3-line to 8-line decoders/demultiplexers (rev. e) ?· 3-line to 8-line decoders/demultiplexers ......

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  • SN54ALS138A, SN54AS138, SN74ALS138A, SN74AS1383-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS

    SDAS055E APRIL 1982 REVISED JULY 1996

    1POST OFFICE BOX 655303 DALLAS, TEXAS 75265

    Designed Specifically for High-SpeedMemory Decoders and Data TransmissionSystems

    Incorporate Three Enable Inputs to SimplifyCascading and/or Data Reception

    Package Options Include PlasticSmall-Outline (D) Packages, Ceramic ChipCarriers (FK), and Standard Plastic (N) andCeramic (J) 300-mil DIPs

    description

    The ALS138A and AS138 are 3-line to 8-linedecoders/demultiplexers designed for high-performance memory-decoding or data-routingapplications requiring very short propagationdelay times. In high-performance systems, thesedevices can be used to minimize the effects ofsystem decoding. When employed withhigh-speed memories with a fast enable circuit,the delay times of the decoder and the enable timeof the memory are usually less than the typicalaccess time of the memory. The effective systemdelay introduced by the Schottky-clamped systemdecoder is negligible.

    The conditions at the binary-select (A, B, and C)inputs and the three enable (G1, G2A, and G2B)inputs select one of eight output lines. Twoactive-low and one active-high enable inputsreduce the need for external gates or inverters when expanding. A 24-line decoder can be implemented withoutexternal inverters and a 32-line decoder requires only one inverter. An enable input can be used as a data inputfor demultiplexing applications.

    The SN54ALS138A and SN54AS138 are characterized for operation over the full military temperature rangeof 55C to 125C. The SN74ALS138A and SN74AS138 are characterized for operation from 0C to 70C.

    Copyright 1996, Texas Instruments IncorporatedPRODUCTION DATA information is current as of publication date.Products conform to specifications per the terms of Texas Instrumentsstandard warranty. Production processing does not necessarily includetesting of all parameters.

    SN54ALS138A, SN54AS138 . . . J PACKAGESN74ALS138A, SN74AS138 . . . D OR N PACKAGE

    (TOP VIEW)

    3 2 1 20 19

    9 10 11 12 13

    4

    5

    6

    7

    8

    18

    17

    16

    15

    14

    Y1Y2NCY3Y4

    CG2ANC

    G2BG1

    SN54ALS138A, SN54AS138 . . . FK PACKAGE(TOP VIEW)

    B A NC

    Y6

    Y5

    Y0

    Y7

    GN

    DN

    C

    NC No internal connection

    VC

    C

    1

    2

    3

    4

    5

    6

    7

    8

    16

    15

    14

    13

    12

    11

    10

    9

    ABC

    G2AG2B

    G1Y7

    GND

    VCCY0Y1Y2Y3Y4Y5Y6

    Please be aware that an important notice concerning availability, standard warranty, and use in critical applications ofTexas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

  • SN54ALS138A, SN54AS138, SN74ALS138A, SN74AS1383-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS

    SDAS055E APRIL 1982 REVISED JULY 1996

    2 POST OFFICE BOX 655303 DALLAS, TEXAS 75265

    FUNCTION TABLE

    INPUTSOUTPUTS

    ENABLE SELECTOUTPUTS

    G1 G2A G2B C B A Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7

    X H X X X X H H H H H H H H

    X X H X X X H H H H H H H H

    L X X X X X H H H H H H H H

    H L L L L L L H H H H H H H

    H L L L L H H L H H H H H H

    H L L L H L H H L H H H H H

    H L L L H H H H H L H H H H

    H L L H L L H H H H L H H H

    H L L H L H H H H H H L H H

    H L L H H L H H H H H H L H

    H L L H H H H H H H H H H L

    logic symbols (alternatives)

    BIN/OCT1

    1A

    22

    B

    43

    C

    4

    5

    6G1

    Y015

    0

    &

    EN

    Y114

    1

    Y213

    2

    Y312

    3

    Y411

    4

    Y510

    5

    Y69

    6

    Y77

    7

    DMUX0

    1A

    2B

    23

    C

    4

    5

    6G1

    Y015

    0

    &

    Y114

    1

    Y213

    2

    Y312

    3

    Y411

    4

    Y510

    5

    Y69

    6

    Y77

    7

    G 70

    G2A

    G2B

    G2A

    G2B

    These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.Pin numbers shown are for the D, J, and N packages.

  • SN54ALS138A, SN54AS138, SN74ALS138A, SN74AS1383-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS

    SDAS055E APRIL 1982 REVISED JULY 1996

    3POST OFFICE BOX 655303 DALLAS, TEXAS 75265

    logic diagram (positive logic)

    G2B

    G2A

    G1

    C

    B

    A

    Y7

    Y6

    Y5

    Y4

    Y3

    Y2

    Y1

    Y0

    DataOutputs

    SelectInputs

    EnableInputs

    1

    2

    3

    6

    4

    5

    15

    14

    13

    12

    11

    10

    9

    7

    Pin numbers shown are for the D, J, and N packages.

  • SN54ALS138A, SN54AS138, SN74ALS138A, SN74AS1383-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS

    SDAS055E APRIL 1982 REVISED JULY 1996

    4 POST OFFICE BOX 655303 DALLAS, TEXAS 75265

    absolute maximum ratings over operating free-air temperature range (unless otherwise noted)

    Supply voltage, VCC 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Input voltage, VI 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operating free-air temperature range, TA: SN54ALS138A 55C to 125C. . . . . . . . . . . . . . . . . . . . . . . . . . .

    SN74ALS138A 0C to 70C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage temperature range, Tstg 65C to 150C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

    Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, andfunctional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is notimplied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

    recommended operating conditions

    SN54ALS138A SN74ALS138AUNIT

    MIN NOM MAX MIN NOM MAXUNIT

    VCC Supply voltage 4.5 5 5.5 4.5 5 5.5 V

    VIH High-level input voltage 2 2 V

    VIL Low-level input voltage 0.7 0.8 V

    IOH High-level output current 0.4 0.4 mA

    IOL Low-level output current 4 8 mA

    TA Operating free-air temperature 55 125 0 70 C

    electrical characteristics over recommended operating free-air temperature range (unlessotherwise noted)

    PARAMETER TEST CONDITIONSSN54ALS138A SN74ALS138A

    UNITPARAMETER TEST CONDITIONSMIN TYP MAX MIN TYP MAX

    UNIT

    VIK VCC = 4.5 V, II = 18 mA 1.5 1.5 V

    VOH VCC = 4.5 V, IOH = 0.4 mA VCC 2 VCC 2 V

    VOL VCC = 4 5 VIOL = 4 mA 0.25 0.4 0.25 0.4

    VVOL VCC = 4.5 VIOL = 8 mA 0.35 0.5

    V

    II VCC = 5.5 V, VI = 7 V 0.1 0.1 mA

    IIH VCC = 5.5 V, VI = 2.7 V 20 20 A

    IIL VCC = 5.5 V, VI = 0.4 V 0.1 0.1 mA

    IO VCC = 5.5 V, VO = 2.25 V 20 112 30 112 mA

    ICC VCC = 5.5 V 5 10 5 10 mA

    All typical values are at VCC = 5 V, TA = 25C. The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.

    switching characteristics (see Figure 1)

    PARAMETERFROM

    (INPUT)TO

    (OUTPUT)

    VCC = 4.5 V to 5.5 V,CL = 50 pF,RL = 500 ,TA = MIN to MAX UNIT(INPUT) (OUTPUT)

    SN54ALS138A SN74ALS138A

    MIN MAX MIN MAX

    tPLHA B C Any Y

    2 28 5 22ns

    tPHLA, B, C Any Y

    6 22 6 18ns

    tPLHG or G Any Y

    2 22 3 17ns

    tPHLG or G Any Y

    4 21 4 17ns

    For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.

  • SN54ALS138A, SN54AS138, SN74ALS138A, SN74AS1383-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS

    SDAS055E APRIL 1982 REVISED JULY 1996

    5POST OFFICE BOX 655303 DALLAS, TEXAS 75265

    absolute maximum ratings over operating free-air temperature range (unless otherwise noted)

    Supply voltage, VCC 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Input voltage, VI 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operating free-air temperature range, TA: SN54AS138 55C to 125C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

    SN74AS138 0C to 70C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage temperature range, Tstg 65C to 150C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

    Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, andfunctional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is notimplied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

    recommended operating conditions

    SN54AS138 SN74AS138UNIT

    MIN NOM MAX MIN NOM MAXUNIT

    VCC Supply voltage 4.5 5 5.5 4.5 5 5.5 V

    VIH High-level input voltage 2 2 V

    VIL Low-level input voltage 0.8 0.8 V

    IOH High-level output current 2 2 mA

    IOL Low-level output current 20 20 mA

    TA Operating free-air temperature 55 125 0 70 C

    electrical characteristics over recommended operating free-air temperature range (unlessotherwise noted)

    PARAMETER TEST CONDITIONSSN54AS138 SN74AS138

    UNITPARAMETER TEST CONDITIONSM

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