Varistor Products Surface Mount Varistors > SM7 Series RoHS SM7 Varistor Series Description The Littelfuse SM7 Series is a plastic-encapsulated surface-mount metal oxide varistor (MOV) transient voltage surge suppressor that is designed to be operated continuously across AC power lines. The series comprises a Nylon molded package with tin plated lead frame for soldering to board. The surface mount SM7 Series is based on radial 7mm internal varistor element with similar characteristics to the Littelfuse LA / ZA series of varistor. Features Agency Approvals Agency Agency File Number & t &MFDUSJDBMFRVJWBMFOU to leaded types LA/ZA series t (PPETPMEFSBCJMJUZ t "$7PMUBHF3BUJOH 7UP7"$SNT t "QQMJDBUJPOPG"$ power meters t "WBJMBCMFJOUBQF and reel SM7 Series t /P%F3BUJOHVQ UP¡$BNCJFOU Absolute Maximum Ratings t'PSSBUJOHTPGJOEJWJEVBMNFNCFSTPGBTFSJFTTFF%FWJDF3BUJOHTBOE4QFDJmDBUJPOTDIBSU Continuous SM7 Series Units "$7PMUBHF3BOHF7."$ 3.4) UP V %$7PMUBHF3BOHF7.%$ ) UP V A Steady State Applied Voltage: Transients: Peak Pulse Current (ITM) 'PSμT$VSSFOU8BWF4FF'JHVSF 4JOHMF1VMTF&OFSHZ3BOHF UP 'PSμs Current Wave (WTM) J 0QFSBUJOH"NCJFOU5FNQFSBUVSF3BOHF5A) UP O 4UPSBHF5FNQFSBUVSF3BOHF545() UP O C C 5FNQFSBUVSF$PFGmDJFOUBV) of Clamping Voltage (VC BU4QFDJmFE5FTU$VSSFOU %/OC )J1PU&ODBQTVMBUJPO$0"5*/(*TPMBUJPO7PMUBHF$BQBCJMJUZ %JFMFDUSJDNVTUXJUITUBOEJOEJDBUFE%$WPMUBHFGPSPOFNJOVUFQFS.*-45%.FUIPE V $0"5*/(*OTVMBUJPO3FTJTUBODF MΩ CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. ©2010 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information. SM7 Series Varistor Revision: January 10, 2011 Varistor Products Surface Mount Varistors > SM7 Series SM7 Series Ratings & Specifications Maximum Rating (85°C) Continuous Transient Part Number 74. 74. 74. 74. 74. 74. 74. 74. V3.4 V%$ VM(AC) (V) V.%$ (V) Specifications (25°C) Maximum Clamping Energy Peak Current Voltage 10 x 1000μs 8 x 20μs 8 x 20 μs WTM ITM VNOM Min VNOM Max VC IPK (J) (A) (V) (V) (V) (A) Varistor Voltage at 1mA DC Test Current Typical Capacitance f = 1MHz C (pF) /05&4.TFSJFTEFWJDFTBSFSFDPHOJ[FEVOEFS6-mMF& Peak Current, Energy and Power Derating Curve Peak Pulse Current Test Waveform for Clamping Voltage PERCENT OF PEAK VALUE Test 'PSBQQMJDBUJPOTFYDFFEJOH$BNCJFOUUFNQFSBUVSFUIFQFBL surge current and energy ratings must be reduced as shown below PERCENT OF RATED VALUE 100 90 80 70 60 50 40 100 50 0 t O1 TIM E t1 30 20 t 10 0 -55 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE ( oC) 130 = Virtual Origin of Wave 55JNFGSPNUPPG1FBL T3JTF5JNFY5 T%FDBZ5JNF Example 'PSBOμT$VSSFOU8BWFGPSN 8μs = T3JTF5JNF μs = T%FDBZ5JNF 140 150 V-I Limit Curves Pulse Rating Curves 2000 V510SM7 V480SM7 10000 V460SM7 1500 V385SM7 V320SM7 1000 V300SM7 500 0 0.001 1 1000 Surge Current (A) Voltage(V) V420SM7 2 104 10 105 2 100 10 103 106 10 0.01 0.1 1 10 100 1000 Current(A) 1 10 /05&If pulse ratingsBSFFYDFFEFEBTIJGUPGV/%$ BUTQFDJmFEDVSSFOU PGNPSFUIBO DPVMESFTVMU5IJTUZQFPGTIJGUXIJDIOPSNBMMZSFTVMUTJOBEFDSFBTFPGV/%$ NBZ SFTVMUJOUIFEFWJDFOPUNFFUJOHUIFPSJHJOBMQVCMJTIFETQFDJmDBUJPOTCVUJUEPFTOPUQSFWFOU UIFEFWJDFGSPNDPOUJOVJOHUPGVODUJPOBOEUPQSPWJEFBNQMFQSPUFDUJPO 100 1000 10000 Impulse Duration (μs) ©2010 Littelfuse, Inc. SM7 Series Varistor Revision: January 10, 2011 Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information. Varistor Products Surface Mount Varistors > SM7 Series Lead (Pb) Soldering Recommendations 5IFQSJODJQBMUFDIOJRVFTVTFEGPSUIFTPMEFSJOHPG DPNQPOFOUTJOTVSGBDFNPVOUUFDIOPMPHZBSF*33FnPX BOE8BWFTPMEFSJOH5ZQJDBMQSPmMFTBSFTIPXOPOUIFSJHIU Reflow Solder Profile 250 0ODFUIFTPMEFSJOHQSPDFTTIBTCFFODPNQMFUFEJUJT still necessary to ensure that any further thermal shocks are avoided. One possible cause of thermal shock is hot printed circuit boards being removed from the solder process and subjected to cleaning solvents at room temperature. The boards must be allowed to cool gradually UPMFTTUIBO$CFGPSFDMFBOJOH 40-80 SECONDS ABOVE 183°C 150 RAMP RATE <2°C/s 100 PREHEAT DWELL 50 0 PREHEAT ZONE 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 TIME (MINUTES) Wave Solder Profile 300 MAXIMUM WAVE 260°C 250 200 150 SM7 Series 8IFOVTJOHBSFnPXQSPDFTTDBSFTIPVMECFUBLFOUP ensure that the SM7 chip is not subjected to a thermal HSBEJFOUTUFFQFSUIBOEFHSFFTQFSTFDPOEUIFJEFBM HSBEJFOUCFJOHEFHSFFTQFSTFDPOE%VSJOHUIFTPMEFSJOH QSPDFTTQSFIFBUJOHUPXJUIJOEFHSFFTPGUIFTPMEFShT QFBLUFNQFSBUVSFJTFTTFOUJBMUPNJOJNJ[FUIFSNBMTIPDL TEMPERATURE °C Wave soldering is the most strenuous of the processes. To avoid the possibility of generating stresses due to UIFSNBMTIPDLBQSFIFBUTUBHFJOUIFTPMEFSJOHQSPDFTT JTSFDPNNFOEFEBOEUIFQFBLUFNQFSBUVSFPGUIFTPMEFS process should be rigidly controlled. MAXIMUM TEMPERATURE 230°C 200 TEMPERATURE °C 5IFUFSNJOBMTPG4.TFSJFTEFWJDFTBSFUJOQMBUFEDPQQFS BOEUIFSFDPNNFOEFETPMEFSJT4O1C"H 4O1C PS4O1C -JUUFMGVTFBMTPSFDPNNFOETBO 3."TPMEFSnVY SECOND PREHEAT 100 FIRST PREHEAT 50 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 TIME (MINUTES) 3.5 4.0 4.5 Lead–free (Pb-free) Soldering Recommendations 5IFSFnPXQSPmMFNVTUCFDPOTUSBJOFECZUIFNBYJNVNT JOUIF-FBEoGSFF3FnPX1SPmMF'PS-FBEoGSFF8BWF TPMEFSJOHUIF8BWF4PMEFS1SPmMFTUJMMBQQMJFT /PUFUIF-FBEoGSFFQBTUFnVYBOEQSPmMFXFSFVTFEGPS FWBMVBUJPOQVSQPTFTCZ-JUUFMGVTFCBTFEVQPOJOEVTUSZ standards and practices. There are multiple choices of all UISFFBWBJMBCMFJUJTBEWJTFEUIBUUIFDVTUPNFSFYQMPSFTUIF optimum combination for their process as processes vary considerably from site to site. Lead–free Re-flow Solder Profile 300 ©2010 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information. MAXIMUM TEMPERATURE 250˚C, TIME WITHIN 5˚C OF PEAK 20 SECONDS MAXIMUM 250 TEMPERATURE °C 5IFUFSNJOBMTPG4.TFSJFTEFWJDFTBSFUJOQMBUFEDPQQFS BOEUIFSFDPNNFOEFE-FBEGSFFTPMEFSJT 4O"H$V XJUIBO3."nVYUIPVHIUIFSFJTBXJEF TFMFDUJPOPGQBTUFTBOEnVYFTBWBJMBCMFUIBUTIPVMECF compatible. RAMP RATE <3˚C/s 200 60 - 150 SEC > 217˚C 150 100 PREHEAT ZONE 50 0 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 TIME (MINUTES) SM7 Series Varistor Revision: January 10, 2011 Varistor Products Surface Mount Varistors > SM7 Series Part Numbering System Product Dimensions 11.5±0.3 V 275 SM7 8.3±0.3 0.3 max For “VARISTOR” (Three digits -- 275V to 510V) 1.5±0.3 6.5 V M(AC) 6.0±0.3 SM7 SERIES 3.0±0.3 All dimensions shown in milimeters 3.5 13.1 Soldering Pad Layout Tape & Reel Specifications mm W T E A0 F Carrier Tape B0 K0 E P0 B D1 B 3.60 W A B0 D0 A 5° P1 P2 T A0 11.30 10° 5° 6.2 K0 2 B-B F P0 P1 P2 D0 D1 /05&4 "MMEJNFOTJPOTQFS&*"D QJUDIFTDVNVMBUJWFUPMFSBODFPOUBQFNN 2VBOUJUZQFSJODINN SFFMQDT A-A Plastic Reel DETAIL H Ø 2±0.5 .2 ±0 13 ±0.8 Ø330 Ø100 Ø21 R1 16.5 120° DETAIL H 21.5±0.4 ©2010 Littelfuse, Inc. SM7 Series Varistor Revision: January 10, 2011 Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information.