Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series The ML Series family of Transient Voltage Surge Suppression devices is based on the Littelfuse Multilayer fabrication technology. These components are designed to suppress a variety of transient events, including those specified in IEC 61000-4-2 or other standards used for Electromagnetic Compliance (EMC). The ML Series is typically applied to protect integrated circuits and other components at the circuit board level. The wide operating voltage and energy range make the ML Series suitable for numerous applications on power supply, control and signal lines. The ML Series is manufactured from semiconducting ceramics, and is supplied in a leadless, surface mount package. The ML Series is compatible with modern reflow and wave soldering procedures. It can operate over a wider temperature range than zener diodes, and has a much smaller footprint than plastic-housed components. Littelfuse Inc. manufactures other Multilayer Series products. See the MLE Series data sheet for ESD applications, MHS Series data sheet for high-speed ESD applications, the MLN for multiline protection and the AUML Series for automotive applications. Features • RoHS Compliant Size • Leadless 0402, 0603, 0805, 1206 and 1210 Chip Sizes • Multilayer Ceramic Construction Technology •-55oC to +125oC Operating Temperature Range • Operating Voltage Range VM(DC) = 5.5V to 120V • Rated for Surge Current (8 x 20µs) • Rated for Energy (10 x 1000µs) • Inherent Bi-directional Clamping • No Plastic or Epoxy Packaging Assures Better than 94V-0 Flammability Rating • Standard Low Capacitance Types Available Applications • Suppression of Inductive Switching or Other Transient Events Such as EFT and Surge Voltage at the Circuit Board Level • ESD Protection for Components Sensitive to IEC 61000-4-2, MIL-STD-883C Method 3015.7, and Other Industry Specifications (See Also the MLE or MLN Series) • Provides On-Board Transient Voltage Protection for ICs and Transistors • Used to Help Achieve Electromagnetic Compliance of End Products • Replace Larger Surface Mount TVS Zeners in Many Applications 168 w w w. l i t t e l f u s e . c o m Metric EIA 1005 1608 2012 3216 3225 4532 5650 0402 0603 0805 1206 1210 1812 2220 Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Absolute Maximum Ratings For ratings of individual members of a series, see Device Ratings and Specifications table. Continuous: ML SERIES Steady State Applied Voltage: DC Voltage Range (VM(DC)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 to 120 AC Voltage Range (VM(AC)RMS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 to 107 Transient: Non-Repetitive Surge Current, 8/20µs Waveform, (ITM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 to 500 Non-Repetitive Surge Energy, 10/1000µs Waveform, (WTM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.02 to 1.2 Operating Ambient Temperature Range (TA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to + 125 Storage Temperature Range (TSTG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to + 150 Temperature Coefficient ( V) of Clamping Voltage (VC) at Specified Test Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <0.01 Device Ratings and Specifications MAXIMUM RATINGS (125 oC) 170 SPECIFICATIONS (25 oC) MAXIMUM CONTINUOUS WORKING VOLTAGE MAXIMUM NONREPETITIVE SURGE CURRENT (8/20 s) MAXIMUM NONREPETITIVE SURGE ENERGY (10/1000 s) MAXIMUM CLAMPING VOLTAGE AT 1A (OR AS NOTED) (8/20 s) VN(DC) VN(DC) VM(DC) VM(AC) ITM WTM VC MIN MAX C NOMINAL VOLTAGE AT 1mA DC TEST CURRENT TYPICAL CAPACITANCE AT f = 1MHz PART NUMBER (V) (V) (A) (J) (V) (V) (V) (pF) V3.5MLA0603 3.5 2.5 30 0.1 13 3.7 7.0 1270 V3.5MLA0805 3.5 2.5 120 0.3 13 3.7 7.0 2530 V3.5MLA0805L 3.5 2.5 40 0.1 13 3.7 7.0 1380 V3.5MLA1206 3.5 2.5 100 0.3 13 3.7 7.0 6000 V5.5MLA0402 5.5 4.0 20 0.050 19 7.1 10.8 220 V5.5MLA0402L 5.5 4.0 20 0.050 38 15.9 21.5 70 V5.5MLA0603 5.5 4.0 30 0.1 17.5 7.1 9.3 760 V5.5MLA0805 5.5 4.0 120 0.3 17.5 7.1 9.3 1840 V5.5MLA0805L 5.5 4.0 40 0.1 17.5 7.1 9.3 990 V5.5MLA1206 5.5 4.0 150 0.4 17.5 7.1 9.3 3500 V9MLA0402 9 6.5 20 0.050 30 11 16 120 V9MLA0402L 9 6.5 4 0.020 35 11 16 33 V9MLA0603 9.0 6.5 30 0.1 25.5 11 16 490 V9MLA0805L 9.0 6.5 40 0.1 25.5 11 16 520 V12MLA0805L 12 9.0 40 0.1 29 14 18.5 410 V14MLA0402 14 10 20 0.050 38 15.9 21.5 70 V14MLA0603 14 10 30 0.1 34.5 15.9 21.5 180 V14MLA0805 14 10 120 0.3 32 15.9 20.3 560 V14MLA0805L 14 10 40 0.1 32 15.9 20.3 320 V14MLA1206 14 10 150 0.4 32 15.9 20.3 1400 w w w. l i t t e l f u s e . c o m UNITS V V A J O C O C %/OC Multilayer Transient Voltage Surge Suppressors ML Varistor Series Device Ratings and Specifications (Continued) MAXIMUM RATINGS (125 oC) PART NUMBER SPECIFICATIONS (25 oC) MAXIMUM CONTINUOUS WORKING VOLTAGE MAXIMUM NONREPETITIVE SURGE CURRENT (8/20 s) MAXIMUM NONREPETITIVE SURGE ENERGY (10/1000 s) MAXIMUM CLAMPING VOLTAGE AT 1A (OR AS NOTED) (8/20 s) VN(DC) VN(DC) VM(DC) VM(AC) ITM WTM VC MIN MAX C NOMINAL VOLTAGE AT 1mA DC TEST CURRENT TYPICAL CAPACITANCE AT f = 1MHz (V) (V) (A) (J) (V) (V) (V) (pF) V18MLA0402 18 14 20 0.050 50 22 28.0 40 V18MLA0603 18 14 30 0.1 50 22 28.0 120 V18MLA0805 18 14 120 0.3 44 22 28.0 520 V18MLA0805L 18 14 40 0.1 44 22 28.0 290 V18MLA1206 18 14 150 0.4 44 22 28.0 1270 V18MLA1210 18 14 500 2.5 22 28.0 1440 V26MLA0603 26 20 30 0.1 60 31 38 110 V26MLA0805 26 20 100 0.3 60 29.5 38.5 220 V26MLA0805L 26 20 40 0.1 60 29.5 38.5 140 V26MLA1206 26 20 150 0.6 60 29.5 38.5 600 V26MLA1210 26 20 300 1.2 29.5 38.5 1040 V30MLA0603 30 25 30 0.1 74 37 46 90 V30MLA0805L 30 25 30 0.1 72 37 46 90 V30MLA1210 30 25 280 1.2 68 at 2.5A 35 43 1820 V30MLA1210L 30 25 220 0.9 68 at 2.5A 35 43 1760 V33MLA1206 33 26 180 0.8 75 38 49 500 V42MLA1206 42 30 180 0.8 92 46 60 425 V48MLA1210 48 40 250 1.2 105 at 2.5A 54.5 66.5 520 V48MLA1210L 48 40 220 0.9 105 at 2.5A 54.5 66.5 500 V56MLA1206 56 40 180 1.0 61 77 180 V60MLA1210 60 50 250 1.5 67 83 440 V68MLA1206 68 50 180 1.0 76 90 100 V85MLA1210 85 67 250 2.5 180 at 2.5A 95 115 260 V120MLA1210 120 107 125 2.0 260 at 2.5A 135 165 80 44 at 2.5A 60 at 2.5A 120 130 at 2.5A 140 3 SURFACE MOUNT VARISTORS RoHS NOTES: 1. L suffix is a low capacitance and energy version; Contact your Littelfuse Sales Representative for custom capacitance requirements. o 2. Typical leakage at 25 C<25µA, maximum leakage 100µA at VM(DC) ; for 0402 size, typical leakage <5µA, maximum leakage <20µA at VM(DC). 3. Average power dissipation of transients for 0402, 0603, 0805, 1206 and 1210 sizes not to exceed 0.03W, 0.05W, 0.1W, 0.1W and 0.15W respectively. w w w. l i t t e l f u s e . c o m 171 Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors ML Varistor Series Temperature De-rating PERCENT OF PEAK VALUE 100 50 0 t O1 100 TIME t1 80 t2 60 FIGURE 2. PEAK PULSE CURRENT TEST WAVEFORM FOR CLAMPING VOLTAGE 40 20 0 -55 50 60 70 80 90 100 110 120 O1 = VIRTUAL ORIGIN OF WAVE t = TIME FROM 10% TO 90% OF PEAK t1 = VIRTUAL FRONT TIME = 1.25 x t t2 = VIRTUAL TIME TO HALF VALUE (IMPULSE DURATION) 130 140 150 AMBIENT TEMPERATURE ( oC) FIGURE 1. PEAK CURRENT AND ENERGY DERATING CURVE EXAMPLE: FOR AN 8/20µs CURRENT WAVEFORM 8µs = t1 = VIRTUAL FRONT TIME 3 20µs = t2 = VIRTUAL TIME TO HALF VALUE MLA0402 Limit VI Curves 100 Varistor Voltage (V) PERCENT OF RATED VALUE When transients occur in rapid succession, the average power dissipation is the energy (watt-seconds) per pulse times the number of pulses per second. The power so developed must be within the specifications shown on the Device Ratings and Specifications table for the specific device. For applications exceeding 125oC ambient temperature, the peak surge current and energy ratings must be derated as shown in Figure 1. SURFACE MOUNT VARISTORS RoHS 10 V18MLA0402 V14MLA0402 V9MLA0402 V5.5MLA0402 1 0.000001 0.00001 0.0001 0.001 0.01 0.1 1 10 100 Current (A) FIGURE 3. LIMIT V-I CHARACTERISTIC FOR V5.5MLA0402 TO V18MLA0402 w w w. l i t t e l f u s e . c o m 171 Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Maximum Transient V-I Characteristic Curves MLA0402L Limit VI Curves Varistor Voltage (V) 100 10 V9MLA0402L V5.5MLA0402L 1 0.000001 0.00001 0.0001 0.001 0.01 0.1 1 10 100 Current (A) FIGURE 4. LIMIT V-I CHARACTERISTIC FOR V9MLA0402L 1000 V30MLA0603 V26MLA0603 Varistor Voltage (V) V18MLA0603 100 V14MLA0603 10 V9MLA0603 V5.5MLA0603 V3.5MLA0603 1 0.00001 0.0001 0.001 0.01 0.1 1 10 100 Current (A) FIGURE 5. LIMIT V-I CHARACTERISTIC FOR V3.5MLA0603 TO V30MLA0603 1000 V30MLA0805L V26MLA0805L Varistor Voltage (V) V18MLA0805L 100 V14MLA0805L 10 V12MLA0805L V9MLA0805L V5.5MLA0805L V3.5MLA0805L 1 0.00001 0.0001 0.001 0.01 0.1 1 10 Current (A) FIGURE 6. LIMIT V-I CHARACTERISTIC FOR V3.5MLA0805L TO V30MLA0805L 172 w w w. l i t t e l f u s e . c o m 100 Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors ML Varistor Series Maximum Transient V-I Characteristic Curves (Continued) Varistor Voltage (V) 1000 100 V26MLA0805 10 V18MLA0805 V14MLA0805 V5.5MLA0805 3 V3.5MLA0805 1 0.00001 0.0001 0.001 0.01 0.1 1 10 100 SURFACE MOUNT VARISTORS RoHS 1000 Current (A) FIGURE 7. LIMIT V-I CHARACTERISTIC FOR V3.5MLA0805 TO V26MLA0805 1000 Varistor Voltage (V) 100 V68MLA1206 V56MLA1206 V42MLA1206 V33MLA1206 V26MLA1206 V18MLA1206 V14MLA1206 V5.5MLA1206 V3.5MLA1206 10 1 0.00001 0.0001 0.001 0.01 0.1 1 10 100 1000 Current (A) FIGURE 6. LIMIT V-1 CHARACTERISTIC FOR V3.5MLA1206 TO V68MLA1206 1000 MAXIMUM CLAMPING VOLTAGE MAXIMUM LEAKAGE 100 Varistor Voltage (V) V120MLA1210 10 V85MLA1210 V60MLA1210 V48MLA1210, V48MLA1210L V30MLA1210, V30MLA1210L V26MLA1210 V18MLA1210 1 1 µA 10µA 100µA 1mA 10mA 100mA 1A 10A 100A 1000A CURRENT (A) FIGURE 9. LIMIT V-I CHARACTERISTIC FOR V18MLA1210 TO V120MLA1210 w w w. l i t t e l f u s e . c o m 173 Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Device Characteristics 100 CLAMPING VOLTAGE (V) At low current levels, the V-I curve of the multilayer transient voltage suppressor approaches a linear (ohmic) relationship and shows a temperature dependent effect (Figure 10). At or below the maximum working voltage, the suppressor is in a high resistance mode (approaching 106Ω at its maximum rated working voltage). Leakage currents at maximum rated voltage are below 50µA, typically 25µA; for 0402 size below 10µA, typically 5µA. V5.5MLA1206 VNOM VALUE AT 25 oC (%) SUPPRESSOR VOLTAGE IN PERCENT OF 100% V26MLA1206 10 -60 -40 -20 0 40 60 80 20 TEMPERATURE ( oC) 100 120 140 FIGURE 12. CLAMPING VOLTAGE OVER TEMPERATURE (VC AT 10A) 25 10% 1E -9 o 50o 75o 1E -8 1E -7 Energy Absorption/Peak Current Capability 100o 125oC 1E -6 1E -5 1E -4 1E -3 1E -2 SUPPRESSOR CURRENT (ADC) FIGURE 10. TYPICAL TEMPERATURE DEPENDANCE OF THE CHARACTERISTIC CURVE IN THE LEAKAGE REGION Speed of Response The Multilayer Suppressor is a leadless device. Its response time is not limited by the parasitic lead inductances found in other surface mount packages. The response time of the Zinc Oxide dielectric material is less than 1 nanosecond and the ML can clamp very fast dV/dT events such as ESD. Additionally, in “real world” applications, the associated circuit wiring is often the greatest factor effecting speed of response. Therefore, transient suppressor placement within a circuit can be considered important in certain instances. Energy dissipated within the ML is calculated by multiplying the clamping voltage, transient current and transient duration. An important advantage of the multilayer is its interdigitated electrode construction within the mass of dielectric material. This results in excellent current distribution and the peak temperature per energy absorbed is very low. The matrix of semiconducting grains combine to absorb and distribute transient energy (heat) (Figure 11). This dramatically reduces peak temperature; thermal stresses and enhances device reliability. As a measure of the device capability in energy and peak current handling, the V26MLA1206A part was tested with multiple pulses at its peak current rating (150A, 8/20µs). At the end of the test, 10,000 pulses later, the device voltage characteristics are still well within specification (Figure 13). 100 PEAK CURRENT = 150A 8/20µs DURATION, 30s BETWEEN PULSES FIRED CERAMIC DIELECTRIC VOLTAGE V26MLA1206 METAL ELECTRODES 10 METAL END TERMINATION 0 2000 4000 6000 8000 NUMBER OF PULSES FIGURE 13. REPETITIVE PULSE CAPABILITY DEPLETION REGION DEPLETION REGION GRAINS FIGURE 11. MULTILAYER INTERNAL CONSTRUCTION 174 w w w. l i t t e l f u s e . c o m 10000 12000 Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Soldering Recommendations 230 Lead (Pb) Soldering Recommendations The principal techniques used for the soldering of components in surface mount technology are IR Re-flow & Wave soldering. Typical profiles are shown in Figures 14 & 15 The termination options available for each solder technique are: Reflow 1. Nickel Barrier (preferred) 2. Silver/Platinum Wave 1. Nickel Barrier (preferred) 2. Silver/Palladium The recommended solder for the ML suppressor is a 62/36/2 (Sn/Pb/Ag), 60/40 (Sn/Pb) or 63/37 (Sn/Pb). Littelfuse also recommends an RMA solder flux. FIGURE 14. REFLOW SOLDER PROFILE 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. 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 50˚C before cleaning. MAXIMUM WAVE 260 oC 250 TEMPERATURE ( oC) When using a reflow process, care should be taken to ensure that the ML 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 solderís peak temperature is essential to minimize thermal shock. 300 200 150 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 FIGURE 15. WAVE SOLDER PROFILE Lead-Free (Pb-free) Soldering Recommendations Littelfuse offers the Nickel-Barrier termination finish for the optimum Pbfree solder performance. MAXIMUM TEMPERATURE 260˚C 20 - 40 SECONDS WITHIN 5˚C RAMP RATE <3˚C/s The preferred solder is 96.5/3.0/0.5 (SnAgCu) with an RMA flux, but there is a wide selection of pastes & fluxes available with which the nickel barrier parts should be compatible. The reflow profile must be constrained by maximums shown in Figure16. For Pb-free Wave soldering, Figure 15 still applies. Note: the Pb-free paste, flux & profile were used for evaluation purposes by Littelfuse, based upon industry standards & 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. 176 w w w. l i t t e l f u s e . c o m 60 - 150 SEC > 217˚C PREHEAT ZONE 5.0 6.0 7.0 FIGURE 16. LEAD-FREE RE-FLOW SOLDER PROFILE Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Recommended Pad Outline C B NOTE A NOTE: Avoid metal runs in this area. TABLE 1: PAD LAYOUT DIMENSIONS PAD SIZE 1210 SIZE DEVICE 1206 SIZE DEVICE 0805 SIZE DEVICE 0603 SIZE DEVICE MM IN MM 0.100 2.54 0.067 1.70 0.030 0.76 0.020 0.51 0.89 0.024 0.61 DIMENSION IN MM IN MM IN MM A 0.160 4.06 0.160 4.06 0.120 3.05 B 0.100 2.54 0.065 1.65 0.050 1.27 C 0.040 1.02 0.040 1.02 0.040 1.02 0.035 176 w w w. l i t t e l f u s e . c o m 0402 SIZE DEVICE IN Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Mechanical Dimensions 3 D SURFACE MOUNT VARISTORS E L W CHIP SIZE 1210 1206 0805 0603 0402 DIMENSION IN MM IN MM IN MM IN MM IN D Max. 0.113 2.87 0.071 1.80 0.043 1.10 0.035 0.90 0.024 0.90 E 0.02 ±0.01 0.50 ±0.25 0.02 ±0.01 0.50 ±0.25 0.02 ± 0.01 0.50 ± 0.25 0.015 ±0.008 0.4 ±0.2 0.010 ±0.006 0.25 ±0.15 L 0.125 ±0.012 3.20 ±0.30 0.125 ±0.012 3.20 ±0.30 0.079 ±0.008 2.01 ±0.20 0.063 ±0.006 1.6 ±0.15 0.039 ±0.004 1.0 ±0.1 W 0.10 ±0.012 2.54 ±0.30 0.06 ±0.011 1.60 ±0.28 0.049 ±0.008 1.25 ±0.20 0.032 ±0.06 0.8 ±0.15 0.020 ±0.004 0.5 ±0.1 MM Ordering Information VXXML TYPES V 18 MLA 1206 X X X DEVICE FAMILY Littelfuse TVSS Device PACKING OPTIONS T: 13in (330mm) Diameter Reel H: 7in (178mm) Diameter Reel (0603-1210 sizes) R: 7in (178mm) Diameter Reel (0402 size only) A: Bulk Pack MAXIMUM DC WORKING VOLTAGE END TERMINATION OPTION No Letter: Ag/Pt W: Ag/Pd N: Nickel Barrier (0402 -1210 only). MULTILAYER SERIES DESIGNATOR DEVICE SIZE: i.e 120 mil x 60 mil (3MM X 1.5MM) CAPACITANCE OPTION No Letter: Standard L: Low Capacitance Version Standard Shipping Quantities DEVICE SIZE “13” INCH REEL (“T”OPTION) “7”INCH REEL (“H”OPTION) 1210 8,000 2,000 2500 1206 10,000 2,500 2500 0805 10,000 2,500 2500 0603 10,000 2,500 2500 0402 N/A 10,000 N/A w w w. l i t t e l f u s e . c o m BULK PACK (“A”OPTION) 177 Surface Mount Varistors Multilayer Transient Voltage Surge Suppressors RoHS ML Varistor Series Tape and Reel Specifications • Conforms to EIA - 481-1, Revision A • Can be supplied to IEC Publication 286 - 3 SYMBOL DIMENSIONS IN MILLIMETERS DESCRIPTION 0402 Size 0603, 0805, 1206 & 1210 Sizes A0 Width of Cavity Dependent on Chip Size to Minimize Rotation. B0 Length of Cavity Dependent on Chip Size to Minimize Rotation. K0 Depth of Cavity Dependent on Chip Size to Minimize Rotation. W Width of Tape F Distance Between Drive Hole Centers and Cavity Centers 3.5 ±0.05 E Distance Between Drive Hole Centers and Tape Edge 1.75 ±0.1 P1 Distance Between Cavity Centers P2 Axial Drive Distance Between Drive Hole Centers & Cavity Centers 2 ±0.1 P0 Axial Drive Distance Between Drive Hole Centers 4 ±0.1 D0 Drive Hole Diameter D1 Diameter of Cavity Piercing T1 Top Tape Thickness 8 ±0.2 4 ±0.1 2±0.05 1.55 ±0.05 1.05 ±0.05 N/A 0.1 Max D0 P0 P2 E F K0 W B0 t1 P1 D1 A0 PRODUCT IDENTIFYING LABEL PLASTIC CARRIER TAPE EMBOSSED PAPER (0402 SIZE ONLY) EMBOSSMENT TOP TAPE 178 8mm NOMINAL w w w. l i t t e l f u s e . c o m 178mm OR 330mm DIA. REEL