Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE Varistor Series The MLE Series family of Transient Voltage Suppression devices are based on the Littelfuse Multilayer fabrication technology. These components are designed to suppress ESD events, including those specified in IEC 610004-2 or other standards used for Electromagnetic Compliance testing. The MLE Series is typically applied to protect integrated circuits and other components at the circuit board level operating at 18VDC, or less. The fabrication method and materials of these devices result in capacitance characteristics suitable for high frequency attenuation/low-pass filter circuit functions, thereby providing suppression and filtering in a single device. 3 SURFACE MOUNT VARISTORS The MLE Series is manufactured from semiconducting ceramics and is supplied in a leadless, surface mount package. The MLE Series is compatible with modern reflow and wave soldering procedures. Littelfuse Inc. manufactures other Multilayer Series products. See the ML Series data sheet for higher energy/peak current transient applications. See the AUML Series for automotive applications and the MLN Quad Array. For high speed applications see the MHS series. Features • Rated for ESD (IEC-61000-4-2) • Characterized for Impedance and Capacitance •-55oC to +125oC Operating Temperature Range • Leadless 0402, 0603, 0805, and 1206 sizes • Operating Voltages up to 18VM(DC) • Multilayer Ceramic Construction Technology Applications • Protection of Components and Circuits Sensitive to ESD Transients Occurring on Power Supplies, Control and Signal Lines • Suppression of ESD Events Such as Specified in IEC-61000-4-2 or MIL-STD-883C Method-3015.7, for Electromagnetic Compliance (EMC) • Used in Mobile Communications, Computer/EDP Products, Medical Products, Hand Held/Portable Devices, Industrial Equipment, Including Diagnostic Port Protection and I/O Interfaces w w w. l i t t e l f u s e . c o m 133 Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE Varistor Series Absolute Maximum Ratings For ratings of individual members of a series, see device ratings and specifications table. Continuous: MLE SERIES Steady State Applied Voltage: DC Voltage Range (VM(DC)) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≤18 Operating Ambient Temperature Range (TA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to + 125 Storage Temperature Range (TSTG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to + 150 UNITS V C O C O Device Ratings and Specifications NEW PERFORMANCE SPECIFICATIONS (25 oC) MAX CONTINUOUS WORKING VOLTAGE -55oC TO 125oC NOMINAL VOLTAGE MAXIMUM CLAMPING VOLTAGE AT SPECIFIED CURRENT (8/20µS) (NOTE 1) VM(DC) VNOM AT 1mA DC Vc (NOTE 3) 8kV CONTACT (NOTE 4) 15kV AIR (V) Clamp (V) Clamp (V) PART NUMBER (V) MIN (V) MAX (V) V18MLE0402 18 22 28 V18MLE0603 V18MLE0603L V18MLE0805 V18MLE0805L V18MLE1206 18 18 18 18 18 22 22 22 22 22 28 28 28 28 28 50 at 10A 50 at 10A 50 at 10A 50 at 10A 50 at 10A 50 at 10A MAXIMUM ESD CLAMP VOLTAGE (NOTE 2) <125 <75 <100 <70 <75 <65 <160 <85 <140 <75 <135 <65 NOTES: 1. For applications of 18VDC or less. Higher voltages available, contact your Littelfuse Sales Representative. 2. Tested with IEC-61000-4-2 Human Body Model (HBM) discharge test circuit. 3. Direct discharge to device terminals (IEC preferred test method). 4. Corona discharge through air (represents actual ESD event). 5. Capacitance may be customized, contact your Littelfuse Sales Representative. 134 w w w. l i t t e l f u s e . c o m MAXIMUM LEAKAGE TYPICAL CAPACITANCE AT 1MHz I L MAX AT APPLIED VOLTAGE ( pF) ( µA) V DC <40 0.1 3.5 0.3 5.5 2 15 <100 <60 <500 <100 <1700 10 18 0.1 3.5 0.3 5.5 5.0 15 25 18 0.1 3.5 0.3 5.5 5.0 15 25 18 0.2 3.5 0.5 5.5 5.0 15 25 18 0.2 3.5 0.5 5.5 5.0 15 25 18 0.5 3.5 1.0 5.5 5.0 15 25 18 Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE Varistor Series Typical Performance Curves For applications exceeding 1250C ambient temperature, the peak surge current and energy ratings must be reduced as shown in Figure 1. 30 NOMINAL VOLTAGE AT 1mADC 80 60 40 20 0 -55 25 20 3 15 SURFACE MOUNT VARISTORS PERCENT OF RATED VALUE 100 10 5 0 50 60 70 80 90 100 110 120 10 1 130 140 150 100 AMBIENT TEMPERATURE ( oC) 10000 FIGURE 2. NOMINAL VOLTAGE STABILITY TO MULTIPLE ESD IMPULSES (8KV CONTACT DISCHARGES PER IEC 61000-4-2) FIGURE 1. PEAK CURRENT AND ENERGY DERATING CURVE 100 30 25 -0402 -0603 10 20 25O 15 -0805 IMPEDANCE (Z) VARISTOR VOLTAGE (V) 1000 CURRENT (A) 85O 10 125O 5 -1206 1 0.1 10 0.0001 0.001 0.01 0.1 1 NUMBER OF PULSES FIGURE 3. STANDBY CURRENT AT NORMALIZED VARISTOR VOLTAGE AND TEMPERATURE 0.01 10 100 1000 10000 FREQUENCY (MHz) FIGURE 4. IMPEDANCE (Z) vs FREQUENCY TYPICAL CHARACTERISTIC w w w. l i t t e l f u s e . c o m 135 Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE Varistor Series Soldering Recommendations 250 The recommended solder for the MLE 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. MAXIMUM TEMPERATURE 222 oC 200 TEMPERATURE ( oC) The principal techniques used for the soldering of components in surface mount technology are Infrared (IR) re-flow, vapour phase re-flow, and wave soldering. When wave soldering, the MLE suppressor is attached to the circuit board by means of an adhesive. The assembly is then placed on a conveyor and run through the soldering process to contact the wave. With IR and vapour phase re-flow, the device is placed in a solder paste on the substrate. As the solder paste is heated, it reflows and solders the unit to the board. RAMP RATE <2oC/s 100 PREHEAT DWELL PREHEAT ZONE 0 0 0.5 1.0 1.5 2.0 2.5 TIME (MINUTES) 3.0 3.5 4.0 FIGURE 5. REFLOW SOLDER PROFILE 300 MAXIMUM WAVE 260 oC 250 TEMPERATURE ( oC) 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. 150 50 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. For 0402 size devices, IR re-flow is recommended. When using a reflow process, care should be taken to ensure that the MLE 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. Examples of the soldering conditions for the MLE series of suppressors are given in the tables below. 40-80 SECONDS ABOVE 183 oC 200 150 SECOND PREHEAT 100 FIRST PREHEAT 50 Termination Options Littelfuse offers two types of electrode termination finish for the MLE series: 0 0 0.5 1.0 1.5 2.0 2.5 3.0 TIME (MINUTES) 3.5 4.0 4.5 1. Silver/Platinum (standard) (Not 0402 and 0603 sizes) FIGURE 6. WAVE SOLDER PROFILE 2. Silver/Palladium (optional) 3. Nickel Barrier (optional for 0402-1210 package size) (The ordering information section describes how to designate them.) 250 MAXIMUM TEMPERATURE 222 oC TEMPERATURE ( oC) 200 40-80 SECONDS ABOVE 183 oC 150 RAMP RATE >50oC/s 100 PREHEAT ZONE 50 0 0 0.5 1.0 1.5 2.0 2.5 3.0 TIME (MINUTES) FIGURE 7. VAPOR PHASE SOLDER PROFILE 136 w w w. l i t t e l f u s e . c o m 3.5 Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE Varistor Series Recommended Pad Outline C B NOTE 3 SURFACE MOUNT VARISTORS A NOTE: Avoid metal runs in this area. TABLE 1: PAD LAYOUT DIMENSIONS RECOMMENDED PAD SIZE DIMENSIONS 1206 SIZE DEVICE 0805 SIZE DEVICE 0603 SIZE DEVICE 0402 SIZE DEVICE DIMENSION IN MM IN MM IN MM IN MM A 0.160 4.06 0.120 3.05 0.100 2.54 0.067 1.70 B 0.065 1.65 0.050 1.27 0.030 0.76 0.020 0.51 C 0.040 1.02 0.040 1.02 0.035 0.89 0.024 0.61 w w w. l i t t e l f u s e . c o m 137 Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE Varistor Series Mechanical Dimensions E D L W DEVICE DIMENSIONS 1206 SIZE 0805 SIZE 0402 SIZE 0603 SIZE DIMENSION IN MM IN MM IN MM IN D Max 0.071 1.80 0.043 1.1 0.035 0.9 0.024 MM E 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±0.03 0.079±0.008 2.01±0.2 0.063±0.006 1.6±0.15 0.039±0.004 1.0±0.1 W 0.06±0.011 1.60±0.28 0.049±0.008 1.25±0.2 0.032±0.006 0.8±0.15 0.020±0.004 0.5±0.1 0.6 Ordering Information VXXMLE TYPES V 18 MLE 1206 X X DEVICE FAMILY Littelfuse TVSS Device X PACKING OPTIONS A: Bulk Pack (not 0402 size) H: 7in (178mm) Diameter Reel T: 13in (330mm) Diameter Reel (not 0402 size) END TERMINATION OPTION No Letter: Ag/Pt (Standard) W: Ag/Pd N: Nickel Barrier (0402-1210) For 0402 package size, Nickel Barrier termination is subject to availibility. Please contact a Littelfuse sales representative. MAXIMUM DC WORKING VOLTAGE MULTILAYER SERIES DESIGNATOR DEVICE SIZE: i.e., 120 mil x 60 mil CAPACITANCE OPTION No Letter: Standard L: Low Capacitance Version (3mm x 1.5mm) Standard Shipping Quantities DEVICE SIZE 138 “13”INCH REEL (“T”OPTION) “7”INCH REEL (“H”OPTION) BULK PACK (“A”OPTION) 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 Next Previous Surface Mount Varistors Multilayer Transient Voltage Suppressor MLE 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 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 SURFACE MOUNT VARISTORS 8 ±0.2 3.5 ±0.05 1.75 ±0.1 E Distance Between Drive Hole Centers and Tape Edge 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 2±0.05 4 ±0.1 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 CARRIERTAPE EMBOSSMENT TOP TAPE 8mm NOMINAL w w w. l i t t e l f u s e . c o m 178mm OR 330mm DIA. REEL 139