Description
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.
Features
n n n n n n ICC reduced by 50% Compares two 8-bit words in 6.5 ns typ Expandable to any word length Outputs source/sink 24 mA ACT521 has TTL-compatible inputs Standard microcircuit Drawing (SMD) 54AC521: 5962-90985 54ACT521: 5962-89793
Logic Symbols
Connection Diagram
Pin Assignment for DIP and CERPACK
DS100291-1
IEEE/IEC
DS100291-2
Pin Assignment for LCC
DS100291-4
DS100291-3
Pin Descriptions
Pin Names A0–A7 B0–B7 TA = B OA = B Word A Inputs Word B Inputs Expansion or Enable Input Identity Output Description
FACT™ is a trademark of Fairchild Semiconductor Corporation.
© 1998 National Semiconductor Corporation
DS100291
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Truth Table
Inputs IA = B L L H H
H = HIGH Voltage Level L = LOW Voltage Level Note 1: A0 = B0, A1 = B1, A2 = B2, etc.
Outputs A, B OA = B L H H H
A = B (Note 1) A≠B A = B (Note 1) A≠B
Logic Diagram
DS100291-5
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 (VCC) DC Input Diode Current (IIK) VI = −0.5V VI = VCC + 0.5V DC Input Voltage (VI) DC Output Diode Current (IOK) VO = −0.5V VO = VCC + 0.5V DC Output Voltage (VO) DC Output Source or Sink Current (IO) DC VCC or Ground Current per Output Pin (ICC or IGND) Storage Temperature (TSTG) Junction Temperature (TJ) CDIP −0.5V to +7.0V −20 mA +20 mA −0.5V to VCC + 0.5V −20 mA +20 mA −0.5V to VCC + 0.5V
Recommended Operating Conditions
Supply Voltage (VCC) AC ACT Input Voltage (VI) Output Voltage (VO) Operating Temperature (TA) 54AC/ACT Minimum Input Edge Rate (∆V/∆t) AC Devices VIN from 30% to 70% of VCC VCC @ 3.3V, 4.5V, 5.5V Minimum Input Edge Rate (∆V/∆t) ACT Devices VIN from 0.8V to 2.0V VCC @ 4.5V, 5.5V 2.0V to 6.0V 4.5V to 5.5V 0V to VCC 0V to VCC −55˚C to +125˚C
125 mV/ns
± 50 mA ± 50 mA −65˚C to +150˚C
175˚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 Parameter Minimum High Level Input Voltage VIL Maximum Low Level Input Voltage VOH Minimum High Level Output Voltage VCC (V) 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 3.0 4.5 5.5 VOL Maximum Low Level Output Voltage 3.0 4.5 5.5 3.0 4.5 5.5 IIN (Note 5) IOLD IOHD ICC (Note 5) Maximum Input Leakage Current Minimum Dynamic Output Current (Note 4) Maximum Quiescent Supply Current 5.5 5.5 5.5 50 −50 80.0 mA mA µA VOLD = 1.65V Max VOHD = 3.85V Min VIN = V or GND
CC
TA = −55˚C to +125˚C Guaranteed Limits 2.1 3.15 3.85 0.9 1.35 1.65 2.9 4.4 5.4
Units
Conditions VOUT = 0.1V
V
or VCC − 0.1V VOUT = 0.1V
V
or VCC − 0.1V IOUT = −50 µA
V VIN = V or VIH
IL
2.4 3.7 4.7 0.1 0.1 0.1 V V
IOH = −4 mA IOH = −24 mA IOH = −24 mA (Note 3) IOUT = 50 µA
VIN = V 0.4 0.5 0.5 V µA
IL
or VIH
IOL = 12 mA IOL = 24 mA IOL = 24 mA (Note 3) VI = V
CC,
5.5
± 1.0
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.
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DC Electical Characteristics for ACT
Symbol VIH VIL VOH Parameter Minimum High Level Input Voltage Maximum Low Level Input Voltage Minimum High Level Output Voltage VCC (V) 4.5 5.5 4.5 5.5 4.5 5.5 4.5 5.5 VOL Maximum Low Level Output Voltage 4.5 5.5 4.5 5.5 IIN ICCT IOLD IOHD ICC Maximum Input Leakage Current Maximum ICC/Input Minimum Dynamic Output Current (Note 7) Maximum Quiescent Supply Current
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.
TA = −55˚C to +125˚C Guaranteed Limits 2.0 2.0 0.8 0.8 4.4 5.4
Units V V V
Conditions VOUT = 0.1V or VCC − 0.1V VOUT = 0.1V or VCC − 0.1V IOUT = −50 µA VIN = V or VIH
IL
3.7 4.7 0.1 0.1
V V
IOH = −24 mA IOH = −24 mA (Note 6) IOUT = 50 µA VIN = V or VIH
IL
0.5 0.5
V µA mA mA mA µA
IOL = 24 mA IOL = 24 mA (Note 6) VI = V VI = V
CC,
5.5 5.5 5.5 5.5 5.5
± 1.0
1.5 50 −50 80.0
GND − 2.1V
CC
VOLD = 1.65V Max VOHD = 3.85V Min .