LTO 100 Vishay Sfernice Power Resistor Thick Film Technology FEATURE 100 W at 25 C case temperature heatsink RoHS mounted COMPLIANT Direct mounting ceramic on heatsink Broad resistance range: R015 to 1M Non inductive TO-247 package: Compact and easy to mount LTO series are the extension of RTO types. We used the RoHS compliant direct ceramic mounting design (no metal tab) of our RCH power resistors applied to semiconductor packages. DIMENSIONS in millimeters 5.0 15.76 5.33 20.7 3.6 3.6 3.5 14.5 1.5 0.6 2.4 10.16 MECHANICAL SPECIFICATIONS ELECTRICAL SPECIFICATIONS Mechanical Protection Molded Resistance Range 0.015 to 1 M Resistive Element Thick film Tolerances (Standard) 1 % to 10 % Substrate Alumina Dissipation and Associated Onto a heatsink Connections Tinned copper Weight 3.5 g max. 100 W at + 25 C (case temp.) Power Rating and R (j - c): 1.5 C/W Mounting Torqure 1 Nm TH Thermal Resistance Free air: of the Component 3.5 W at + 25 C DIMENSIONS Temperature Coefficient See Performance table Standard Package TO-247 isolated case Standard 150 ppm/C ENVIRONMENTAL SPECIFICATIONS Limiting Element Voltage U 375 V L Dielectric Strength 1500 V - 1 min RMS Temperature Range - 55 C to + 175 C MIL STD 202 10 mA max. Climatic Category 55/175/56 4 Insulation Resistance 10 M Flammability IEC 60695-11-5 2 applications 30 s Inductance 0.1 H separated by 60 s Critical Resistance 1.41 k Document Number: 50051 For technical questions, contact: sfer vishay.com www.vishay.com Revision: 16-Oct-08 1LTO 100 Power Resistor Thick Film Technology Vishay Sfernice PERFORMANCE TESTS CONDITIONS REQUIREMENTS EN 60115-1 Momentary Overload 1.5 Pr/5 s (0.5 % + 0.005 ) U < 1.5 U S L EN 60115-1 IEC 60068-2-14 Tests Na Rapid Temperature Change (0.5 % + 0.005 ) 5 cycles - 55 C to + 175 C EN 60115-1 Load Life (1 % + 0.005 ) 1000 h Pr at + 25 C MIL STD 202 Humidity (Steady State) (0.5 % + 0.005 ) Method 103 B Cond. D MIL STD 202 Vibration (0.2 % + 0.005 ) Method 204 Cond. D MIL STD 202 Terminal Strength (0.2 % + 0.005 ) Method 211 Cond. A1 100G, MIL STD 202 Shock (0.5 % + 0.005 ) Method 213 Cond. I SPECIAL FEATURES Resistance Values 0.010 0.015 0.1 0.5 Tolerances 1 % at 10 % Typical Temperature Coefficient 900 ppm/C 700 ppm/C 250 ppm/C 150 ppm/C (- 55 to + 175 C) CHOICE OF THE HEATSINK The user must choose according to the working conditions of the component (power, room temperature). Maximum working temperature must not exceed 175 C. The dissipated power is simply calculated by the following ratio: ()1 T ---------------------------------------------------------------------- P = R jc() + R ()ca TH TH P: Expressed in W T: Difference between maximum working temperature and room temperature R (j - c): Thermal resistance value measured between resistive layer and outer side of the resistor. It is the thermal TH resistance of the component. R (c - a): Thermal resistance value measured between outer side of the resistor and room temperature. It is the thermal TH resistance of the heatsink itself (type, shape) and the quality of the fastening device, and the thermal resistance of the thermal compound. Example: R (c - a) for LTO 100 power rating 10 W at ambient temperature + 25 C TH Thermal resistance R (j - c): 1.5 C/W TH Considering equation (1) we have: T = 175 C - 25 C = 150 C T 150 ------- ---------- R (j - c) + R (c - a) = = = 15 C/W TH TH P 10 R (c - a) = 15 C/W - 1.5 C/W = 13.5 C/W TH with a thermal grease R (c - h) = 1 C/W, we need a heatsink with R (h - a) = 12.5 C/W. TH TH www.vishay.com For technical questions, contact: sfer vishay.com Document Number: 50051 2 Revision: 16-Oct-08