http://www.www.datasheet4u.com

900,000+ Datasheet PDF Search and Download

Datasheet4U offers most rated semiconductors datasheets pdf




Fairchild Semiconductor Electronic Components Datasheet

74138 Datasheet

Decoder/Demultiplexer

No Preview Available !

74138 pdf
August 1986
Revised March 2000
DM74LS138 • DM74LS139
Decoder/Demultiplexer
General Description
These Schottky-clamped circuits are designed to be used
in high-performance memory-decoding or data-routing
applications, requiring very short propagation delay times.
In high-performance memory systems these decoders can
be used to minimize the effects of system decoding. When
used with high-speed memories, the delay times of these
decoders are usually less than the typical access time of
the memory. This means that the effective system delay
introduced by the decoder is negligible.
The DM74LS138 decodes one-of-eight lines, based upon
the conditions at the three binary select inputs and the
three enable inputs. Two active-low and one active-high
enable inputs reduce the need for external gates or invert-
ers when expanding. A 24-line decoder can be imple-
mented with no external inverters, and a 32-line decoder
requires only one inverter. An enable input can be used as
a data input for demultiplexing applications.
The DM74LS139 comprises two separate two-line-to-four-
line decoders in a single package. The active-low enable
input can be used as a data line in demultiplexing applica-
tions.
All of these decoders/demultiplexers feature fully buffered
inputs, presenting only one normalized load to its driving
circuit. All inputs are clamped with high-performance
Schottky diodes to suppress line-ringing and simplify sys-
tem design.
Features
s Designed specifically for high speed:
Memory decoders
Data transmission systems
s DM74LS138 3-to-8-line decoders incorporates 3 enable
inputs to simplify cascading and/or data reception
s DM74LS139 contains two fully independent 2-to-4-line
decoders/demultiplexers
s Schottky clamped for high performance
s Typical propagation delay (3 levels of logic)
DM74LS138 21 ns
DM74LS139 21 ns
s Typical power dissipation
DM74LS138 32 mW
DM74LS139 34 mW
Ordering Code:
Order Number Package Number
Package Description
DM74LS138M
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74LS138SJ
M16D
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74LS138N
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74LS139M
M16A
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
DM74LS139SJ
M16D
16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74LS139N
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
© 2000 Fairchild Semiconductor Corporation DS006391
www.fairchildsemi.com


Fairchild Semiconductor Electronic Components Datasheet

74138 Datasheet

Decoder/Demultiplexer

No Preview Available !

74138 pdf
Connection Diagrams
DM74LS138
DM74LS139
Function Tables
DM74LS138
DM74LS139
Inputs
Enable
Select
Outputs
Inputs
Enable
Select
Outputs
G1 G2 (Note 1) C B A YO Y1 Y2 Y3 Y4 Y5 Y6 Y7
G B A Y0 Y1 Y2
X H XXX H H H H H H H H
H
XX
H
H
H
L X XXX H H H H H H H H
L
LL
L
H
H
H L LLL L H H H H H H H
L
LH
H
L
H
H L LLH H L H H H H H H
L
HL
H
H
L
H L LHL H H L H H H H H
L
HH
H
H
H
H L LHH H H H L H H H H
H L HLL H H H H L H H H
H L H L H H H H H H L H H H = HIGH Level
H
L
HH L H
HHHHH L H
L = LOW Level
X = Don’t Care
H L HHH H H H H H H H L
Note 1: G2 = G2A + G2B
Y3
H
H
H
H
L
Logic Diagrams
DM74LS138
DM74LS139
www.fairchildsemi.com
2


Part Number 74138
Description Decoder/Demultiplexer
Maker Fairchild Semiconductor
Total Page 7 Pages
PDF Download
74138 pdf
Download PDF File


Buy Electronic Components




Related Datasheet

1 7413 Power MOSFET(Vdss=30V/ Id=12A) International Rectifier
International Rectifier
7413 pdf
2 74130 Retriggerable Monostable Multivibrators Texas Instruments
Texas Instruments
74130 pdf
3 74131 1-of-8 inverting decoder/demultiplexer with address register ETC
ETC
74131 pdf
4 74132 Quad 2-Input NAND Gates National Semiconductor
National Semiconductor
74132 pdf
5 74134 12-input NAND gate ETC
ETC
74134 pdf
6 74135 Exclusive OR/NOR Gates ETC
ETC
74135 pdf
7 74138 LOW POWER SCHOTTKY ON Semiconductor
ON Semiconductor
74138 pdf
8 74138 Decoder/Demultiplexer Fairchild Semiconductor
Fairchild Semiconductor
74138 pdf
9 74139 T1/CEPT/ISDN-PRI Dual Transformer Bourns Electronic Solutions
Bourns Electronic Solutions
74139 pdf






Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

site map

webmaste! click here

contact us

Buy Components