|
Details, datasheet, quote on part number:JM38510/31101SF
| |
Datasheet text preview:
54LS85 DM54LS85 DM74LS85 4-Bit Magnitude Comparators
June 1989
54LS85 DM54LS85 DM74LS85 4-Bit Magnitude Comparators
General Description
These 4-bit magnitude comparators perform comparison of straight binary or BCD codes Three fully-decoded decisions about two 4-bit words (A B) are made and are externally available at three outputs These devices are fully expandable to any number of bits without external gates Words of greater length may be compared by connecting comparators in cascade The A l B A k B and A e B outputs of a stage handling less-significant bits are connected to the corresponding inputs of the next stage handling more-significant bits The stage handling the least-significant bits must C have a high-level voltage applied to the A e B input The cascading path is implemented with only a two-gate-level delay to reduce overall comparison times for long words F
eatures
Y Y Y
Typical power dissipation 52 mW Typical delay (4-bit words) 24 ns Alternate Military Aerospace device (54LS85) is availD able Contact a National Semiconductor Sales Office istributor for specifications
onnection Diagram
Dual-In-Line Package
Order Number 54LS85DMQB 5 4LS85FMQB 54LS85LMQB DM54LS85J DM54LS85W DM74LS85M or DM74LS85N See NS Package Number E20A J 16A M16A N16E or W16A
TL F 6379 1
Function Table
Comparing Inputs A3 B3 A3 l B3 A3 k B3 A3 A3 A3 A3 A3 A3 A3 A3 A3 A3 A3 A3
e e e e e e e e e e e e
Cascading Inputs A0 B0 X X X X X X A0 l B0 A0 k B0 A0 e B0 A0 e B0 A0 e B0 A0 e B0 A0 e B0 A0 e B0 AlB X X X X X X X X H L L X H L AkB X X X X X X X X L H L X H L AeB X X X X X X X X L L H H L L AlB H L H L H L H L H L L L L H
Outputs AkB L H L H L H L H L H L L L H AeB L L L L L L L L L L H H L L
A2 B2 X X A2 l B2 A2 k B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2 A2 e B2
A1 B1 X X X X A1 l B1 A1 k B1 A1 e B1 A1 e B1 A1 e B1 A1 e B1 A1 e B1 A1 e B1 A1 e B1 A1 e B1
B3 B3 B3 B3 B3 B3 B3 B3 B3 B3 B3 B3
H e High Level L e Low Level X e Don't Care
C1995 National Semiconductor Corporation TL F 6379 RRD-B30M105 Printed in U S A
Absolute Maximum Ratings (Note)
p If Military Aerospace specified devices are required lease contact the National Semiconductor Sales S Office Distributors for availability and specifications upply Voltage Input Voltage 7V 7V Note The ``Absolute Maximum Ratings'' are those values beyond which the safety of the device cannot be guaranteed The device should not be operated at these limits The parametric values defined in the ``Electrical Characteristics'' table are not guaranteed at the absolute maximum ratings T he ``Recommended Operating Conditions'' table will define the conditions for actual device operation
Operating Free Air Temperature Range R b 55 C to a 125 C DM54LS and 54LS DM74LS 0 C to a 70 C Storage Temperature Range
b 65
C to a 150 C
ecommended Operating Conditions
Symbol VCC VIH VIL IOH IOL TA Parameter Min Supply Voltage High Level Input Voltage Low Level Input Voltage High Level Output Current Low Level Output Current Free Air Operating Temperature
b 55
DM54LS85 Nom 5 Max 55 Min 4 75 2 07
b0 4
DM74LS85 Nom 5 Max 5 25
Units V V 08
b0 4
45 2
V mA mA
4 125 0
8 70
C
Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)
Symbol VI VOH Parameter Input Clamp Voltage High Level Output Voltage Low Level Output Voltage Conditions VCC e Min II e b18 mA VCC e Min IOH e Max VIL e Max VIH e Min VCC e Min IOL e Max VIL e Max VIH e Min IOL e 4 mA VCC e Min II Input Current Input Voltage
Max
Min
Typ (Note 1)
Max
b1 5
Units V V
DM54 DM74 DM54 DM74 DM74 AkB AlB Others
25 27
34 34 0 25 0 35 0 25 04 05 04 01 01 03 20 20 60
b0 4 b0 4 b1 2
VOL
V
VCC e Max VI e 7V
mA
IIH
High Level Input Current
VCC e Max VI e 2 7V
AkB AlB Others
mA
IIL
Low Level Input Current
VCC e Max VI e 0 4V
AkB AlB Others
mA
IOS
Short Circuit Output Current Supply Current
VCC e Max (Note 2) VCC e Max (Note 3)
DM54 DM74
b 20 b 20
b 100 b 100
mA mA
ICC
10
20
Note 1 All typicals are at VCC e 5V TA e 25 C Note 2 Not more than one output should be shorted at a time and the duration should not exceed one second ote 3 ICC is measured with all outputs open A e B grounded and all other inputs at 4 5V
2
Switching Characteristics at VCC e 5V and TA e 25 C (See Section 1 for Test Waveforms and Output Load)
Symbol Parameter From Input To Output Number of Gate Levels RL e 2 kX CL e 15 pF Min tPLH Propagation Delay Time Low-to-High Level Output Any A or B Data Input AkB AlB AeB tPHL Propagation Delay Time High-to-Low Level Output Any A or B Data Input AkB AlB AeB tPLH tPHL tPLH tPHL tPLH tPHL Propagation Delay Time Low-to-High Level Output Propagation Delay Time High-to-Low Level Output Propagation Delay Time Low-to-High Level Output Propagation Delay Time High-to-Low Level Output Propagation Delay Time Low-to-High Level Output Propagation Delay Time High-to-Low Level Output AkB or A e B AkB or A e B A eB AeB AlB or A e B AlB or A e B AlB AlB AeB AeB AkB AkB 3 4 3 4 1 1 2 2 1 1 Max 36 40 30 30 22 17 20 17 22 17 CL e 50 pF Min Max 42 40 40 40 26 26 25 26 26 26 ns ns ns ns ns ns ns ns Units
3
|
|
