Surface Mount Fuses Thin Film > 0603 Size > Fast-Acting > 494 Series 494 Series Fuse, NRA Special Series Integrated Circuit Protector ® Description Features t $PNQBUJCMFXJUIMFBE GSFFTPMEFSTBOEIJHIFS UFNQFSBUVSFQSPåMFT Agency Approvals AGENCY AGENCY FILE NUMBER AMPERE RANGE E10480 250mA - 5A LR29862 250mA - 5A ® t )JHIQFSGPSNBODF NBUFSJBMTQSPWJEF t .PVOUJOHQBEBOE JNQSPWFEQFSGPSNBODF FMFDUSJDBMQFSGPSNBODFBSF JOFMFWBUFEBNCJFOU JEFOUJDBMUP-JUUFMGVTF UFNQFSBUVSFBQQMJDBUJPOT BOE4FSJFTQSPEVDUT t .BSLFEPOUPQTVSGBDF t XJUIDPEFUPBMMPXBNQFSF SBUJOHJEFOUJåDBUJPO XJUIPVUUFTUJOH Electrical Characteristics for Series % of Ampere Rating Opening Time at 25OC IPVST.JOJNVN TFD.BYJNVN TFD.BYJNVN t &MFNFOUDPWFSJOHNBUFSJBM JTSFTJTUBOUUPJOEVTUSZ TUBOEBSEDMFBOJOH PQFSBUJPOT t -PXQSPåMFGPSIFJHIU TFOTJUJWFBQQMJDBUJPOT "MMPZCBTFEFMFNFOU DPOTUSVDUJPOQSPWJEFT TVQFSJPSJOSVTIXJUITUBOE DIBSBDUFSJTUJDT*2U PWFS DFSBNJDPSHMBTTCBTFE GVTFQSPEVDUT t 'MBUUPQTVSGBDFGPSQJDL BOEQMBDFPQFSBUJPOT Applications 4FDPOEBSZQSPUFDUJPOGPSTQBDFDPOTUSBJOFEBQQMJDBUJPOT t $FMMQIPOFT t #BUUFSZQBDLT t %JHJUBMDBNFSBT t )BSEEJTL ESJWFT t %7%QMBZFST Electrical Specifications by Item Agency Approvals Nom Power Dissipation ® (W) Nominal Cold Resistance (Ohms) Nominal Melting I2t (A2sec) Nom Voltage Drop (mV) Y Y Y Y Y Y Y Ampere Rating (A) Amp Code Max Voltage Rating (V) Interrupting Rating "!7"$%$ Y Y Y Y Y Y Y Y Y Y Y Y "!7"$%$ Y Y Y Y Y Y Y Y Y 1. Measured at 10% of rated current, 25ºC. © 2009 Littelfuse, Inc. 2. Measured at rated voltage. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/494.html for current information. 1 Revised: July 6, 2009 494 Series 494 Series 5IF944FSJFT'BTU"DUJOH4.'JTBOVMUSBTNBMM TJ[F UIJOåMNEFWJDFEFTJHOFEGPSTFDPOEBSZQSPUFDUJPO PGDJSDVJUTVTFEJOTQBDFDPOTUSBJOFEBQQMJDBUJPOTTVDI BTIBOEIFMEQPSUBCMFFMFDUSPOJDEFWJDFT5IJTTFSJFTJT MFBEGSFFBOENFFUTUIFSFRVJSFNFOUTPGUIF3P)4 EJSFDUJWF/FX)BMJEF'SFF4FSJFTGVTFTBSFBWBJMBCMF UPPSEFSVTJOHUIFi)'wTVGåY4FF1BSU/VNCFSJOHTFDUJPO GPSBEEJUJPOBMJOGPSNBUJPO Mount Fuses IntroductionSurface to Circuit Protection Thin Film > 0603 Size > Fast-ActingTransientology > 494 Series 1.75 A 2.00 A 2.50 A 3.00 A 3.50 A 4.00 A 5.00 A 0.750 A 1.00 A 1.25 A 1.50 A 0.375 A 0.500 A Average Time Current Curves 0.250 A Temperature Rerating Curve 100 TIME IN SECONDS 10 1 0.1 0.01 0.001 0.1 1 10 CURRENT IN AMPERES 100 Soldering Parameters Pre Heat 1CoGSFFBTTFNCMZ - Temperature Min (Ts(min)) ¡$ - Temperature Max (Ts(max)) ¡$ - Time (Min to Max) (ts) oTFDPOET Average Ramp-up Rate (Liquidus Temp (TL) to peak) ¡$TFDPOENBY TS(max) to TL - Ramp-up Rate ¡$TFDPOENBY Reflow - Temperature (TL) (Liquidus) ¡$ - Temperature (tL) oTFDPOET Peak Temperature (TP) ¡$ Time within 5°C of actual peak Temperature (tp) oTFDPOET Ramp-down Rate ¡$TFDPOENBY Time 25°C to peak Temperature (TP) NJOVUFTNBY Do not exceed ¡$ 494 Series tP TP Critical Zone TL to TP Ramp-up TL TS(max) Temperature Reflow Condition tL Ramp-down TS(min) Preheat tS 25 time to peak temperature (t 25ºC to peak) 2 Time © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/494.html for current information. Surface Mount Fuses Thin Film > 0603 Size > Fast-Acting > 494 Series Product Characteristics Materials Body: "EWBODFE)JHI5FNQFSBUVSF4VCTUSBUF Terminations:5JOPWFS/JDLFMPWFS$PQQFS Element Cover Coat: $POGPSNBM$PBUJOH Operating Temperature o¡$UP¡$$POTVMUUFNQFSBUVSFSFSBUJOH DVSWFDIBSU'PSPQFSBUJPOBCPWF¡$DPOUBDU -JUUFMGVTF Humidity .*-45%'.FUIPE#$POEJUJPO% 8JUITUBOETDZDMFTPGo¡$UP¡$ Vibration 1FS.*-45%' Insulation Resistance (After Opening) (SFBUFSUIBOPINT Resistance to Soldering Heat 8JUITUBOETTFDPOETBCPWF¡$ BOEVQUP¡$NBYJNVN Part Marking System 1.60 (.063") .127 (.005") .305 (.012") Sn Coating .279 (.011") MARKING CODE VARIES WITH AMPERAGE RATING (SEE CHART) Sn Cu .18 R (.007") .813 (.032") REF. Sn 1.09 (.043") 1.02 (.040") 3.20 (.126") 1.09 (.043") WAVE SOLDER 2.54 (.100") 1.02 (.040") .762 (.030") 1.09 (.043") REFLOW SOLDER Amp Code Marking Code D E F G H J K L N O P R S T 494 Series Dimensions Thermal Shock Part Numbering System 0494002.NRHF SERIES AMP Code 3FGFSUP"NQ$PEFDPMVNOJOUIF &MFDUSJDBM4QFDJåDBUJPOTUBCMF /05&5IFEPUJTQPJTJUJPOFECFGPSF UIF1BDLBHJOH4VGåYXJUIXIPMF SBUJOHTBOEXJUIJOUIFOVNCFSJOH TFRVFODFGPSGSBDUJPOBMSBUJOHT PACKAGING Code /35BQFBOE3FFMQDT ‘HF’ SUFFIX HALIDE FREE ITEM Packaging Packaging Option Packaging Specification Quantity Quantity & Packaging Code NN5BQFBOE3FFM &*"34*&$QBSU /3 © 2009 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/494.html for current information. 3 494 Series Introduction to Circuit Protection Transientology 4 © 2009 Littelfuse, Inc. Specifications are subject to change without notice.