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查询DM74ALS521供应商
DM74ALS520 • DM74ALS521
8-Bit Comparator
DM74ALS520 • DM74ALS521 8-Bit Comparator
September 1986
Revised April 2000
General Description
These comparators per form an “equal to” comparison of
two 8-bit words with provision for expansion or external
enabling. The matc hing of the two 8-bit input plus a logic
LOW on the EN
DM74ALS520 and DM74ALS521. The DM74ALS520 and
DM74ALS521 have totem pole outputs for wire AND cascading. Additionally, the DM74ALS520 is provided with B
input pull up termination resistors for analog or switch data.
input produces t he output A = B on the
Features
■ Switching specifications at 50 pF
■ Switching specifications guaranteed over full tempera-
ture and V
■ Advanced oxide-isolated, ion-implanted Schottky TTL
process
■ Functionally and pin for pin compatible with LS fam ily
counterpart
■ Improved output transient handling capability
CC
range
Ordering Code:
Ordering Code Package Number Package Description
DM74ALS520WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74ALS520N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74ALS521WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
SM74ALS521N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also availab l e in Tape and Reel. Specify by appending th e s uffix let t er “X” to the ordering code.
Connection Diagram Function Table
Inputs Output
EN
LA = BL
LA ≠ BH
H = HIGH Logic Level
L = LOW Logic Level
X = Don't Care
HXH
Data A = B
© 2000 Fairchild Semiconductor Corporation DS006114 www.fairchildsemi.com
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Logic Diagram
DM74ALS520 • DM74ALS521
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Absolute Maximum Ratings(Note 1)
Supply Voltage 7V
Input Voltage 7V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range −65°C to +150°C
Typical θ
JA
N Package 62.0°C/W
M Package 82.0°C/W
Note 1: The “Absolute Maximum Ratings” are those value s beyond which
the safety of the d evice cannot b e guaranteed . The device sh ould not be
operated at these limit s. The parametric values defi ned in the Electrical
Characteristics tables are not gu aranteed at the absolute m ax imum ratings .
The “Recomm ended O peratin g Cond itions ” table will defin e the condition s
for actual device operation.
Recommended Operating Conditions
Symbol Parameter Min Nom Max Units
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Supply Voltage 4.5 5 5.5 V
HIGH Level Input Voltage 2 V
LOW Level In put Voltage 0.8 V
HIGH Level Output Current −2.6 mA
LOW Level Output Current 24 mA
Free Air Operating Temperature 0 70 °C
Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at V
Symbol Parameter Conditions Min Typ Max Units
V
IK
V
OH
V
OL
I
I
I
IH
I
IL
I
O
I
CC
Note 2: ICC is measured with EN groun ded, A and B inputs at 4.5V and outputs OPEN .
Input Clamp Voltage VCC = 4.5V, II = −18 mA −1.5 V
HIGH Level VCC = 4.5V to 5.5V
Output Voltage I
LOW Level Output Voltage VCC = 4.5V IOL = 24 mA 0.35 0.5 V
Max HIGH VCC = 5.5V VIH = 5.5V
Input Current B Input DM74ALS520 0.1 mA
HIGH Level VCC = 5.5V, All Others 20
Input Current V
Low Level Input VCC = 5.5V, B Input DM74ALS520 −0.6 mA
Current V
Output Drive Current VCC = 5.5V VO = 2.25V −30 −112 mA
Supply Current VCC = 5.5V (Note 2) 12 19 mA
= −400 µA
OH
V
= 4.5V
CC
= Max
I
OH
= 7V, All Others
V
IH
= 2.7V B Input DM74ALS520 −200
IH
= 0.4V All Others −0.1 mA
IL
= 5V, T
CC
= 25°C.
A
V
− 2V
CC
2.4 3.2 V
DM74ALS520 • DM74ALS521
µA
Switching Characteristics
over recommended operating free air temperature range
Symbol Parameter Conditions
t
PLH
t
PHL
t
PLH
t
PHL
Propagation Delay Time VCC = 4.5V to 5.5V A or B
LOW-to-HIGH Level Output CL = 50 pF Data
Propagation Delay Time RL = 500Ω A or B
HIGH-to-LOW Level Output Data
Propagation Delay Time
LOW-to-HIGH Level Output
Propagation Delay Time
HIGH-to-LOW Level Output
From To
Input Output
A = B 312ns
A = B 520ns
EN A = B 212ns
EN A = B 522ns
Min Max Units
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Physical Dimensions inches (millimeters) unless otherwise noted
DM74ALS520 • DM74ALS521
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
Package Number M20B
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
DM74ALS520 • DM74ALS521 8-Bit Comparator
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
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.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are dev ic es or syste ms
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provide d in the l abe ling, can be reasonably expected to result in a significant injury to the
user.
Package Number N20A
2. A critical compo nent in any com ponen t of a life s upp ort
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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