Please enter a valid full or partial manufacturer part number with a minimum of 3 letters or numbers

    SN74ALS688DW Search Results

    SN74ALS688DW Result Highlights (3)

    Part ECAD Model Manufacturer Description Download Buy
    SN74ALS688DWG4 Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Visit Texas Instruments Buy
    SN74ALS688DWR Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Visit Texas Instruments
    SN74ALS688DW Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Visit Texas Instruments Buy
    SF Impression Pixel

    SN74ALS688DW Price and Stock

    Rochester Electronics LLC SN74ALS688DWR

    SN74ALS688 8-BIT IDENTITY/MAGNIT
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74ALS688DWR Bulk 5,693 88
    • 1 -
    • 10 -
    • 100 $3.44
    • 1000 $3.44
    • 10000 $3.44
    Buy Now

    Texas Instruments SN74ALS688DW

    IC COMPARATOR IDENTITY 8B 20SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74ALS688DW Tube 100
    • 1 -
    • 10 -
    • 100 $5.7853
    • 1000 $5.7853
    • 10000 $5.7853
    Buy Now
    Newark SN74ALS688DW Bulk 1
    • 1 $7.95
    • 10 $7.59
    • 100 $6.72
    • 1000 $6.33
    • 10000 $6.33
    Buy Now
    Bristol Electronics SN74ALS688DW 1,958
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    Quest Components SN74ALS688DW 1,520
    • 1 $7.128
    • 10 $7.128
    • 100 $7.128
    • 1000 $3.564
    • 10000 $3.564
    Buy Now
    SN74ALS688DW 298
    • 1 $8.9775
    • 10 $8.9775
    • 100 $3.8903
    • 1000 $3.591
    • 10000 $3.591
    Buy Now
    SN74ALS688DW 45
    • 1 $8.9775
    • 10 $8.9775
    • 100 $5.5361
    • 1000 $5.5361
    • 10000 $5.5361
    Buy Now
    SN74ALS688DW 29
    • 1 $8.9775
    • 10 $6.5835
    • 100 $5.985
    • 1000 $5.985
    • 10000 $5.985
    Buy Now
    SN74ALS688DW 4
    • 1 $8.9775
    • 10 $6.5835
    • 100 $6.5835
    • 1000 $6.5835
    • 10000 $6.5835
    Buy Now
    Rochester Electronics SN74ALS688DW 2,251 1
    • 1 $4.69
    • 10 $4.69
    • 100 $4.41
    • 1000 $3.99
    • 10000 $3.99
    Buy Now
    Ameya Holding Limited SN74ALS688DW 9,680
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote

    Rochester Electronics LLC SN74ALS688DW

    SN74ALS688 8-BIT IDENTITY/MAGNIT
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74ALS688DW Bulk 65
    • 1 -
    • 10 -
    • 100 $4.65
    • 1000 $4.65
    • 10000 $4.65
    Buy Now

    Texas Instruments SN74ALS688DWR

    IC COMPARATOR IDENTITY 8B 20SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74ALS688DWR Cut Tape 1
    • 1 $6.39
    • 10 $6.39
    • 100 $6.39
    • 1000 $6.39
    • 10000 $6.39
    Buy Now
    SN74ALS688DWR Reel 2,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $3.32106
    Buy Now
    Mouser Electronics SN74ALS688DWR
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $3.19
    Get Quote
    Bristol Electronics SN74ALS688DWR 1,958
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    Quest Components SN74ALS688DWR 3,722
    • 1 $6.66
    • 10 $6.66
    • 100 $6.66
    • 1000 $2.442
    • 10000 $2.331
    Buy Now
    SN74ALS688DWR 540
    • 1 $6.66
    • 10 $6.66
    • 100 $4.107
    • 1000 $3.663
    • 10000 $3.663
    Buy Now
    Rochester Electronics SN74ALS688DWR 5,693 1
    • 1 $3.48
    • 10 $3.48
    • 100 $3.27
    • 1000 $2.96
    • 10000 $2.96
    Buy Now
    Chip 1 Exchange SN74ALS688DWR 4,799
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote

    Texas Instruments SN74ALS688DWG4

    IC COMPARATOR IDENTITY 8B 20SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74ALS688DWG4 Tube 100
    • 1 -
    • 10 -
    • 100 $5.7853
    • 1000 $5.7853
    • 10000 $5.7853
    Buy Now

    SN74ALS688DW Datasheets (19)

    Part ECAD Model Manufacturer Description Curated Type PDF
    SN74ALS688DW Texas Instruments 8 Bit Identity Comparator Original PDF
    SN74ALS688DW Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DW Texas Instruments SN74ALS688 - 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DW Unknown Historical semiconductor price guide (US$ - 1998). From our catalog scanning project. Historical PDF
    SN74ALS688DW Texas Instruments 8-BIT IDENTITY COMPARATORS Scan PDF
    SN74ALS688DWE4 Texas Instruments 8-Bit IDENTITY COMPARATOR Original PDF
    SN74ALS688DWE4 Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWE4 Texas Instruments SN74ALS688 - 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWG4 Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWG4 Texas Instruments SN74ALS688 - 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWR Texas Instruments 8-Bit Comparator with Output-Enable Original PDF
    SN74ALS688DWR Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWR Texas Instruments 8-BIT IDENTITY COMPARATORS Original PDF
    SN74ALS688DWR Texas Instruments SN74ALS688 - 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWRE4 Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWRE4 Texas Instruments 8-Bit IDENTITY COMPARATOR Original PDF
    SN74ALS688DWRE4 Texas Instruments SN74ALS688 - 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWRG4 Texas Instruments 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF
    SN74ALS688DWRG4 Texas Instruments SN74ALS688 - 8-Bit Identity/Magnitude Comparators (P=Q) with Enable 20-SOIC 0 to 70 Original PDF

    SN74ALS688DW Datasheets Context Search

    Catalog Datasheet MFG & Type PDF Document Tags

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688

    Arduino Mega2560

    Abstract: 13001 S 6D TRANSISTOR arduino uno rev 3 agilent optical encoder 9988 MZ 13001 TRANSISTOR arduino mega 2650 skiip 613 gb 123 ct arduino sound sensor module pic arduino nano mc34063l
    Text: ND3% BASE1 XXXX2108-0010-1-P 10 TSQ: 3001 CMS: CMS-USM TS host OP: NN COMP: 15-07-11 Hour: 13:07 TS:TS date TS time MCUS, MPUS, DSPS & DEVELOPMENT TOOLS Find Datasheets Online 8-BIT MCUS & DEVELOPMENT TOOLS 1 PSoC 3 DEVELOPMENT KITS ARDUINO MCU DEVLOPMENT PLATFORM


    Original
    PDF CY8C38 CY8C29 incl795 12T9797 12T9804 12T9803 12T9800 12T9802 12T9801 12T9805 Arduino Mega2560 13001 S 6D TRANSISTOR arduino uno rev 3 agilent optical encoder 9988 MZ 13001 TRANSISTOR arduino mega 2650 skiip 613 gb 123 ct arduino sound sensor module pic arduino nano mc34063l

    5962-88578012A

    Abstract: 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688 5962-88578012A 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688

    SN74ALS688NSR

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688 SN74ALS688NSR

    5962-88578012A

    Abstract: 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688 5962-88578012A 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688

    5962-88578012A

    Abstract: 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688 5962-88578012A 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688

    SN74ALS688NSR

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688 SN74ALS688NSR

    5962-88578012A

    Abstract: 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688 SN74ALS688NSR
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688 5962-88578012A 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688 SN74ALS688NSR

    ALS688

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688

    SN74ALS688NSR

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688 SN74ALS688NSR

    SN74ALS688NSR

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688 SN74ALS688NSR

    5962-88578012A

    Abstract: 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688 SN74ALS688NSR
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688 5962-88578012A 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688 SN74ALS688NSR

    SN74ALS688NSR

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688 SN74ALS688NSR

    c5088 transistor

    Abstract: transistor C3207 TLO84CN sec c5088 IN5355B D2817A C3207 transistor toshiba f630 TLO81CP MC74HC533N
    Text: Transistor - Diode Cross Reference - H.P. Part Numbers to JEDEC Numbers Part Num. 1820-0225 1820-0240 1820-0352 1820-1804 1821-0001 1821-0002 1821-0006 1850-0062 1850-0064 1850-0075 1850-0076 1850-0093 1850-0099 1850-0126 1850-0137 1850-0150 1850-0151 1850-0154


    Original
    PDF 1853IMPATT c5088 transistor transistor C3207 TLO84CN sec c5088 IN5355B D2817A C3207 transistor toshiba f630 TLO81CP MC74HC533N

    SN74ALS688NSR

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A ALS688 ALS521 300-mil SN54ALS688 SN74ALS688 SN54ALS688 SN74ALS688NSR

    5962-88578012A

    Abstract: 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688 SN74ALS688NSR
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688 5962-88578012A 5962-8857801RA 5962-8857801SA SN54ALS688 SN74ALS688 SN74ALS688NSR

    Untitled

    Abstract: No abstract text available
    Text: SN54ALS688, SN74ALS688 8-BIT IDENTITY COMPARATORS SDAS228A – JUNE 1982 – REVISED JANUARY 1995 SN54ALS688 . . . J PACKAGE SN74ALS688 . . . DW OR N PACKAGE TOP VIEW G P0 Q0 P1 Q1 P2 Q2 P3 Q3 GND description These identity comparators perform comparisons


    Original
    PDF SN54ALS688, SN74ALS688 SDAS228A SN54ALS688

    SN74LS00N

    Abstract: SN74LS14N SN74HC74D SN74HC125D SN74LS04N SN74HC138D SN74LS163AN SN74LS138N SN74LS126AN sn74ls148n
    Text: Semiconductor Directory Mfr.Õs Type 13 Price Mfr.Õs Code Page Mfr.Õs Type Price Mfr.Õs Code Page Mfr.Õs Type Price Mfr.Õs Code Page Mfr.Õs Type Price Mfr.Õs Code Page SN74ALS109AN SN74ALS10AN SN74ALS112AN SN74ALS11AN SN74ALS139N 0.64 0.37 0.76 0.53


    Original
    PDF SN74ALS109AN SN74AS804BN SN74HC165N SN74LS07N SN74ALS10AN SN74AS805BN SN74HC166N SN74LS08D SN74ALS112AN SN74AS808BN SN74LS00N SN74LS14N SN74HC74D SN74HC125D SN74LS04N SN74HC138D SN74LS163AN SN74LS138N SN74LS126AN sn74ls148n