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

    SN74HC74 Search Results

    SN74HC74 Result Highlights (5)

    Part ECAD Model Manufacturer Description Download Buy
    SN74HC74DRG4
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SOIC -40 to 85 Visit Texas Instruments Buy
    SN74HC74MPWREP
    Texas Instruments Enhanced Product Dual D-Type Positive Edge Triggered Flip Flop With Clear And Preset 14-TSSOP -55 to 125 Visit Texas Instruments Buy
    SN74HC74APWR
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset Visit Texas Instruments Buy
    SN74HC74NSR
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SO -40 to 85 Visit Texas Instruments Buy
    SN74HC74DR
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SOIC -40 to 85 Visit Texas Instruments Buy
    SF Impression Pixel

    SN74HC74 Price and Stock

    Texas Instruments SN74HC74PW

    IC FF D-TYPE DBL 1-BIT 14-TSSOP
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74HC74PW Tube 27,349 1
    • 1 $0.99
    • 10 $0.71
    • 100 $0.56911
    • 1000 $0.5037
    • 10000 $0.45713
    Buy Now
    Bristol Electronics () SN74HC74PW 630
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    SN74HC74PW 10
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote

    Texas Instruments SN74HC74PWR

    IC FF D-TYPE DBL 1-BIT 14-TSSOP
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74HC74PWR Cut Tape 15,801 1
    • 1 $0.21
    • 10 $0.145
    • 100 $0.1089
    • 1000 $0.09017
    • 10000 $0.09017
    Buy Now
    Mouser Electronics SN74HC74PWR 22,921
    • 1 $0.48
    • 10 $0.288
    • 100 $0.184
    • 1000 $0.118
    • 10000 $0.083
    Buy Now
    Bristol Electronics () SN74HC74PWR 1,698
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    SN74HC74PWR 257
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote

    Texas Instruments SN74HC74QDRG4Q1

    IC FF D-TYPE DOUBLE 1BIT 14SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey () SN74HC74QDRG4Q1 Cut Tape 5,398 1
    • 1 $0.56
    • 10 $0.395
    • 100 $0.3083
    • 1000 $0.26622
    • 10000 $0.26622
    Buy Now
    SN74HC74QDRG4Q1 Digi-Reel 5,398 1
    • 1 $0.56
    • 10 $0.395
    • 100 $0.3083
    • 1000 $0.26622
    • 10000 $0.26622
    Buy Now
    SN74HC74QDRG4Q1 Reel 5,000 2,500
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $0.24081
    Buy Now
    Mouser Electronics SN74HC74QDRG4Q1 2,052
    • 1 $0.56
    • 10 $0.395
    • 100 $0.309
    • 1000 $0.26
    • 10000 $0.212
    Buy Now
    Rochester Electronics SN74HC74QDRG4Q1 215 1
    • 1 -
    • 10 -
    • 100 $0.2371
    • 1000 $0.1968
    • 10000 $0.1755
    Buy Now

    Texas Instruments SN74HC74NSR

    IC FF D-TYPE DOUBLE 1-BIT 14-SO
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey () SN74HC74NSR Digi-Reel 2,993 1
    • 1 $0.79
    • 10 $0.564
    • 100 $0.4446
    • 1000 $0.39321
    • 10000 $0.39321
    Buy Now
    SN74HC74NSR Cut Tape 2,993 1
    • 1 $0.79
    • 10 $0.564
    • 100 $0.4446
    • 1000 $0.39321
    • 10000 $0.39321
    Buy Now
    SN74HC74NSR Reel 2,000 2,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $0.34946
    Buy Now
    Mouser Electronics SN74HC74NSR 2,119
    • 1 $0.71
    • 10 $0.519
    • 100 $0.424
    • 1000 $0.37
    • 10000 $0.339
    Buy Now
    Arrow Electronics SN74HC74NSR Cut Strips 809 6 Weeks 1
    • 1 $0.3609
    • 10 $0.3552
    • 100 $0.3439
    • 1000 $0.3326
    • 10000 $0.3326
    Buy Now
    Bristol Electronics SN74HC74NSR 3,013 7
    • 1 -
    • 10 $0.7313
    • 100 $0.4753
    • 1000 $0.2048
    • 10000 $0.1901
    Buy Now
    Rochester Electronics SN74HC74NSR 806 1
    • 1 -
    • 10 -
    • 100 $0.4352
    • 1000 $0.3612
    • 10000 $0.322
    Buy Now

    Texas Instruments SN74HC74PWT

    IC FF D-TYPE DBL 1-BIT 14-TSSOP
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey () SN74HC74PWT Cut Tape 2,458 1
    • 1 $0.99
    • 10 $0.71
    • 100 $0.5643
    • 1000 $0.5643
    • 10000 $0.5643
    Buy Now
    SN74HC74PWT Digi-Reel 2,458 1
    • 1 $0.99
    • 10 $0.71
    • 100 $0.5643
    • 1000 $0.5643
    • 10000 $0.5643
    Buy Now
    SN74HC74PWT Reel 2,250 250
    • 1 -
    • 10 -
    • 100 -
    • 1000 $0.49489
    • 10000 $0.47559
    Buy Now
    Rochester Electronics SN74HC74PWT 64 1
    • 1 -
    • 10 -
    • 100 $0.5606
    • 1000 $0.4653
    • 10000 $0.4148
    Buy Now

    SN74HC74 Datasheets (130)

    Part ECAD Model Manufacturer Description Curated Datasheet Type PDF PDF Size Page count
    SN74HC74
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Original PDF 134.57KB 6
    SN74HC74
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset Original PDF 96.63KB 6
    SN74HC74ADBLE
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Original PDF 96.62KB 6
    SN74HC74ADBLE
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SSOP -40 to 85 Original PDF 731.58KB 20
    SN74HC74ADBLE
    Texas Instruments SN74HC74 - Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SSOP -40 to 85 Original PDF 1.2MB 22
    SN74HC74ADBR
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Original PDF 96.62KB 6
    SN74HC74ADBR
    Texas Instruments SN74HC74 - IC HC/UH SERIES, DUAL POSITIVE EDGE TRIGGERED D FLIP-FLOP, COMPLEMENTARY OUTPUT, PDSO14, SSOP-14, FF/Latch Original PDF 1.2MB 22
    SN74HC74ADBRE4
    Texas Instruments SN74HC74 - IC HC/UH SERIES, DUAL POSITIVE EDGE TRIGGERED D FLIP-FLOP, COMPLEMENTARY OUTPUT, PDSO14, SSOP-14, FF/Latch Original PDF 1.2MB 22
    SN74HC74D
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SOIC -40 to 85 Original PDF 731.58KB 20
    SN74HC74D
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops with Clear and Preset Original PDF 352.16KB 14
    SN74HC74D
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Original PDF 96.62KB 6
    SN74HC74D
    Texas Instruments SN74HC74 - Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SOIC -40 to 85 Original PDF 1.2MB 22
    SN74HC74D
    Unknown Historical semiconductor price guide (US$ - 1998). From our catalog scanning project. Historical PDF 40.04KB 1
    SN74HC74D
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Scan PDF 95.5KB 3
    SN74HC74D-00
    Texas Instruments SN74HC74 - IC HC/UH SERIES, DUAL POSITIVE EDGE TRIGGERED D FLIP-FLOP, COMPLEMENTARY OUTPUT, PDSO14, FF/Latch Original PDF 1.2MB 22
    SN74HC74DB
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET Original PDF 96.63KB 6
    SN74HC74DBLE
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Original PDF 96.62KB 6
    SN74HC74DBLE
    Texas Instruments Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SSOP -40 to 85 Original PDF 731.58KB 20
    SN74HC74DBLE
    Texas Instruments SN74HC74 - Dual D-Type Positive-Edge-Triggered Flip-Flops With Clear and Preset 14-SSOP -40 to 85 Original PDF 1.2MB 22
    SN74HC74DBR
    Texas Instruments DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET Original PDF 96.62KB 6
    ...

    SN74HC74 Datasheets Context Search

    Catalog Datasheet Type Document Tags PDF

    SN74HC74

    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET _ SCLS094A - DECEMBER 1982 - REVISED JANUARY 1996 Package Options Include Plastic Small-Outline D , Shrink Small-Outline (DB), Thin Shrink Small-Outline (PW), and


    OCR Scan
    SN54HC74, SN74HC74 SCLS094A 300-mil SN54HC74. SN74HC74 PDF

    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 PDF

    HC74

    Abstract: SN74HC74 SN54HC74 SN74HC74D SN74HC74DBR SN74HC74DR SN74HC74N SN74HC74NSR SN74HC74PW
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094C – DECEMBER 1982 – REVISED DECEMBER 2002 D D D D D D SN54HC74 . . . J OR W PACKAGE SN74HC74 . . . D, DB, N, NS, OR PW PACKAGE TOP VIEW Wide Operating Voltage Range of 2 V to 6 V


    Original
    SN54HC74, SN74HC74 SCLS094C SN54HC74 HC74 SN74HC74 SN54HC74 SN74HC74D SN74HC74DBR SN74HC74DR SN74HC74N SN74HC74NSR SN74HC74PW PDF

    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 PDF

    SN74HC74

    Abstract: HC74 MPDI002A MS-001 SN54HC74
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094B – DECEMBER 1982 – REVISED MAY 1997 D SN54HC74 . . . J OR W PACKAGE SN74HC74 . . . D, DB, N, OR PW PACKAGE TOP VIEW Package Options Include Plastic Small-Outline (D), Shrink Small-Outline


    Original
    SN54HC74, SN74HC74 SCLS094B SN54HC74 300-mil 4040049/C MS-001 20-pin MS-001) SN74HC74 HC74 MPDI002A MS-001 SN54HC74 PDF

    Contextual Info: SN74HC74-EP DUAL D-TYPE POSITIVE EDGE TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET www.ti.com SCLS710 – MARCH 2008 FEATURES 1 • • • • • 1 • • • • • • Controlled Baseline – One Assembly Site – One Test Site – One Fabrication Site


    Original
    SN74HC74-EP SCLS710 PDF

    SN74HC74DR

    Abstract: SN74HC74DT
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 SN74HC74DR SN74HC74DT PDF

    SN74HC74D

    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 SN74HC74D PDF

    HC74

    Abstract: SN54HC74 SN74HC74 SN74HC74D SN74HC74DBR SN74HC74DR SN74HC74DT SN74HC74N SN74HC74NSR
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 HC74 SN54HC74 SN74HC74 SN74HC74D SN74HC74DBR SN74HC74DR SN74HC74DT SN74HC74N SN74HC74NSR PDF

    Contextual Info: SN74HC74-EP DUAL D-TYPE POSITIVE EDGE TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET www.ti.com SCLS710 – MARCH 2008 FEATURES 1 • • • • • 1 • • • • • • Controlled Baseline – One Assembly Site – One Test Site – One Fabrication Site


    Original
    SN74HC74-EP SCLS710 PDF

    Contextual Info: SN74HC74ĆQ1 DUAL DĆTYPE POSITIVEĆEDGEĆTRIGGERED FLIPĆFLOP WITH CLEAR AND PRESET SCLS577A − MARCH 2004 − REVISED APRIL 2008 D D D D D D D Qualified for Automotive Applications Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads


    Original
    SN74HC74Q1 SCLS577A SN74HC74 PDF

    Contextual Info: SN74HC74ĆQ1 DUAL DĆTYPE POSITIVEĆEDGEĆTRIGGERED FLIPĆFLOP WITH CLEAR AND PRESET SCLS577 − MARCH 2004 D Qualification in Accordance With D D D D D D D D D OR PW PACKAGE TOP VIEW AEC-Q100† Qualified for Automotive Applications Customer-Specific Configuration Control


    Original
    SN74HC74Q1 SCLS577 AEC-Q100 SN74HC74 PDF

    Contextual Info: SN74HC74ĆQ1 DUAL DĆTYPE POSITIVEĆEDGEĆTRIGGERED FLIPĆFLOP WITH CLEAR AND PRESET SCLS577A − MARCH 2004 − REVISED APRIL 2008 D D D D D D D Qualified for Automotive Applications Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads


    Original
    SN74HC74Q1 SCLS577A SN74HC74 PDF

    Contextual Info: SN74HC74-Q1 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET SCLS577A − MARCH 2004 − REVISED APRIL 2008 D D D D D D D Qualified for Automotive Applications Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads


    Original
    SN74HC74-Q1 SCLS577A SN74HC74 PDF

    Contextual Info: SN74HC74-EP DUAL D-TYPE POSITIVE EDGE TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET www.ti.com SCLS710 – MARCH 2008 FEATURES 1 • • • • • 1 • • • • • • Controlled Baseline – One Assembly Site – One Test Site – One Fabrication Site


    Original
    SN74HC74-EP SCLS710 PDF

    Contextual Info: SN74HC74-Q1 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET SCLS577A − MARCH 2004 − REVISED APRIL 2008 D D D D D D D Qualified for Automotive Applications Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads


    Original
    SN74HC74-Q1 SCLS577A SN74HC74 PDF

    Contextual Info: w w w .t i.c om SN74HC74-EP DUAL D-TYPE POSITIVE EDGE TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET SCLS710 – MARCH 2008 FEATURES 1 • • • • • 1 Controlled Baseline – One Assembly Site – One Test Site – One Fabrication Site Extended Temperature Performance of –55°C


    Original
    SN74HC74-EP SCLS710 SN74HC74 PDF

    HC74

    Abstract: SN74HC74N
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 HC74 SN74HC74N PDF

    SN74HC74DR

    Abstract: HC74 SN54HC74 SN74HC74 SN74HC74D SN74HC74DBR SN74HC74DT SN74HC74N SN74HC74NSR
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74DR HC74 SN54HC74 SN74HC74 SN74HC74D SN74HC74DBR SN74HC74DT SN74HC74N SN74HC74NSR PDF

    SN74HC74

    Abstract: HC74 SN54HC74
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094A – DECEMBER 1982 – REVISED JANUARY 1996 D SN54HC74 . . . J OR W PACKAGE SN74HC74 . . . D, DB, N, OR PW PACKAGE TOP VIEW Package Options Include Plastic Small-Outline (D), Shrink Small-Outline


    Original
    SN54HC74, SN74HC74 SCLS094A SN54HC74 300-mil SN74HC74 HC74 SN54HC74 PDF

    HC74

    Abstract: SNV54HC74W SN74HC74DT
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 HC74 SNV54HC74W SN74HC74DT PDF

    Contextual Info: SN74HC74-EP DUAL D-TYPE POSITIVE EDGE TRIGGERED FLIP-FLOP WITH CLEAR AND PRESET www.ti.com SCLS710 – MARCH 2008 FEATURES 1 • • • • • 1 • • • • • • Controlled Baseline – One Assembly Site – One Test Site – One Fabrication Site


    Original
    SN74HC74-EP SCLS710 PDF

    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094D – DECEMBER 1982 – REVISED JULY 2003 D D D D D D Wide Operating Voltage Range of 2 V to 6 V Outputs Can Drive Up To 10 LSTTL Loads Low Power Consumption, 40-µA Max ICC


    Original
    SN54HC74, SN74HC74 SCLS094D SN54HC74 SN74HC74 PDF

    SN74HC74

    Abstract: HC74 SN54HC74
    Contextual Info: SN54HC74, SN74HC74 DUAL D-TYPE POSITIVE-EDGE-TRIGGERED FLIP-FLOPS WITH CLEAR AND PRESET SCLS094B – DECEMBER 1982 – REVISED MAY 1997 D SN54HC74 . . . J OR W PACKAGE SN74HC74 . . . D, DB, N, OR PW PACKAGE TOP VIEW Package Options Include Plastic Small-Outline (D), Shrink Small-Outline


    Original
    SN54HC74, SN74HC74 SCLS094B SN54HC74 300-mil SN74HC74 HC74 SN54HC74 PDF