Metal-Oxide Varistors (MOVs) Surface Mount Varistors > SM7 Series SM7 Varistor Series RoHS Description The Littelfuse SM7 is a plastic-encapsulated surface mount MOV in a PPS material molded package with tin-plated terminal which is fully qualified in lead free soldering and available for both reflow and wave soldering process. SM7 is constructed with 7mm varistor element disc. Its maximum operating ambient temperature is 85ºC with peak pulse current of 1200A. Features Agency Approvals Agency • Electrical equivalent to leaded types LA/ZA series • Good solderability • Available in tape and reel Agency Approval Agency File Number • AC Voltage Rating 50 to 510VAC rms • UL1449 E320116 Application of AC power meters • No De-Rating up to 85°C ambient • Lead free and RoHS compliant Absolute Maximum Ratings • For ratings of individual members of a series, see Device Ratings and Specifications chart Continuous SM7 Series Units Steady State Applied Voltage: AC Voltage Range (VM(AC)RMS) 50 to 510 V DC Voltage Range (VM(DC)) 68 to 675 V 1200 A Transients: Peak Pulse Current (ITM) For 8/20µs Current Wave (See Figure 2) Single Pulse Energy Range For 10/1000µs Current Wave (WTM) 10 to 40 J Operating Ambient Temperature Range (TA) -40 to +85 O Storage Temperature Range (TSTG) -55 to +125 O C C Temperature Coefficient (aV) of Clamping Voltage (VC) at Specified Test Current <0.01 %/OC Hi-Pot Encapsulation (COATING Isolation Voltage Capability) (Dielectric must withstand indicated DC voltage for one minute per MIL-STD 202, Method 301) 2500 V COATING Insulation Resistance 1000 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. Additional Information Datasheet Resources © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16 Samples Metal-Oxide Varistors (MOVs) Surface Mount Varistors > SM7 Series SM7 Series Ratings & Specifications Maximum Rating (85°C) Continuous Transient Part Number V50SM7 V60SM7 V115SM7 V130SM7 V140SM7 V150SM7 V175SM7 V230SM7 V250SM7 V275SM7 V300SM7 V320SM7 V385SM7 V420SM7 V460SM7 V480SM7 V510SM7 VRMS VDC VM(AC) (V) 50 60 115 130 140 150 175 230 250 275 300 320 385 420 460 480 510 VM(DC) (V) 68 81 153 175 180 200 225 300 330 369 405 420 505 560 615 640 675 Energy Peak Current 10 x 1000µs 8 x 20µs WTM (J) 4 5 10 11 12 13 15 20 21 23 25 25 27 30 37 35 40 ITM (A) 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 1200 Varistor Voltage at 1mA DC Test Current VNOM Min (V) 73 90 162 184 198 212 247 324 354 389 420 462 558 610 640 670 735 VNOM Max (V) 91 110 198 228 242 268 303 396 429 473 517 565 682 748 790 825 910 3.6+/-0.3 for V50SM7-V60SM7 0.3 max 6.5 13.1 VC (V) 135 165 300 340 360 395 455 595 650 710 775 850 1025 1120 1190 1240 1200 IPK (A) 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 10 Typical Capacitance f = 1MHz C (pF) 700 600 200 180 160 150 130 100 90 80 70 65 60 55 55 50 45 V 275 SM7 8.3±0.3 1.5±0.3 Maximum Clamping Voltage 8 x 20 µs Part Numbering System Product Dimensions 11.4±0.3 Specifications (25°C) 6.0+/-0.3 for V115SM7 to V510SM7 3.0±0.3 3.5 All dimensions shown in milimeters For “VARISTOR” VM(AC) (50V to 510V -- 115V to 510V) SM7 SERIES Soldering Pad Layout © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16 Metal-Oxide Varistors (MOVs) Surface Mount Varistors > SM7 Series Lead (Pb) Soldering Recommendations Wave soldering is the most strenuous of the processes. To avoid the possibility of generating stresses due to thermal shock, a preheat stage in the soldering process is recommended, and the peak temperature of the solder process should be rigidly controlled. When using a reflow process, care should be taken to ensure that the SM7 chip is not subjected to a thermal gradient steeper than 4 degrees per second; the ideal gradient being 2 degrees per second. During the soldering process, preheating to within 100 degrees of the solder's peak temperature is essential to minimize thermal shock. Once the soldering process has been completed, it is 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 to less than 50ºC before cleaning. 250 MAXIMUM TEMPERATURE 230°C 200 250 TEMPERATURE °C TEMPERATURE °C The terminals of SM7 series devices are tin plated copper, and the recommended solder is 62/36/2 (Sn/Pb/Ag), 60/40 (Sn/Pb) or 63/37 (Sn/Pb). Littelfuse also recommends an RMA solder flux. Reflow Solder Profile 40-80 MAXIMUM TEMPERATURE SECONDS 230°C ABOVE 183°C 150 200 RAMP RATE40-80 <2°C/s SECONDS ABOVE 183°C 100 150 PREHEAT DWELL RAMP RATE <2°C/s PREHEAT ZONE PREHEAT DWELL 50 100 0 50 0 0.5 PREHEAT ZONE 1.0 1.5 2.0 2.5 3.0 3.5 4.0 3.5 4.0 TIME (MINUTES) 0 0 0.5 1.0 1.5 2.0 2.5PROFILE 3.0 SOLDER FIGURE 14. REFLOW Wave Solder Profile TIME (MINUTES) FIGURE 14. REFLOW SOLDER PROFILE 300 MAXIMUM WAVE 260°C 250 300 TEMPERATURE °C TEMPERATURE °C The principal techniques used for the soldering of components in surface mount technology are IR Re-flow and Wave soldering. Typical profiles are shown on the right. 200 250 MAXIMUM WAVE 260°C 150 200 SECOND PREHEAT 100 150 FIRST PREHEAT SECOND PREHEAT 50 100 0 500.0 0 0.0 Lead–free (Pb-free) Soldering Recommendations 0.5 1.0 FIRST PREHEAT 1.5 2.0 2.5 3.0 TIME (MINUTES) 3.5 4.0 4.5 0.5 1.0 15.1.5 2.5 PROFILE 3.0 3.5 FIGURE WAVE2.0SOLDER TIME (MINUTES) 4.0 4.5 FIGURE 15. WAVE SOLDER PROFILE The reflow profile must be constrained by the maximums in the Lead–free Reflow Profile. For Lead–free Wave soldering, the Wave Solder Profile still applies. Note: the Lead–free paste, flux and profile were used for evaluation purposes by Littelfuse, based upon industry standards and practices. There are multiple choices of all three available, it is advised that the customer explores the optimum combination for their process as processes vary considerably from site to site. Lead–free Re-flow Solder Profile 300 MAXIMUM TEMPERATURE 250˚C, TIME WITHIN 5˚C OF PEAK 20 SECONDS MAXIMUM 250 300 TEMPERATURE °C TEMPERATURE °C The terminals of SM7 series devices are tin plated copper, and the recommended Lead-free solder is 96.5/3.0/0.5 (SnAgCu) with an RMA flux, though there is a wide selection of pastes and fluxes available that should be compatible. RAMP RATE MAXIMUM TEMPERATURE 250˚C, <3˚C/s TIME WITHIN 5˚C OF PEAK 20 SECONDS MAXIMUM 200 250 RAMP RATE <3˚C/s 150 200 100 150 60 - 150 SEC > 217˚C 60 - 150 SEC > 217˚C PREHEAT ZONE 50 100 PREHEAT ZONE 0 50 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 TIME (MINUTES) 0 SOLDER PROFILE 0 FIGURE 1.0 16. LEAD-FREE 2.0 3.0 RE-FLOW 4.0 5.0 6.0 7.0 TIME (MINUTES) FIGURE 16. LEAD-FREE RE-FLOW SOLDER PROFILE © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16 Metal-Oxide Varistors (MOVs) Surface Mount Varistors > SM7 Series For applications exceeding 85ºC ambient temperature, the peak surge current and energy ratings must be reduced as shown below Peak Pulse Current Test Waveform for Clamping Voltage PERCENT OF PEAK VALUE Test Peak Current, Energy and Power Derating Curve PERCENT OF RATED VALUE 100 90 80 70 60 50 40 50 0 t O1 30 TIM E t1 20 t2 10 0 -55 50 60 70 80 90 100 110 120 130 01 = Virtual Origin of Wave T = Time from 10% to 90% of Peak T1 = Rise Time = 1.25 x T T2 = Decay Time Example - For an 8/20 µs Current Waveform: 8µs = T1 = Rise Time 20µs = T2 = Decay Time 140 150 AMBIENT TEMPERATURE ( oC) FIGURE 1. CURRENT, ENERGY AND POWER DERATING CURVE V-I Limit Curves V510SM7 V480SM7 V460SM7 V420SM7 V385SM7 V320SM7 V300SM7 V250SM7 V230SM7 V210SM7 V190SM7 V175SM7 V150SM7 V140SM7 V130SM7 V115SM7 1500 1000 500 0 0.001 0.01 0.1 1 10 100 1000 Current(A) NOTE: If pulse ratings are exceeded, a shift of VN(DC) (at specified current) of more than ±10% could result. This type of shift, which normally results in a decrease of VN(DC), may result in the device not meeting the original published specifications, but it does not prevent the device from continuing to function, and to provide ample protection. Physical Specifications Pulse Rating Curves 10000 1 1000 Surge Current (A) 2000 Voltage(V) 100 2 104 10 100 105 102 103 106 10 1 10 100 1000 10000 Impulse Duration (µs) Environmental Specifications Lead Material Folded Tin Plated Metal Leads Operating Ambient Temperature Range (TA) -40°C to +85°C Soldering Characteristics J-STD-002 Storage Temperature Range(TSTG) -55°C to 125°C Coating Molded Plastic Meets UL94 V-0 Requirement Solvent Resistance MIL STD 202, Method 215 Moisture Sensitivity Level 1, J-STD-020 (V115SM7 to V510SM7) © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16 Metal-Oxide Varistors (MOVs) Surface Mount Varistors > SM7 Series Tape & Reel Specifications for V50SM7 amd V60SM7 Carrier Tape P0 mm P1 W E D0 P2 B 5° 3.60 D1 B B0 W A T A0 11.30 15° 3.8 - 4.0mm K0 2 B-B A-A Plastic Reel 0.40±0.05 11.80±0.10 B0 8.60±0.10 K0 4.80±0.10 E 1.75±0.10 0. ± 13 Ø 2±0.5 2 ±0.8 Ø21 Ø330 F 7.50±0.10 P0 4.00±0.10 P1 16.00±0.10 P2 2.00±0.10 D0 ø1.50 +0.10/-0 D1 ø1.50 +0.10/-0 NOTES: 1) All dimensions per EIA-481-c 2) 10 pitches cumulative tolerance on tape ±0.20mm 3) Quantity per 13 inch (330 mm) reel: 600 pcs DETAIL H Ø100 T A0 F A 16.00±0.30 R1 16.5 120° 21.5±0.4 DETAIL H Tape & Reel Specifications for V115SM7 to V510SM7 mm E T 0.40±0.05 A0 11.80±0.10 B0 8.60±0.10 K0 6.80±0.10 E 1.75±0.10 D1 B 3.60 W A 5° B B0 D0 16.00±0.30 P1 P2 A W F Carrier Tape P0 T A0 11.30 ° 10 5° 6.2 K0 2 B-B A-A Plastic Reel DETAIL H ±0.8 Ø21 Ø330 Ø100 2 0. ± 13 Ø 2±0.5 R1 16.5 120° DETAIL H © 2016 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 04/19/16 21.5±0.4 F 7.50±0.10 P0 4.00±0.10 P1 16.00±0.10 P2 2.00±0.10 D0 ø1.50 +0.10/-0 D1 ø1.50 +0.10/-0 NOTES: 1) All dimensions per EIA-481-c 2) 10 pitches cumulative tolerance on tape ±0.20mm 3) Quantity per 13 inch (330 mm) reel: 600 pcs