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

    74LS15 Search Results

    74LS15 Result Highlights (5)

    Part ECAD Model Manufacturer Description Download Buy
    74LS153FPEL-E Renesas Electronics Corporation HD74LS Series Visit Renesas Electronics Corporation
    74LS153P-E Renesas Electronics Corporation HD74LS Series Visit Renesas Electronics Corporation
    74LS156P-E Renesas Electronics Corporation HD74LS Series Visit Renesas Electronics Corporation
    74LS151P-E Renesas Electronics Corporation HD74LS Series Visit Renesas Electronics Corporation
    74LS155P-E Renesas Electronics Corporation HD74LS Series Visit Renesas Electronics Corporation
    SF Impression Pixel

    74LS15 Price and Stock

    Texas Instruments SN74LS157DR

    IC MULTIPLEXER 4 X 2:1 16SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74LS157DR Cut Tape 4,620 1
    • 1 $0.64
    • 10 $0.453
    • 100 $0.3546
    • 1000 $0.30308
    • 10000 $0.30308
    Buy Now
    SN74LS157DR Digi-Reel 4,620 1
    • 1 $0.64
    • 10 $0.453
    • 100 $0.3546
    • 1000 $0.30308
    • 10000 $0.30308
    Buy Now
    SN74LS157DR Reel 2,500 2,500
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $0.29021
    Buy Now
    Mouser Electronics SN74LS157DR 3,684
    • 1 $0.46
    • 10 $0.286
    • 100 $0.254
    • 1000 $0.253
    • 10000 $0.252
    Buy Now
    Rochester Electronics SN74LS157DR 135,000 1
    • 1 $0.2806
    • 10 $0.2806
    • 100 $0.2638
    • 1000 $0.2385
    • 10000 $0.2385
    Buy Now
    ComSIT USA SN74LS157DR 1,568
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote

    Texas Instruments SN74LS153DR

    IC MULTIPLEXER 2 X 4:1 16SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74LS153DR Digi-Reel 3,766 1
    • 1 $0.8
    • 10 $0.57
    • 100 $0.4495
    • 1000 $0.38648
    • 10000 $0.38648
    Buy Now
    SN74LS153DR Cut Tape 3,766 1
    • 1 $0.8
    • 10 $0.57
    • 100 $0.4495
    • 1000 $0.38648
    • 10000 $0.38648
    Buy Now
    Mouser Electronics SN74LS153DR 2,133
    • 1 $0.8
    • 10 $0.512
    • 100 $0.419
    • 1000 $0.386
    • 10000 $0.335
    Buy Now

    Texas Instruments SN74LS156NSR

    IC DECODER/DEMUX 2 X 1:4 16SO
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74LS156NSR Digi-Reel 3,114 1
    • 1 $0.97
    • 10 $0.698
    • 100 $0.5546
    • 1000 $0.47928
    • 10000 $0.47928
    Buy Now
    SN74LS156NSR Reel 2,000 2,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $0.38804
    Buy Now
    SN74LS156NSR Cut Tape 1,114 1
    • 1 $0.97
    • 10 $0.698
    • 100 $0.5546
    • 1000 $0.47928
    • 10000 $0.47928
    Buy Now
    Mouser Electronics SN74LS156NSR 3,424
    • 1 $0.97
    • 10 $0.63
    • 100 $0.519
    • 1000 $0.479
    • 10000 $0.391
    Buy Now

    Texas Instruments SN74LS156DR

    IC DECODER/DEMUX 2X1:4 16SOIC
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74LS156DR Digi-Reel 2,878 1
    • 1 $0.8
    • 10 $0.57
    • 100 $0.4495
    • 1000 $0.38648
    • 10000 $0.38648
    Buy Now
    SN74LS156DR Cut Tape 2,878 1
    • 1 $0.8
    • 10 $0.57
    • 100 $0.4495
    • 1000 $0.38648
    • 10000 $0.38648
    Buy Now
    Bristol Electronics SN74LS156DR 1,437
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    Rochester Electronics SN74LS156DR 62,501 1
    • 1 $0.3611
    • 10 $0.3611
    • 100 $0.3394
    • 1000 $0.3069
    • 10000 $0.3069
    Buy Now

    Texas Instruments SN74LS158NSR

    IC MULTIPLEXER 4 X 2:1 16SO
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey SN74LS158NSR Digi-Reel 2,000 1
    • 1 $0.48
    • 10 $0.333
    • 100 $0.2582
    • 1000 $0.21891
    • 10000 $0.21891
    Buy Now
    SN74LS158NSR Reel 2,000 2,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 $0.19831
    Buy Now
    SN74LS158NSR Cut Tape 2,000 1
    • 1 $0.48
    • 10 $0.333
    • 100 $0.2582
    • 1000 $0.21891
    • 10000 $0.21891
    Buy Now

    74LS15 Datasheets (91)

    Part ECAD Model Manufacturer Description Curated Datasheet Type PDF
    74LS15 Motorola Triple 3-Input AND Gate Original PDF
    74LS15 Fairchild Semiconductor Full Line Condensed Catalogue 1977 Scan PDF
    74LS15 Raytheon Positive-AND Gates With Open-Collector Outputs Scan PDF
    74LS15 Signetics Integrated Circuits Catalogue 1978/79 Scan PDF
    74LS151 Fairchild Semiconductor 1-of-8 Line Data Selector/Multiplexer Original PDF
    74LS151 Hitachi Semiconductor 1-of-8 Data Selectors/Multiplexers(with strobe) Original PDF
    74LS151 Motorola 8-INPUT MULTIPLEXER Original PDF
    74LS151 On Semiconductor LOW POWER SCHOTTKY Original PDF
    74LS151 Texas Instruments DATA SELECTORS/MULTIPLEXERS Original PDF
    74LS151 Fairchild Semiconductor Full Line Condensed Catalogue 1977 Scan PDF
    74LS151 Signetics 8-Input Multiplexer Scan PDF
    74LS151 Signetics 8-Input Multiplexer Scan PDF
    74LS151 Signetics Integrated Circuits Catalogue 1978/79 Scan PDF
    74LS151C Unknown TTL Data Book 1980 Scan PDF
    74LS151DC Fairchild Semiconductor 8-Input Multiplexer Scan PDF
    74LS151FC Fairchild Semiconductor 8-Input Multiplexer Scan PDF
    74LS151M Unknown TTL Data Book 1980 Scan PDF
    74LS151PC Fairchild Semiconductor 8-Input Multiplexer Scan PDF
    74LS152 Fairchild Semiconductor Full Line Condensed Catalogue 1977 Scan PDF
    74LS152FC Fairchild Semiconductor 8-Input Multiplexer Scan PDF

    74LS15 Datasheets Context Search

    Catalog Datasheet MFG & Type Document Tags PDF

    motorola zc 5276

    Abstract: 74LS158 circuit diagram of 32-1 multiplexer LS158 SN54LSXXXJ SN74LSXXXD SN74LSXXXN
    Text: SN54/74LS158 QUAD 2-INPUT MULTIPLEXER The LSTTL/ MSI SN54L/ 74LS158 is a high speed Quad 2-input Multiplexer. It selects four bits of data from two sources using the common Select and Enable inputs. The four buffered outputs present the selected data in the


    Original
    SN54/74LS158 SN54L/ 74LS158 LS158 motorola zc 5276 circuit diagram of 32-1 multiplexer SN54LSXXXJ SN74LSXXXD SN74LSXXXN PDF

    FAST AND LS TTL

    Abstract: 751A-02 b8pl
    Text: SN54/74LS15 TRIPLE 3-INPUT AND GATE TRIPLE 3-INPUT AND GATE VCC 14 LOW POWER SCHOTTKY 13 12 11 10 9 * 8 * * 1 2 3 4 5 6 J SUFFIX CERAMIC CASE 632-08 7 14 GND * OPEN 1 COLLECTOR OUTPUTS N SUFFIX PLASTIC CASE 646-06 14 1 14 1 D SUFFIX SOIC CASE 751A-02 ORDERING INFORMATION


    Original
    SN54/74LS15 51A-02 SN54LSXXJ SN74LSXXN SN74LSXXD FAST AND LS TTL 751A-02 b8pl PDF

    74LS15

    Abstract: 751A-02
    Text: SN54/74LS15 TRIPLE 3-INPUT AND GATE TRIPLE 3-INPUT AND GATE VCC 14 LOW POWER SCHOTTKY 13 12 11 10 9 * 8 * * 1 2 3 4 5 6 J SUFFIX CERAMIC CASE 632-08 7 14 GND 1 * OPEN COLLECTOR OUTPUTS N SUFFIX PLASTIC CASE 646-06 14 1 14 1 D SUFFIX SOIC CASE 751A-02 ORDERING INFORMATION


    Original
    SN54/74LS15 51A-02 SN54LSXXJ SN74LSXXN SN74LSXXD 74LS15 751A-02 PDF

    74LS153

    Abstract: 74LS153 multiplexer truth table TTL 74ls153 74ls153 application notes MSI 74LS153 multiplexor 74LS153 LS153 SN54LSXXXJ SN74LSXXXD SN74LSXXXN
    Text: SN54/74LS153 DUAL 4-INPUT MULTIPLEXER The LSTTL / MSI SN54 / 74LS153 is a very high speed Dual 4-Input Multiplexer with common select inputs and individual enable inputs for each section. It can select two bits of data from four sources. The two buffered outputs present data in the true non-inverted form. In addition to multiplexer


    Original
    SN54/74LS153 74LS153 LS153 74LS153 multiplexer truth table TTL 74ls153 74ls153 application notes MSI 74LS153 multiplexor 74LS153 SN54LSXXXJ SN74LSXXXD SN74LSXXXN PDF

    IC 74LS153

    Abstract: 74153 mux cd 74153 ic 74153 IC - 74LS153 74LS153 8 to 1 mux 74LS153 74153 74s153 2C011
    Text: SN54153, SN 54LS153, SN 54S1S3 S N 74153, SN 74LS153, SN 74S153 DUAL 4 LINE TO 1-LINE DATA SELECTORSfM ULTIPLEXERS D E C E M B ER 1972 - R E V IS E D M A R C H 19B8 Permits Multiplexing from N lines to 1 line S N 54153, SN 5 4 LS1 5 3 , SN 5 4 S1 5 3 . . . J OR W


    OCR Scan
    SN54153, 54LS153, 54S1S3 74LS153, 74S153 IC 74LS153 74153 mux cd 74153 ic 74153 IC - 74LS153 74LS153 8 to 1 mux 74LS153 74153 2C011 PDF

    Diode RL 4B

    Abstract: DN74LS158 MA161
    Text: LS TTL DN74LS Series 74LS158 74LS158 Quad 2 -lin e to 1 -lin e Data S electors / Multiplexers • Description P -2 D N 74LS158 contains four 2-line to 1-line data selector/ m ultiplexer circuits. ■ Features • • • • • Inverted o u tp u t C om m on enable in p u t for all fo u r circuits


    OCR Scan
    DN74LS DN74LS158 DN74LS158 16-pin SO-16D) MA161. Diode RL 4B MA161 PDF

    LS251

    Abstract: 74LS151 multiplexers 74 LS 150 LS 74LS151 pin diagram 41 multiplexer 74ls151 74 LS 151 Logic DIAGRAM eight input multiplexer 54LS251 74LS1 74LS251
    Text: Am25LS151 • Am54LS/74LS151 Am25LS251Am54LS/74LS251 Eight-Input Multiplexers L O G IC D IA G R A M D IS T IN C T IV E C H A R A C T E R IS T IC S • • • • S w itches o n e -o f-e ig h t in p u ts to tw o co m p le m e n ta ry o u tp u ts S ta n d ard , 'L S 15 1 and three-state, 'L S 25 1 o u tp u t versions


    OCR Scan
    Am25LS151 Am54LS/74LS151 Am25LS251 Am54LS/74LS251 LS151 LS251 Am25LS Am54/74LS 440/jA MIL-STD-883 74LS151 multiplexers 74 LS 150 LS 74LS151 pin diagram 41 multiplexer 74ls151 74 LS 151 Logic DIAGRAM eight input multiplexer 54LS251 74LS1 74LS251 PDF

    Untitled

    Abstract: No abstract text available
    Text: GD54/74LS157 QUADRUPLE 2-T0-1-LINE DATA SELECTORS/MULTIPLEXERS NON INVERTED DATA OUTPUTS Feature • • Buffered Inputs and Outputs Common Strobe/Select input for all 4 circuits. Pin Configuration INPUTS Vcc S TRO BE 4 A 4B G 4B INPUTS O U TP U T -. O UTPUT


    OCR Scan
    GD54/74LS157 PDF

    74191 8 bit

    Abstract: 7443 Flip-Flop D134 7443 d Flip-Flop 74LS42 74155 9B23 D135 93L38 93L11
    Text: FAIRCHILD LOGIC/CONNECTION DIAGRAMS DIGITAL -TTL D130 54/74190, 74LS190 54/74191, 74LS191 D132 54/74155, 54LS/74LS155 54/74156, 54LS/74LS156 D131 9321, 93L21, 54/74S139, 54LS/74LS139 15 14 13 TTTT 12 11 10 9 Vcc = Pin 16 GND = Pin 8 Vcc = Pin 16 GND = Pin 8


    OCR Scan
    74LS190 74LS191 93L21, 54/74S139, 54LS/74LS139 54LS/74LS155 54LS/74LS156 93L01, 93L34, 54LS/74LS259 74191 8 bit 7443 Flip-Flop D134 7443 d Flip-Flop 74LS42 74155 9B23 D135 93L38 93L11 PDF

    74LS190 PIN diagram

    Abstract: ttl 7442 74LS42 74LS138 pin diagram D134 7442 pin diagram 74155 74145 D133 93L01
    Text: FAIRCHILD LOGIC/CONNECTION DIAGRAMS DIGITAL -TTL D130 54/74190, 74LS190 54/74191, 74LS191 D132 54/74155, 54LS/74LS155 54/74156, 54LS/74LS156 D131 9321, 93L21, 54/74S139, 54LS/74LS139 15 14 13 TTTT 12 11 10 9 Vcc = Pin 16 GND = Pin 8 Vcc = Pin 16 GND = Pin 8


    OCR Scan
    74LS190 74LS191 93L21, 54/74S139, 54LS/74LS139 54LS/74LS155 54LS/74LS156 93L01, 93L34, 54LS/74LS259 74LS190 PIN diagram ttl 7442 74LS42 74LS138 pin diagram D134 7442 pin diagram 74155 74145 D133 93L01 PDF

    7448 decoder

    Abstract: ID 9302 Fairchild 74190 pin diagram decoder 7447 TTL 7448 74LS47 74LS47 pin TTL 7446 decoder 74LS47 decoder 7448
    Text: FAIRCHILD LOGIC/CONNECTION DIAGRAMS DIGITAL -T T L D130 54/74190, 74LS190 54/74191, 74LS191 D132 54/74155, 54LS/74LS155 54/74156, 54LS/74LS156 D131 9321, 93L21, 54/74S139, 54LS/74LS139 15 14 13 TTTT 12 11 10 9 Vcc = Pin 16 G N D = Pin 8 Vcc = Pin 16 G N D = Pin 8


    OCR Scan
    74LS190 74LS191 93L21, 54/74S139, 54LS/74LS139 54LS/74LS155 54LS/74LS156 93L01, 93L34, 54LS/74LS259 7448 decoder ID 9302 Fairchild 74190 pin diagram decoder 7447 TTL 7448 74LS47 74LS47 pin TTL 7446 decoder 74LS47 decoder 7448 PDF

    transistor d133

    Abstract: Decoder BCD 7 seg ttl 7442 transistor 6B 7-seg ANODE COMMON 74155 74LS247 pin diagram of 74LS247 ttl 74191 75491
    Text: FAIRCHILD LOGIC/CONNECTION DIAGRAMS DIGITAL -T T L D130 54/74190, 74LS190 54/74191, 74LS191 D132 54/74155, 54LS/74LS155 54/74156, 54LS/74LS156 D131 9321, 93L21, 54/74S139, 54LS/74LS139 15 14 13 TTTT 12 11 10 9 Vcc = Pin 16 GND = Pin 8 Vcc = Pin 16 GND = Pin 8


    OCR Scan
    74LS190 74LS191 93L21, 54/74S139, 54LS/74LS139 54LS/74LS155 54LS/74LS156 93L01, 93L34, 54LS/74LS259 transistor d133 Decoder BCD 7 seg ttl 7442 transistor 6B 7-seg ANODE COMMON 74155 74LS247 pin diagram of 74LS247 ttl 74191 75491 PDF

    ALU IC 74181

    Abstract: 74181 ic pin diagram DS 7409 7480 full adder 1 bit 74LS86 full adder IC 74181 7411 3 INPUT AND gate TTL 74ls83 pin diagram of 7411 logic diagram of 7432
    Text: FAIRCHILD LOGIC/CONNECTION DIAGRAMS DIGITAL-TTL D16 547408, 54H/74H08, 54S/74S08, 54LS/74LS08 54/7409, 54S/74S09, 54LS/74LS09 D18 54/7411, 54H/74H11, 54S/74S11, 54LS/74LS11, 54S/74S15, 54LS/74LS15 D17 9S41 Vcc Vcc 1^1FH [iä| [vii Eòi [T| r»1 füi Fai np f i ! Föi lyi rn


    OCR Scan
    54H/74H08, 54S/74S08, 54LS/74LS08 54S/74S09, 54LS/74LS09 54H/74H21 54LS/74LS21 54S/74S32 54LS/74LS32 54H/74H11, ALU IC 74181 74181 ic pin diagram DS 7409 7480 full adder 1 bit 74LS86 full adder IC 74181 7411 3 INPUT AND gate TTL 74ls83 pin diagram of 7411 logic diagram of 7432 PDF

    74LS156FC

    Abstract: 54156DM 54LS156DM 74156DC 74156FC 74156PC 74LS156PC 74ls156
    Text: 15b T -6 6 -2 1 -5 3 _ C O N N E C T IO N D IA G R A M P IN O U T A 54/74156 54LS/74LS156 D U A L 1 - 0 F - 4 D E C O D E R / D E M U L T IP L E X E R With Open-Collector Outputs OUT A » [3 «3*0 6 *1 « Ô J/ V ) 23 Ö* 0.[é ïï] ô f c ou g go»


    OCR Scan
    54LS/74LS156 74156PC. 74LS156PC 74156DC. 74LS1560C 74156FC, 74LS156FC 54/74LS 54/74LS 74LS156FC 54156DM 54LS156DM 74156DC 74156FC 74156PC 74LS156PC 74ls156 PDF

    Untitled

    Abstract: No abstract text available
    Text: LS1S3 National Semiconductor 54L5153/DM 54L5153/DM 74LS153 Dual 4-Line to 1- Line Data Selectors/Multiplexers General Description Each of these data selectors/multiplexers contains invert­ ers and drivers to supply fully complementary, on-chip, bina­ ry decoding data selection to the AND-OR-invert gates.


    OCR Scan
    54L5153/DM 74LS153 54LS153) LS153 PDF

    TTL 74ls153

    Abstract: 74LS153 multiplexer truth table
    Text: MOTOROLA SN54/74LS153 DUAL 4-INPUT MULTIPLEXER The LSTTL/M SI SN 54/74LS 153 is a very high speed Dual 4-Input Multiplexer with common select inputs and individual enable inputs for each section. It can select two bits of data from four sources. The two buffered


    OCR Scan
    54/74LS LS153 SN54/74LS153 TTL 74ls153 74LS153 multiplexer truth table PDF

    74LS155

    Abstract: No abstract text available
    Text: MOTOROLA SN54LS/74LS155 SN54LS/74LS156 D E S C R IP T IO N — T h e S N 5 4 L S /7 4 L S 1 55 and S N 5 4 L S /7 4 L S 1 56 are high speed Dual 1-of-4 D ecoder/D em ultiplexers. These devices have tw o decoders w ith comm on 2-bit Address inputs and separate gated


    OCR Scan
    SN54LS/74LS155 SN54LS/74LS156 LS156 LS155 74LS155 PDF

    74S153

    Abstract: 74LS153
    Text: GD54/74LS153 DUAL 4-LINE TO 1-LINE DATA SELECTORS/MULTIPLEXERS Feature Pin Configuration • Permits Multiplexing from N lines to 1 line • Performs Parallel-to-Serial Conversion • Strobe Enable Line Provided for Cascading (N Lines to n Lines) • High-Fan-Out, Low-lmpedance, Totem-Pole


    OCR Scan
    GD54/74LS153 74S153 74LS153 PDF

    74151APC

    Abstract: of ic 74ls151 pin d 74151ADC 74LS151PC 74ls151 54151A TPL-34/12X46F
    Text: N AT IONAL SEMICOND -CLOGIO DEE D 1 0 1 I bSDiiBE OGbaaafi 4 I C O N N E C T IO N D IA G R A M PIN O U T A T-66-21-53 54/74151A 54S/74S151 54LS/74LS151 13[T 8 -IN P U T M U L T IP L E X E R Vcc I2 U D m Il [ I 7 3 Is io [ T 13] 16 z[s m I? zK 1 Î] So iE TÖ] S i


    OCR Scan
    54/74151A 54S/74S151 54LS/74LS151 T-66-21-53 54/74S 54/74LS 74151APC of ic 74ls151 pin d 74151ADC 74LS151PC 74ls151 54151A TPL-34/12X46F PDF

    Untitled

    Abstract: No abstract text available
    Text: SA NY O SEMICONDUCTOR CORP 12E D I ^ L C 7 4 H G 1 5 4 - i-l’7 z i - $ S CM OS High-Speed Standard Logic LC74H C Series 3084 - 4 : 7 eH7Q7Li DGDShiS fl í ~ to 1 6 - L in e D e co d e r C1740A Features ~ • The LC74HC154 is a 4-to-16 decoder. • Uses CMOS silicon gate process technology to. achieve operating speeds similar to L S 'T T L 74LS154 gates with the


    OCR Scan
    LC74H C1740A LC74HC154 4-to-16 74LS154) 54LS/74LS PDF

    Untitled

    Abstract: No abstract text available
    Text: GD54/74LS157 QUADRUPLE 2-T0-1-LINE DATA SELECTORS/MULTIPLEXERS NON INVERTED DATA OUTPUTS Feature Pin Configuration • • Buffered Inputs and Outputs Common Strobe/Select input for all 4 circuits. INPUTS Vcc STROBE 4A Descriptions j _ 16 j _ j j 5 j _ This monolitic data selector/multiplexer contains


    OCR Scan
    GD54/74LS157 PDF

    DN74LS153

    Abstract: MA161
    Text: I 74LS153 LS TTL DN74LS Series 74LS153 Dual 4-lin e to 1-line Data Selectors / Multiplexers • Description D N 74LS153 contains two 4-line to 1-line data selector/ m ultiplexer circuits. P-2 ■ Features • Independent enable input for each circuit • Common selection input for both circuits


    OCR Scan
    DN74LS DN74LS153 DN74LS153 16-pin SO-16D) trS15ns, MA161 PDF

    M74LS158P

    Abstract: ic 4001 pin configuration diagram 20-PIN
    Text: MITSUBISHI LSTTLs M 74LS158P QUADRUPLE 2-LINE TO 1-LINE DATA SELECTOR/MULTIPLEXER INVERTED DESCRIPTION The 74LS158P is a semiconductor integrated circuit containing four 2-line to 1-line data selector/multiplexer circuits. SELECTION INPUT FEATURES • •


    OCR Scan
    M74LS158P M74LS158P 16-PIN 20-PIN ic 4001 pin configuration diagram PDF

    DN74LS15

    Abstract: No abstract text available
    Text: I 74LS15 LS TTL DN74LS Series 74LS15 T rip le 3-input P o sitiv e AND G ates w ith Open C ollector Outputs P-1 • Description DN 74LS15 contains three 3-input positive isolation AND gate circuits w ith open collector o utputs. ■ Features • • •


    OCR Scan
    DN74LS DN74LS15 DN74LS15 14-pin SO-14D) PDF