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

    L4972 Search Results

    SF Impression Pixel

    L4972 Price and Stock

    Rochester Electronics LLC L4972AD

    IC REG BUCK ADJ 2A 20SO
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey L4972AD Bulk 881 77
    • 1 -
    • 10 -
    • 100 $3.94
    • 1000 $3.94
    • 10000 $3.94
    Buy Now

    STMicroelectronics L4972A

    IC REG BUCK ADJUSTABLE 2A 20DIP
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey L4972A Tube
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Buy Now
    Avnet Americas L4972A Tube 4 Weeks 128
    • 1 -
    • 10 -
    • 100 -
    • 1000 $2.7342
    • 10000 $2.6166
    Buy Now
    L4972A Tube 1,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    Newark L4972A Bulk 1
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Buy Now
    STMicroelectronics L4972A 850 1
    • 1 $6.25
    • 10 $5.63
    • 100 $4.61
    • 1000 $3.92
    • 10000 $3.92
    Buy Now
    Quest Components L4972A 13,200
    • 1 $5.4675
    • 10 $5.4675
    • 100 $5.4675
    • 1000 $2.0048
    • 10000 $1.9136
    Buy Now
    Rochester Electronics L4972A 9,800 1
    • 1 $2.86
    • 10 $2.86
    • 100 $2.69
    • 1000 $2.43
    • 10000 $2.43
    Buy Now

    STMicroelectronics L4972AD

    IC REG BUCK ADJ 2A 20SO
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey L4972AD Tube 1,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 $3.21204
    • 10000 $3.21204
    Buy Now
    Avnet Americas L4972AD Tube 4 Weeks 92
    • 1 -
    • 10 -
    • 100 $3.97215
    • 1000 $3.72645
    • 10000 $3.56265
    Buy Now
    L4972AD Tube 1,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    Verical L4972AD 480 40
    • 1 -
    • 10 -
    • 100 $5.2104
    • 1000 $5.2104
    • 10000 $5.2104
    Buy Now
    Newark L4972AD Bulk 1,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Buy Now
    STMicroelectronics L4972AD 1
    • 1 $6.25
    • 10 $5.63
    • 100 $4.61
    • 1000 $3.92
    • 10000 $3.92
    Buy Now
    Rochester Electronics L4972AD 881 1
    • 1 $3.98
    • 10 $3.98
    • 100 $3.74
    • 1000 $3.38
    • 10000 $3.38
    Buy Now
    TME L4972AD 1
    • 1 $5.83
    • 10 $5.25
    • 100 $4.65
    • 1000 $3.89
    • 10000 $3.89
    Get Quote

    Microchip Technology Inc CDLL4972

    VOLTAGE REGULATOR
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey CDLL4972 Bulk 100
    • 1 -
    • 10 -
    • 100 $9.65
    • 1000 $9.65
    • 10000 $9.65
    Buy Now
    Avnet Americas CDLL4972 Bulk 28 Weeks 100
    • 1 $10.4
    • 10 $10.4
    • 100 $9.65
    • 1000 $9.29
    • 10000 $9.29
    Buy Now
    Mouser Electronics CDLL4972
    • 1 -
    • 10 -
    • 100 $9.65
    • 1000 $9.65
    • 10000 $9.65
    Get Quote
    Newark CDLL4972 Bulk 100
    • 1 -
    • 10 -
    • 100 $9.65
    • 1000 $9.29
    • 10000 $9.29
    Buy Now
    Microchip Technology Inc CDLL4972
    • 1 $10.4
    • 10 $10.4
    • 100 $10.4
    • 1000 $10.4
    • 10000 $10.4
    Buy Now
    NAC CDLL4972 33
    • 1 $10.93
    • 10 $10.93
    • 100 $9.91
    • 1000 $9.06
    • 10000 $9.06
    Buy Now
    Master Electronics CDLL4972
    • 1 -
    • 10 -
    • 100 $10.19
    • 1000 $10.19
    • 10000 $10.19
    Buy Now

    STMicroelectronics L4972AD013TR

    IC REG BUCK ADJ 2A 20SO
    Distributors Part Package Stock Lead Time Min Order Qty Price Buy
    DigiKey L4972AD013TR Cut Tape 1
    • 1 $7.28
    • 10 $4.964
    • 100 $3.6921
    • 1000 $3.16754
    • 10000 $3.16754
    Buy Now
    L4972AD013TR Reel
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Buy Now
    Avnet Americas L4972AD013TR Reel 1,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote
    Newark L4972AD013TR Reel 1,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Buy Now
    STMicroelectronics L4972AD013TR 1
    • 1 $6.3
    • 10 $5.66
    • 100 $4.64
    • 1000 $3.95
    • 10000 $3.95
    Buy Now
    ComSIT USA L4972AD013TR 7,000
    • 1 -
    • 10 -
    • 100 -
    • 1000 -
    • 10000 -
    Get Quote

    L4972 Datasheets (23)

    Part ECAD Model Manufacturer Description Curated Type PDF
    L4972 STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972 STMicroelectronics 2A SWITCHINGREGULATOR Original PDF
    L4972 STMicroelectronics 2 Amp Switching Regulator Scan PDF
    L4972 STMicroelectronics 3.5A SWITCHING REGULATOR Scan PDF
    L4972A STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972A STMicroelectronics 2A SWITCHINGREGULATOR Original PDF
    L4972A STMicroelectronics 5A SWITCHING REGULATOR Original PDF
    L4972A STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972A STMicroelectronics HIGH CURRENT SWITCHING REGULATORS Original PDF
    L4972A STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972A STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972A Unknown Shortform IC and Component Datasheets (Plus Cross Reference Data) Short Form PDF
    L4972AD STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972AD STMicroelectronics 2A SWITCHINGREGULATOR Original PDF
    L4972AD STMicroelectronics 5A SWITCHING REGULATOR Original PDF
    L4972AD STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972AD STMicroelectronics HIGH CURRENT SWITCHING REGULATORS Original PDF
    L4972AD STMicroelectronics 2A SWITCHING REGULATOR Original PDF
    L4972AD Unknown Shortform IC and Component Datasheets (Plus Cross Reference Data) Short Form PDF
    L4972AD013TR STMicroelectronics 2A SWITCHING REGULATOR Original PDF

    L4972 Datasheets Context Search

    Catalog Datasheet MFG & Type PDF Document Tags

    58310

    Abstract: L4972D cogema L4970A thomson film capacitors L4972A L4972AD SO20 ERO Film Capacitor
    Text: L4972A L4972AD 2A SWITCHING REGULATOR . . . . . . . . 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE RESET AND POWER FAIL FUNCTIONS


    Original
    PDF L4972A L4972AD 200KHz L4972A 58310 L4972D cogema L4970A thomson film capacitors L4972AD SO20 ERO Film Capacitor

    core 58310 MAGNETICS

    Abstract: ero 1837 58310 EKR ROE ERO mkt Eyf ROE L4972D capacitor 100nf 63v MKT capacitor 470nF 63V MKT ERO kp 1830
    Text: L4972A L4972AD  2A SWITCHING REGULATOR . . . . . . . . 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE RESET AND POWER FAIL FUNCTIONS


    Original
    PDF L4972A L4972AD 200KHz L4972Aisa core 58310 MAGNETICS ero 1837 58310 EKR ROE ERO mkt Eyf ROE L4972D capacitor 100nf 63v MKT capacitor 470nF 63V MKT ERO kp 1830

    kp 63v capacitor

    Abstract: L4970A L4972 capacitor 470nF 63V MKT ERO Film Capacitor ERO mkt DIP20 L4972A L4972AD L4972AD013TR
    Text: L4972A 2A SWITCHING REGULATOR 1 • ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 2 Features 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE


    Original
    PDF L4972A 200KHz L4972A PowerDIP20 kp 63v capacitor L4970A L4972 capacitor 470nF 63V MKT ERO Film Capacitor ERO mkt DIP20 L4972AD L4972AD013TR

    L4970A

    Abstract: L4972A L4972AD SO20 core 58310 MAGNETICS
    Text: L4972A L4972AD 2A SWITCHING REGULATOR . . . . . . . . 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE RESET AND POWER FAIL FUNCTIONS


    Original
    PDF L4972A L4972AD 200KHz L4972A L4970A L4972AD SO20 core 58310 MAGNETICS

    L4974A

    Abstract: L4972A
    Text: L4972A 2A / L4974A (3.5A) Switching Regulator - Datasheet 71mm 66mm Serigraphy Component Layer Back Layer


    Original
    PDF L4972A L4974A L4974A L4972A

    Untitled

    Abstract: No abstract text available
    Text: L4972A 2A SWITCHING REGULATOR 1 • ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 2 Features 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE


    Original
    PDF L4972A 200KHz L4972A PowerDIP20

    L4970A

    Abstract: L4972A L4972AD SO20 cogema 4.7k Preset
    Text: L4972A L4972AD 2A SWITCHING REGULATOR . . . . . . . . 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE RESET AND POWER FAIL FUNCTIONS


    Original
    PDF L4972A L4972AD 200KHz L4972A L4970A L4972AD SO20 cogema 4.7k Preset

    ERO kp 1830

    Abstract: L4972A L4970A L4972AD SO20 core 58310 MAGNETICS ero 1830
    Text: L4972A L4972AD 2A SWITCHING REGULATOR . . . . . . . . 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE RESET AND POWER FAIL FUNCTIONS


    Original
    PDF L4972A L4972AD 200KHz L4972A ERO kp 1830 L4970A L4972AD SO20 core 58310 MAGNETICS ero 1830

    lme49

    Abstract: No abstract text available
    Text: LME49725 LME49725 PowerWise Dual High Performance, High Fidelity Audio Operational Amplifier Literature Number: SNAS427 LME49725 PowerWise® Dual High Performance, High Fidelity Audio Operational Amplifier General Description Key Specifications The LME49725 is part of the ultra-low distortion, low noise,


    Original
    PDF LME49725 LME49725 SNAS427 LME49725/clocks lme49

    400w power amplifier circuit diagram

    Abstract: L497X amplifier 400W L4970A SCHEMATIC DIAGRAM POWER SUPPLY 12v 10A power supply 12v 10a out put circuit diagram L4970 voltage regulator PWM 1995 transconductance voltage regulator PWM 1995 transconductance sink 16 to 12v 400W CIRCUIT DIAGRAM
    Text: APPLICATION NOTE INTRODUCTION TO A 10A MONOLITHIC SWITCHING REGULATOR IN MULTIPOWER-BCD TECHNOLOGY by C.Diazzi The L497X series of high current switching regulator ICs exploit Multipower-BCD technology to achieve very high output currents with low power dissipation – up to 10A in the Multiwatt power


    Original
    PDF L497X 400w power amplifier circuit diagram amplifier 400W L4970A SCHEMATIC DIAGRAM POWER SUPPLY 12v 10A power supply 12v 10a out put circuit diagram L4970 voltage regulator PWM 1995 transconductance voltage regulator PWM 1995 transconductance sink 16 to 12v 400W CIRCUIT DIAGRAM

    bta16 600b transistor

    Abstract: bta16-600b LM317* switching STPS series 2A VOLTAGE REGULATOR TO-220 BTA06-600B bta40-600b application BTA40600B TO-220 transistor package LM338K
    Text: PHOTOCOPIERS RECOMMENDED PRODUCTS FROM SGS-THOMSON POWER SUPPLY Cont’d POWER SUPPLY Type Package L78xx L79xx L78Mxx LM317 LM317MDT LM323 LM337 LM338K LM350K L78Sxx L78Lxx LM723 1.5A Series TO-220/Isowatt 220/TO-3 1.5A Series TO-220/Isowatt 220/TO-3 0.5A Series TO-220/Isowatt 220/DPAK/SOT194/SOT82


    Original
    PDF L78xx L79xx L78Mxx LM317 LM317MDT LM323 LM337 LM338K LM350K L78Sxx bta16 600b transistor bta16-600b LM317* switching STPS series 2A VOLTAGE REGULATOR TO-220 BTA06-600B bta40-600b application BTA40600B TO-220 transistor package LM338K

    Schottky diode TO220 15A 1000V

    Abstract: smd transistor c011 diode matrix rom LM317 DIP PACK transistor SMD 5kw smd L272 bdx54 smd LM317 SMD smps power supply 1500w amp TRANSIL DIODE smd
    Text: DATA LOGGERS RECOMMENDED PRODUCTS FROM SGS-THOMSON PRINT HEAD HAMMER DRIVE Type ULN2003A ULN2064B ULN2068B ULN2074B L702N/A L6221AS L9222 Function High Current Darlington Drivers Medium Current Low Saturation Transistor Array BDX53 BDX54 Series BDW93 & BDW94 Series


    Original
    PDF ULN2003A ULN2064B ULN2068B ULN2074B L702N/A L6221AS L9222 BDX53 BDX54 BDW93 Schottky diode TO220 15A 1000V smd transistor c011 diode matrix rom LM317 DIP PACK transistor SMD 5kw smd L272 bdx54 smd LM317 SMD smps power supply 1500w amp TRANSIL DIODE smd

    L49721

    Abstract: LME49721 L4972 National Semiconductor Audio/Radio Handbook LME49721MA M08A LME49721MAE 1980 Audio Handbook lme49
    Text: LME49721 High Performance, High Fidelity Rail-to-Rail Input/Output Audio Operational Amplifier General Description • Slew Rate The LME49721 is a low distortion, low noise Rail-to-Rail Input/ Output operational amplifier optimized and fully specified for


    Original
    PDF LME49721 LME49721 L49721 L4972 National Semiconductor Audio/Radio Handbook LME49721MA M08A LME49721MAE 1980 Audio Handbook lme49

    sg3525 application note

    Abstract: switching power supply sg3525 sg3524 PWM dc to dc boost regulator sg3524 PWM GENERATOR with mosfet sg3525 pwm dc motor Full-bridge SG3525 sg3525 pwm SG3525 IC sg3525 application sg3525
    Text: Industrial and power conversion ICs Selection guide November 2009 www.st.com Application specific for motor control Controllers Package Vcc V L297D Part number SO-20 5 L297 DIP-20 5 PWM current controller, stepper motor sequence generator, enable input, reset and home input


    Original
    PDF L297D SO-20 DIP-20 L6506D L6506 DIP-18 L6201 L6201PS sg3525 application note switching power supply sg3525 sg3524 PWM dc to dc boost regulator sg3524 PWM GENERATOR with mosfet sg3525 pwm dc motor Full-bridge SG3525 sg3525 pwm SG3525 IC sg3525 application sg3525

    Untitled

    Abstract: No abstract text available
    Text: LME49721 www.ti.com SNAS371C – SEPTEMBER 2007 – REVISED APRIL 2013 LME49721 High-Performance, High-Fidelity Rail-to-Rail Input/Output Audio Operational Amplifier Check for Samples: LME49721 FEATURES DESCRIPTION • • The LME49721 is a low-distortion, low-noise Rail-toRail Input/Output operational amplifier optimized and


    Original
    PDF LME49721 SNAS371C LME49721

    Untitled

    Abstract: No abstract text available
    Text: iZ J L4972A L4972AD S G S -T H O M S O N 2A SWITCHING REGULATOR • ■ ■ . ■ ■ ■ . ■ ■ ■ ■ ■ ■ 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1 V ± 2% ON CHIP REFERENCE


    OCR Scan
    PDF L4972A L4972AD 200KHz L4972A 330pF 330uF t191L49 50KHz 1-80UH 380UH

    Untitled

    Abstract: No abstract text available
    Text: L4972A L4972AD /3T SGS-THOMSON 2A SWITCHING REGULATOR For complete specification refer to ' Linear & Switching Voltage Regulators Appi. Manual V Order Code AMLISVOREST71 • ■ ■ . ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE


    OCR Scan
    PDF L4972A L4972AD AMLISVOREST71 200KHz L4972A

    C1237

    Abstract: LA 4972 c1237 ha MKT 10uf 63v L4970 L4972 L4972D S020 h89a ui35
    Text: 7=12^237 DD225MM 3 H T S 8 - ll- 3 > l L4972 L4972D S G S - T H O M S O N D O ^ O iK L d O I F lH lO lM D O i S G S-THOMSON 30E » 2A SWITCHING REGULATOR A D VA N C E DATA • ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 2A OUTPUT CURRENT 5.1 V TO 40V OUTPUT VOLTAGE RANGE


    OCR Scan
    PDF L4972 L4972D 200KHz V/12V L4970. 33BpF L497B 330pF C1237 LA 4972 c1237 ha MKT 10uf 63v L4970 L4972D S020 h89a ui35

    L4972

    Abstract: L4972D L4970 58310 Eyf 06 ROE ROE capacitor 220 S020 H89L transistor a 1837
    Text: F- SCS-THOMSON L4 9 7 2 L4972D 3.5A SWITCHING REGULATOR A DVANCE DATA • ■ ■ . ■ ■ ■ ■ ■ . ■ ■ ■ 2A OUTPUT CURRENT 5.1 V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORW ARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2 % ON CHIP REFERENCE


    OCR Scan
    PDF L4972 L4972D 200KHz 10OKHz) V/12V L4970. L4972-L4972D L4972D L4970 58310 Eyf 06 ROE ROE capacitor 220 S020 H89L transistor a 1837

    kt183

    Abstract: No abstract text available
    Text: r= 7 S C S -T H O M S O N * 7 # » R fflD ^ Q [ iL i© ci r ( Q ) i O ( g i L4972A L4972AD 2A SWITCHING REGULATOR . 2A OUTPUT CURRENT . 5.1 V TO 40V OUTPUT VOLTAGE RANGE •0 TO 90% DUTY CYCLE RANGE i INTERNAL FEED-FORWARD LINE REG. i INTERNAL CURRENT LIMITING


    OCR Scan
    PDF L4972A L4972AD 200KHz L4970A. 330pF 3300UF 330pF 50KHz kt183

    M6S4

    Abstract: ic cd 5888 diagram
    Text: 5 7 . S G S -T H O M S O N L4972A L4972AD 2A SWITCHING REGULATOR . • ■ . . ■ ■ ■ . ■ . ■ ■ ■ 2A OUTPUT CURRENT 5.1V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1V ± 2% ON CHIP REFERENCE


    OCR Scan
    PDF L4972AD L4972A 200KHz L4972A M6S4 ic cd 5888 diagram

    Untitled

    Abstract: No abstract text available
    Text: SGS-THOMSON lEJgfMODIgi L4972A L4972AD 2A SWITCHING REGULATOR . • . . . . . . . 2A OUTPUT CURRENT 5.1 V TO 40V OUTPUT VOLTAGE RANGE 0 TO 90% DUTY CYCLE RANGE INTERNAL FEED-FORWARD LINE REG. INTERNAL CURRENT LIMITING PRECISE 5.1 V ± 2% ON CHIP REFERENCE


    OCR Scan
    PDF L4972A L4972AD 200KHz L4972Ais

    Untitled

    Abstract: No abstract text available
    Text: LM E49721 LME49721 High Performance, High Fidelity Rail-to-Rail Input/Output Audio Operational Amplifier Texa s In s t r u m e n t s Literature Number: SNAS371B t a l LM E49721 Sem iconductor High P erform ance, High Fidelity R ail-to-R ail In pu t/O u tp ut


    OCR Scan
    PDF E49721 LME49721 SNAS371B

    TDA0161 equivalent

    Abstract: 1N3393 BDX54F equivalent byt301000 bux transient voltage suppressor ST90R9 ua776mh sgs 2n3055 Transistor morocco mje13007 inmos transputer reference manual
    Text: SHORTFORM 1995 NOVEMBER 1994 USE IN LIFE SUPPORT DEVICES OR SYSTEMS MUST BE EXPRESSLY AUTHORIZED SGS-THOMSON PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF SGS-THOMSON Microelectronics. As used herein:


    OCR Scan
    PDF