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t &MFDUSJDBMFRVJWBMFOU to leaded types LA/ZA series t "$7PMUBHF3BUJOH 7UP7"$SNT t /P%F3BUJOHVQ UP¡$BNCJFOU t (PPETPMEFSBCJMJUZ t "WBJMBCMFJOUBQF and reel t "QQMJDBUJPOPG"$ power meters Agency Approvals Absolute Maximum Ratings t'PSSBUJOHTPGJOEJWJEVBMNFNCFSTPGBTFSJFT TFF%FWJDF3BUJOHTBOE4QFDJmDBUJPOTDIBSU Agency Agency File Number Continuous SM7 Series Units Steady State Applied Voltage: "$7PMUBHF3BOHF 7. "$ 3.4) UP V %$7PMUBHF3BOHF 7. %$ ) UP V Transients: Peak Pulse Current (ITM) 'PSμT$VSSFOU8BWF 4FF'JHVSF A 4JOHMF1VMTF&OFSHZ3BOHF 'PSμs Current Wave (WTM) UP J 0QFSBUJOH"NCJFOU5FNQFSBUVSF3BOHF 5A) UP OC 4UPSBHF5FNQFSBUVSF3BOHF 545() UP OC 5FNQFSBUVSF$PFGmDJFOU BV) of Clamping Voltage (VC BU4QFDJmFE5FTU$VSSFOU %/OC )J1PU&ODBQTVMBUJPO $0"5*/(*TPMBUJPO7PMUBHF$BQBCJMJUZ %JFMFDUSJDNVTUXJUITUBOEJOEJDBUFE%$WPMUBHFGPSPOFNJOVUFQFS.*-45% .FUIPE V $0"5*/(*OTVMBUJPO3FTJTUBODF MΩ CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. SM7 Varistor Series
©2010 Littelfuse, Inc. Revision: January 10, 2011 SM7 Series Varistor Surface Mount Varistors > SM7 Series Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information. /05&4.TFSJFTEFWJDFTBSFSFDPHOJ[FEVOEFS6-mMF& SM7 Series Ratings & Specifications Maximum Rating (85°C) Specifications (25°C) Continuous Transient Varistor Voltage at 1mA DC Test Current Maximum Clamping Voltage 8 x 20 μs Typical Capacitance f = 1MHzV3.4 V%$ Energy 10 x 1000μs Peak Current 8 x 20μs Part Number VM(AC) V. %$ WTM I TM V NOM Min V NOM Max V C IPK C (V) (V) (J) (A) (V) (V) (V) (A) (pF) 74. 74. 74. 74. 74. 74. 74. 74. 'PSBQQMJDBUJPOTFYDFFEJOH$BNCJFOUUFNQFSBUVSF UIFQFBL surge current and energy ratings must be reduced as shown below Peak Pulse Current T est Waveform for Clamping VoltagePeak Current, Energy and Power Derating Curve = Virtual Origin of Wave 5JNFGSPNUPPG1FBL T 3JTF5JNF T %FDBZ5JNF Example 'PSBOμT$VSSFOU8BWFGPSN 8μs = T 3JTF5JNF μs = T %FDBZ5JNF PERCENT OF PEAK VALUE Test0 100 TIM E t t Pulse Rating Curves 100 1000 10000 10 100 1000 10000 Impulse Duration (μs) Surge Current (A) 102 103 104 105 106 /05&If pulse ratingsBSFFYDFFEFE BTIJGUPGV/ %$ BUTQFDJmFEDVSSFOU PGNPSFUIBO DPVMESFTVMU5IJTUZQFPGTIJGU XIJDIOPSNBMMZSFTVMUTJOBEFDSFBTFPGV/ %$ NBZ SFTVMUJOUIFEFWJDFOPUNFFUJOHUIFPSJHJOBMQVCMJTIFETQFDJmDBUJPOT CVUJUEPFTOPUQSFWFOU UIFEFWJDFGSPNDPOUJOVJOHUPGVODUJPO BOEUPQSPWJEFBNQMFQSPUFDUJPO V-I Limit Curves 500 1000 1500 2000 0.001 0.01 0.1 1 10 100 1000 Current(A) Voltage(V) V510SM7 V480SM7 V460SM7 V420SM7 V385SM7 V320SM7 V300SM7 100 -55 50 60 70 80 90 100 110 120 130 140 150 AMBIENT TEMPERATURE ( oC) PERCENT OF RATED VALUE
©2010 Littelfuse, Inc. Revision: January 10, 2011 SM7 Series Varistor Surface Mount Varistors > SM7 Series Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information. SM7 Series Lead (Pb) Soldering Recommendations 5IFQSJODJQBMUFDIOJRVFTVTFEGPSUIFTPMEFSJOHPG DPNQPOFOUTJOTVSGBDFNPVOUUFDIOPMPHZBSF*33FnPX BOE8BWFTPMEFSJOH5ZQJDBMQSPmMFTBSFTIPXOPOUIFSJHIU 5IFUFSNJOBMTPG4.TFSJFTEFWJDFTBSFUJOQMBUFEDPQQFS BOEUIFSFDPNNFOEFETPMEFSJT 4O1C"H 4O1C PS 4O1C -JUUFMGVTFBMTPSFDPNNFOETBO 3."TPMEFSnVY Wave soldering is the most strenuous of the processes. To avoid the possibility of generating stresses due to UIFSNBMTIPDL BQSFIFBUTUBHFJOUIFTPMEFSJOHQSPDFTT JTSFDPNNFOEFE BOEUIFQFBLUFNQFSBUVSFPGUIFTPMEFS process should be rigidly controlled. 8IFOVTJOHBSFnPXQSPDFTT DBSFTIPVMECFUBLFOUP ensure that the SM7 chip is not subjected to a thermal HSBEJFOUTUFFQFSUIBOEFHSFFTQFSTFDPOE UIFJEFBM HSBEJFOUCFJOHEFHSFFTQFSTFDPOE%VSJOHUIFTPMEFSJOH QSPDFTT QSFIFBUJOHUPXJUIJOEFHSFFTPGUIFTPMEFShT QFBLUFNQFSBUVSFJTFTTFOUJBMUPNJOJNJ[FUIFSNBMTIPDL 0ODFUIFTPMEFSJOHQSPDFTTIBTCFFODPNQMFUFE JUJT 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$CFGPSFDMFBOJOH Lead–free (Pb-free) Soldering Recommendations 5IFUFSNJOBMTPG4.TFSJFTEFWJDFTBSFUJOQMBUFEDPQQFS BOEUIFSFDPNNFOEFE-FBEGSFFTPMEFSJT 4O"H$V XJUIBO3."nVY UIPVHIUIFSFJTBXJEF TFMFDUJPOPGQBTUFTBOEnVYFTBWBJMBCMFUIBUTIPVMECF compatible. 5IFSFnPXQSPmMFNVTUCFDPOTUSBJOFECZUIFNBYJNVNT JOUIF-FBEoGSFF3FnPX1SPmMF'PS-FBEoGSFF8BWF TPMEFSJOH UIF8BWF4PMEFS1SPmMFTUJMMBQQMJFT /PUFUIF-FBEoGSFFQBTUF nVYBOEQSPmMFXFSFVTFEGPS FWBMVBUJPOQVSQPTFTCZ-JUUFMGVTF CBTFEVQPOJOEVTUSZ standards and practices. There are multiple choices of all UISFFBWBJMBCMF JUJTBEWJTFEUIBUUIFDVTUPNFSFYQMPSFTUIF optimum combination for their process as processes vary considerably from site to site. PREHEAT ZONE PREHEAT DWELL RAMP RATE <2°C/s MAXIMUM TEMPERATURE 230°C TEMPERATURE °C TIME (MINUTES) 250 200 150 100 40-80 SECONDS ABOVE 183°C TIME (MINUTES) 300 250 200 150 100 MAXIMUM WA VE 260°C SECOND PREHEA T FIRST PREHEAT TEMPERATURE °C MAXIMUM TEMPERATURE 250˚C, TIME WITHIN 5˚C OF PEAK
20 SECONDS MAXIMUM
<3˚C/s 60 - 150 SEC > 217˚C TEMPERATURE °C TIME (MINUTES) 300 250 200 150 100 Reflow Solder Profile Wave Solder Profile Lead–free Re-flow Solder Profile
©2010 Littelfuse, Inc. Revision: January 10, 2011 SM7 Series Varistor Surface Mount Varistors > SM7 Series Specifications are subject to change without notice. Please refer to www.littelfuse.com/series/sm7.html for current information. Part Numbering System For “VARISTOR” VM(AC) (Three digits -- 275V to 510V) V 275 SM7 SM7 SERIES T ape & Reel Specifications mm W T A0 B0 K0 E F P0 P1 P2 D0 D1 All dimensions shown in milimeters 6.5 13.1 3.5 Soldering Pad Layout 1 1.5±0.3 8.3±0.3 6.0±0.3 Product Dimensions /05&4 "MMEJNFOTJPOTQFS&*"D QJUDIFTDVNVMBUJWFUPMFSBODFPOUBQFNN 2VBOUJUZQFSJODI NN SFFMQDT A-A B-B 1 1.30 3.60 T 120° Ø21±0.8 2±0.5Ø13±0.2 DETAIL H DETAIL H Ø330 Ø100 16.5 21.5±0.4 Plastic Reel Carrier T ape 6.2 10° F E W P1D0 D1B A BA