MLE Varistor Series. Features. Size Metric EIA Applications.

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1 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 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. 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-6-4-2) Characterized for Impedance and Capacitance -55 o C to +125 o C perating Temperature Range Leadless 42, 6, 85, and 126 sizes perating Voltages up to 18V M(DC) Multilayer Ceramic Construction Technology Applications Protection of Components and Circuits Sensitive to ESD Transients ccurring on Power Supplies, Control and Signal Lines Suppression of ESD Events Such as Specified in IEC or MIL-STD-88C Method-15.7, 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/ Interfaces Size Metric EIA

2 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 (V M(DC) ) perating Ambient Temperature Range (T A ) to Storage Temperature Range (T STG ) to + 15 UNITS V C C Device Ratings and Specifications NEW PART NUMBER MAX CNTINUUS WRKING VLTAGE -55 o C T 125 o C (NTE 1) V M(DC) PERFRMANCE SPECIFICATINS (25 o C) CLAMPING NMINAL VLTAGE VLTAGE AT SPECIFIED CURRENT (8/2µS) ESD CLAMP VLTAGE (NTE 2) TYPICAL LEAKAGE V NM AT (NTE ) (NTE 4) CAPACITANCE AT APPLIED 1mA DC Vc 8kV CNTACT 15kV AIR AT 1MHz I L MAX VLTAGE MIN MAX V18MLE at 1A V18MLE at 2A V18MLE6L at 1A V18MLE at 5A V18MLE85L at 2A V18MLE at 1A Clamp <125 NTES: 1. For applications of 18V DC or less. Higher voltages available, contact your Littelfuse Sales Representative. 2. Tested with IEC Human Body Model (HBM) discharge test circuit.. 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. <75 < <7 <75 <65 Clamp ( pf) ( µa) V DC <16 < <85 <14 <75 <15 <65 < < < < <

3 Typical Performance Curves For applications exceeding 125 C ambient temperature, the peak surge current and energy ratings must be reduced as shown in Figure 1. PERCENT F RATED VALUE AMBIENT TEMPERATURE ( o C) FIGURE 1. PEAK CURRENT AND ENERGY DERATING CURVE NMINAL VLTAGE AT 1mADC CURRENT (A) FIGURE 2. NMINAL VLTAGE STABILITY T MULTIPLE ESD IMPULSES (8KV CNTACT DISCHARGES PER IEC 6-4-2) 1.2 NRMALIZED VARISTR VLTAGE CURRENT (ma) FIGURE. STANDBY CURRENT AT NRMALIZED VARISTR VLTAGE AND TEMPERATURE IMPEDANCE (Z) FREQUENCY (MHz) FIGURE 4. IMPEDANCE (Z) vs FREQUENCY TYPICAL CHARACTERISTIC 11

4 Soldering Recommendations 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. The recommended solder for the MLE suppressor is a 62/6/2 (Sn/Pb/Ag), 6/4 (Sn/Pb), or 6/7 (Sn/Pb). Littelfuse also recommends an RMA solder flux. 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 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 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. nce the soldering process has been completed, it is still necessary to ensure that any further thermal shocks are avoided. ne 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 5 o C before cleaning. Termination ptions Littelfuse offers three types of electrode termination finish for the MLE series: 1. Silver/Platinum 2. Silver/Palladium. Nickel Barrier (available for package size) (The ordering information section describes how to designate them.) TEMPERATURE ( o C) TEMPERATURE ( o C) TEMPERATURE 222 o C PREHEAT DWELL PREHEAT ZNE WAVE 26 o C FIRST PREHEAT RAMP RATE <2 o C/s TIME (MINUTES) FIGURE 5. REFLW SLDER PRFILE SECND PREHEAT TIME (MINUTES) 4-8 SECNDS ABVE 18 o C FIGURE 6. WAVE SLDER PRFILE TEMPERATURE ( o C) RAMP RATE >5 o C/s TEMPERATURE 222 o C 4-8 SECNDS ABVE 18 o C PREHEAT ZNE TIME (MINUTES) FIGURE 7. VAPR PHASE SLDER PRFILE 12

5 Recommended Pad utline C B NTE A NTE: Avoid metal runs in this area. TABLE 1: PAD LAYUT DIMENSINS RECMMENDED PAD SIZE DIMENSINS 126 SIZE DEVICE 85 SIZE DEVICE 6 SIZE DEVICE 42 SIZE DEVICE DIMENSIN IN MM IN MM IN MM IN MM A B C

6 Mechanical Dimensions E D L DIMENSIN D Max W DEVICE DIMENSINS 126 SIZE 85 SIZE 6 SIZE IN MM IN MM IN MM IN SIZE MM.6 E.2±.1.5±.25.2±.1.5±.25.15±.8.4±.2.1±.6.25±.15 L.125±.12.2±..79±.8 2.1±.2.6±.6 1.6±.15.9±.4 1.±.1 W.6± ±.28.49± ±.2.2±.6.8±.15.2±.4.5±.1 rdering Information VXXMLE TYPES V 18 MLE 126 X X X DEVICE FAMILY Littelfuse TVSS Device DC WRKING VLTAGE MULTILAYER SERIES DESIGNATR PACKING PTINS A: Bulk Pack (not 42 size) H: 7in (178mm) Diameter Reel T: 1in (mm) Diameter Reel (not 42 size) END TERMINATIN PTIN No Letter: Ag/Pt W: Ag/Pd N: Nickel Barrier (42-121) DEVICE SIZE: i.e., 12 mil x 6 mil (mm x 1.5mm) CAPACITANCE PTIN No Letter: Standard L: Low Capacitance Version Standard Shipping Quantities DEVICE SIZE 1 INCH REEL ( T PTIN) 7 INCH REEL ( H PTIN) BULK PACK ( A PTIN) 126 1, 2, , 2, , 2, N/A 1, N/A 14

7 Tape and Reel Specifications Conforms to EIA , Revision A Can be supplied to IEC publication SYMBL DESCRIPTIN DIMENSINS IN MILLIMETERS 42 Size 6, 85, & 126 Sizes A Width of Cavity Dependent on Chip Size to Minimize Rotation. B Length of Cavity Dependent on Chip Size to Minimize Rotation. K Depth of Cavity Dependent on Chip Size to Minimize Rotation. W Width of Tape 8 ±.2 F Distance Between Drive Hole Centers and Cavity Centers.5 ±.5 E Distance Between Drive Hole Centers and Tape Edge 1.75 ±.1 P 1 Distance Between Cavity Centers 2±.5 4 ±.1 P 2 Axial Drive Distance Between Drive Hole Centers & Cavity Centers 2 ±.1 P Axial Drive Distance Between Drive Hole Centers 4 ±.1 D Drive Hole Diameter 1.55 ±.5 D 1 Diameter of Cavity Piercing N/A 1.5 ±.5 T 1 Top Tape Thickness.1 Max D P P 2 E K B F W t 1 D 1 P 1 A PLASTIC CARRIER TAPE EMBSSED PAPER (42 SIZE NLY) PRDUCT IDENTIFYING LABEL EMBSSMENT TP TAPE 8mm NMINAL 178mm R mm DIA. REEL 15