MELF RRMMesiesisELELsttFFoorrss Resistors Welwyn Components Resistors WWeellwynwyn ComponentsComponents RReessiiststoorrss MELF MELF RResiesissttoorrss MELF Resistors WRM Series WWRRMM SSeerriieess WRM SeriesWRM SeriesWRM Series High reliability HighHigh rreliabilityeliability High reliability AAEEPC-Q200C-Q200redictable pulse handling capability PPrredictableedictable pulsepulse handlinghandling capabilitycapability Predictable pulse handling capability High High rreliabilityeliability Tolerances down to 0.1% TTolerancesolerances downdown toto 0.1%0.1% Tolerances down to 0.1% PPrredicedicttable pulse handlingable pulse handling ccapabilityapability TCR down to 5 ppm/C TCRTCR downdown toto 55 ppm/Cppm/C TCR down to 5 ppm/C TToleolerrances dances doown wn tto 0.1%o 0.1% TTCR dCR doown wn tto 5 ppm/Co 5 ppm/C All parts are Pb-free and comply with EU Directive 2011/65/EU (RoHS2) Electrical Data ElEleectrctriicacall DDaattaa WRM 0102 WRM 0204 WRM 0207 WRMWRM 01001022 WRMWRM 02002044 WRMWRM 02070207 Power rating at 70C watts PPoowweerr rraattiinngg aatt 7700CC wwaattttss 0.2 0.25 0.4 0.2 0.2 00..2255 00..44 Resistance range ohms 40R - 1M0 R22 5M1 R22 10M RReessiissttaannccee rraannggee oohhmmss 40R - 1M08R2 - 1M0 R22R22 55MM11 RR2222 1010MM Limiting element voltage volts 200 200 250 LLiimmiittiinngg eelleemmeenntt vvoollttaaggee vvoollttss 200200 220000 225500 TCR ppm/C 5,1 0,1 5, 25, 50, 100 15, 25, 50, 100 TTCCRR ppppmm//CC 15, 25, 50, 100 55,,11 00,,11 55,, 2255,, 550, 1000, 100 1155,, 2255,, 550, 1000, 100 15, 25, 50, 10015, 25, 50, 100 Resistance tolerance % RReessiissttaannccee ttoolleerraannccee %% 0.1, 0.25, 0.5, 1, 5 0.1, 0.25, 0.5, 1, 50.1, 0.25, 0.5, 1, 5 Standard values E24 & E96 StandaStandarrdd valuesvalues E24E24 && E96E96 Thermal impedance k/W 250 200 140 TThheerrmmaall iimmppeeddaannccee kk//WW 225500 220000 114400 Ambient temperature range C AAmmbbiieenntt tteemmppeerraattuurree rraannggee CC -55 to +155 -55 to +125 -55 to +155-55 to +155 -55 to +125-55 to +125 10 1010 Insulation resistance ohms >10 IInnssuullaattiioonn rreessiissttaannccee oohhmmss >>1100 Zero ohm jumper current rating amps 2 4 Zero ohm jumper current ratingZero ohm jumper current rating ampsamps 22 44 Zero ohm jumper maximum residual resistance m 15 Zero ohm jumper maximum residual resistanceZero ohm jumper maximum residual resistance mm 1515 Physical Data PhysPhysiicacall DaDattaa Dimensions (mm) and weight (g) Dimensions (mm) and weight (g)DimensionsDimensions (mm)(mm) andand weightweight (g)(g) L LL 1 1 1 Type L D 11 D K Weight Type L D D K L Weight TTypypee LL DD DD KK WWeight eight max max max min maxmamaxx maxmamaxx max mamaxx min minmin min WRM 0102 2.3 1.35 1.3 0.3 1.1 0.01 D D DD DD WRM 0102 2.3 1.35 1.3 0.3 0.01 1 WRMWRM 01020102 0.00.011 11 2.3 2.3 1.35 1.35 1.3 1.3 0.3 0.3 WRM 0204WRM 0204 3.7 3.7 1.55 1.55 0.5 0.01.55 1.55 0.5 1.5 20.02 WRMWRM 02040204 3.3.7 1.55 1.55 0.5 0.07 1.55 1.55 0.5 0.022 1 11 L K LL KK WRM 0207WRM 0207 6.1 6.1 2.4 2.4 2.4 0.5 0.08 2.4 0.5 2.9 0.08 WRMWRM 02070207 6.6.11 2.2.4 2.4 0.5 0.08 4 2.4 0.5 0.08 Construction ConstructionConstruction Terminations A metal film is deposited onto a high dissipation ceramic TTerminationserminations AA metalmetal filmfilm isis depositeddeposited ontoonto aa highhigh dissipationdissipation ceramicceramic Material Plated steel cap. former to which tin plated teminating caps are fitted. MaterialMaterial PlatedPlated steelsteel cap.cap. formerformer toto whichwhich tintin platedplated teminatingteminating capscaps aarree fitted.fitted. Solderability The pure tin finish produces ageing free SolderabilitySolderability TheThe pupurree tintin finishfinish pprroducesoduces ageingageing ffrreeee The resistor is adjusted to value by a helical cut in the film TheThe rresistoresistor isis adjustedadjusted toto valuevalue byby aa helicalhelical cutcut inin thethe filmfilm contacts on which low melting solders can contactscontacts onon whichwhich lowlow meltingmelting solderssolders can can and the body is protected by a lacquer coating. andand thethe bodybody isis pprrotectedotected byby aa lacquerlacquer coating.coating. be used. Dipped area shall be covered with bebe used.used. DippedDipped aarreaea shallshall bebe covecoverreded with with a smooth and bright solder coating after aa smoothsmooth andand brightbright soldersolder coatingcoating afterafter Marking MarkingMarking 3 seconds immersion at 215C. 33 secondsseconds immersionimmersion atat 215C.215C. Resistance values are colour coded with four bands, Resistance values are colour coded with four bands, Resistance values are colour coded with four bands, three indicating value and one indicating the multiplier. three indicating value and one indicating the multiplier.three indicating value and one indicating the multiplier. Solvent Resistance SolventSolvent ResistanceResistance (Note this describes standard marking, but certain values (Note this describes standard marking, but certain values (Note this describes standard marking, but certain values The body protection and marking are resistant to all normal TheThe bodybody pprrotectionotection andand markingmarking aarree rresistantesistant toto allall normalnormal may still be supplied with the addition of a tolerance band may still be supplied with the addition of a tolerance bandmay still be supplied with the addition of a tolerance band industrial cleaning solvents suitable for printed circuit boards. industrialindustrial cleaningcleaning solventssolvents suitablesuitable forfor printedprinted cicirrcuitcuit boaboarrds.ds. following the multiplier.) following the multiplier.)following the multiplier.) GeneGenerral Noal Nottee General Note BI BI TBI TTechnologies Iechnologies IRechnologies IRRC C WC WWelwynelwynelwyn TT Electronics reserves the right to make changes in product specification without notice or liability. All inAll infformation is suormation is subbject to TT Electronics own daject to TT Electronics own datta and is considered accua and is considered accurraatte at time of going to print.e at time of going to print. All information is subject to TT Electronics own data and is considered accurate at time of going to print. www.twww.tttelectronics.com/resistorselectronics.com/resistors www.ttelectronics.com/resistors TT Electronics plc TT Electronics plc TT Electronics plc 11.1703.18 09.17MELFMELF MELFMELF MELF Resistors Resistors RResiesissttoorrss Resistors WRM Series WRM SeriesWRM Series WRM Series Welwyn Components WRM Series MELFMELF MELF MELF RResiesissttoorrss Resistors TRCesRis atonrds Tolerance Range WRM Series WRM Series WRM Series Welwyn Components WRM Series Type TCR Tolerance Reference 5% 1.0% 0.5% 0.25% 0.1% 100ppm 10R - 1M0 10R - 1M0 - - - TCR and Tolerance Range 50ppm 10R - 1M0 10R - 1M0 8R2 - 1M0 - - WRM0102 25ppm - 100R - 82K 100R - 100K 100R - 82K 100R - 82K Type TCR Tolerance 15ppm - 100R - 56K 100R - 56K 100R - 56K 100R - 56K Reference 100ppm R22 R91 - - - - 5% 1.0% 0.5% 0.25% 0.1% 50ppm - 1R 5M1 10R 1M6 22R 332K 43R 332K 100ppm 10R - 1M0 10R - 1M0 - - - 25ppm - 4R7 500K 10R 500K 22R 402K 43R 332K WRM0204 50ppm 10R - 1M0 10R - 1M0 8R2 - 1M0 - - WRM0102 15ppm - - 10R 221K 22R 221K 43R 221K 25ppm - 100R - 82K 100R - 100K 100R - 82K 100R - 82K 10ppm - - - 22R 221K 43R 221K 15ppm - 100R - 56K 100R - 56K 100R - 56K 100R - 56K 05ppm - - - 100R 100K 100R 100K 100ppm R22 R91 - - - - 100ppm R22 R91 - - - - 50ppm - 1R 5M1 10R 1M6 22R 332K 43R 332K 50ppm - 1R-10M 10R - 1M6 - - 25ppm - 4R7 500K 10R 500K 22R 402K 43R 332K WRM0207 WRM0204 25ppm - 10R - 1M 10R 680K 51R1 - 330K 100R - 100K 15ppm - - 10R 221K 22R 221K 43R 221K 15ppm - - 51R1 - 10K 51R1 - 10K 100R - 10K 10ppm - - - 22R 221K 43R 221K 05ppm - - - 100R 100K 100R 100K * TC 10ppm & 5ppm is specied over the temperature range -10C to +85C. 100ppm R22 R91 - - - - 50ppm - 1R-10M 10R - 1M6 - - Performance Data WRM0207 25ppm - 10R - 1M 10R 680K 51R1 - 330K 100R - 100K Test Results R/R 15ppm - - R/R 51R1 - 10K 51R1 - 10K 100R - 10K 0204 and 0207 0102 * TC 10ppm & 5ppm is specied over the temperature range -10C to +85C.0204 & 0207: 10R - <75R 0102: 40R - 1M0, 0204 & Test 0204 & 0207: 75R - 100K & >100K - 332K 0207: R22 - <10R & >332K - 10M 10R - <75R & 75R 100K <10R & >332K All values Short time overload* 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 >100K - 332K Performance Data Bending test* 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 Short me overload* 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 0.25% + 0.05 Test Results R/R Resistance to soldering heat 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 Bending test* 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 0.25% + 0.05 0204 & 0207: 10R - <75R 0102: 40R - 1M0, 0204 & Temperature rapid change 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 0204 & 0207: 75R - 100K Resistance to soldering & >100K - 332K 0207: R22 - <10R & >332K - 10M 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 0.25% + 0.05 Endurance* heat Short time overload* 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 Load life 1000h 0.25% + 0.05 0.25% + 0.05 0.5% + 0.05 Temperature rapid Bending test* 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 0.25% + 0.05 8000 h 0.5% + 0.05 0.5% + 0.05 1.0% + 0.05 change Resistance to soldering heat 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 Climatic sequence* 0.25% + 0.05 0.5% + 0.05 1.0% + 0.05 Endurance* Temperature rapid change 0.05% + 0.01 0.1% + 0.01 0.25% + 0.05 Damp heat steady state* 0.25% + 0.05 0.5% + 0.05 1.0% + 0.05 Load life 1000 h 0.15% + 0.05 0.15% + 0.05 0.3% + 0.05 0.5% + 0.05 Endurance* Current noise < 0.05 V/V < 0.25 V/V < 3 V/V 8000h 0.3% + 0.05 0.3% + 0.05 0.6% + 0.05 1.0% + 0.05 Load life 1000h 0.25% + 0.05 0.25% + 0.05 0.5% + 0.05 Solderability Dipped area shall be covered with a smooth 225,000h 0.9% + 0.05 0.9% + 0.05 1.8% + 0.05 3.0% + 0.05 8000 h 0.5% + 0.05 0.5% + 0.05 1.0% + 0.05 and bright solder coating of at least 96% Climac sequence* 0.25% + 0.05 0.5% + 0.05 1.0% + 0.05 1.0% + 0.05 Climatic sequence* 0.25% + 0.05 0.5% + 0.05 1.0% + 0.05 6 Voltage coefficient < 0.5 . 10 /V Damp heat steady Damp heat steady state* 0.25% + 0.05 0.5% + 0.05 1.0% + 0.05 0.25% + 0.05 0.5% + 0.05 1.0% + 0.05 1.0% + 0.05 Voltage proof No flashover or breakdown state* Current noise < 0.05 V/V < 0.25 V/V < 3 V/V * Resistors to be mounted on a PC-board according to IEC 115-1, clause 4.27.1 Current noise <0.05V/V <0.25V/V <3V/V <3V/V Solderability Dipped area shall be covered with a smooth * AEC-Q200 approval applies to all values up to and including 3M4 at TCRs above 5ppm/C and to zero ohm jumpers Solderability >95% coverage and bright solder coating of at least 96% 6 Voltage coe cient 0 to -0.5ppm/V Voltage coefficient < 0.5 . 10 /V VVoollttaaggee pprrooooff No ashoNo flashover or breakdownver or breakdown * Resistors to be mounted on a PC-board according to IEC 115-1, clause 4.27.1 * AEC-Q200 approval applies to all values up to and including 3M4 at TCRs above 5ppm/C and to zero ohm jumpers GeneGenerral Noal Nottee GeneGenerral Noal Nottee BI Technologies IRC Welwyn BI Technologies IRC Welwyn BI BI TTechnologies Iechnologies IRRC C WWelwynelwyn TT Electronics reserves the right to make changes in product specification without notice or liability. All inAll infformation is suormation is subbject to TT Electronics own daject to TT Electronics own datta and is considered accua and is considered accurraatte at time of going to print.e at time of going to print. All inAll infformation is suormation is subbject to TT Electronics own daject to TT Electronics own datta and is considered accua and is considered accurraatte at time of going to print.e at time of going to print. www.ttelectronics.com/resistors www.twww.twww.ttttelectronics.com/resistorselectronics.com/resistorselectronics.com/resistors Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK TT Electronics plc TT Electronics plc TT Electronics plc TT Electronics plc Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info welwyn-tt.com Website: www.welwyn-tt.com 01.11 11.17 09.1703.1703.18 GeneGenerral Noal Nottee General Note BI BI TTechnologies Iechnologies IRRC C WWelwynelwyn BI Technologies IRC Welwyn All inAll infformation is suormation is subbject to TT Electronics own daject to TT Electronics own datta and is considered accua and is considered accurraatte at time of going to print.e at time of going to print. All information is subject to TT Electronics own data and is considered accurate at time of going to print. www.ttelectronics.com/resistors www.twww.tttelectronics.com/resistorselectronics.com/resistors Welwyn Components Limited Bedlington, Northumberland NE22 7AA, UK TT Electronics plc TT Electronics plc TT Electronics plc Telephone: +44 (0) 1670 822181 Facsimile: +44 (0) 1670 829465 Email: info welwyn-tt.com Website: www.welwyn-tt.com 01.11 11.17 09.1703.17