LTO 50 Vishay Sfernice Power Resistor Thick Film Technology features • 50 Watt at 25 °C Case Temperature Heatsink Mounted RoHS COMPLIANT • Direct mounting ceramic on heatsink • Broad Resistance Range: R010 to 550K • Non Inductive • TO-220 package: Compact and easy to mount LTO series are the extension of RTO types. We used the direct ceramic mounting design (no metal tab) of our RCH power resistors applied to semiconductor packages. • RoHS compliant • Isolated case dimensions in millimeters 3.2 10.4 3.2 16.2 Ø3.2 1.3 3.5 12.7 0.8 0.6 1.8 5.08 • Tolerance unless otherwise specified: ± 0.3 mm mechanical specifications electrical specifications Mechanical Protection Molded Resistance Range Resistive Element Thick Film Tolerances (Standard) ± 1 % to ± 10 % Substrate Alumina Dissipation and Associated Onto a heatsink Connections Tinned Copper Weight 2 g max. Power Rating and Thermal Resistance of the component Mounting Torque 1 N-m 50 W at + 25 °C (case temperature) RTH (j-c): 2.5 °C/W free air: 2.5 W at + 25 °C Temperature Coefficient See Performance table dimensions Standard Package 0.010 Ω to 550 kΩ Standard TO-220 Isolated case Limiting Element Voltage Dielectric Strength MIL STD 202 ± 150 ppm/°C 250 V 1500 VRMS - 1 minute - 10 mA max. environmental specifications Insulation Resistance ≥ 104 MΩ Temperature Range - 55 °C to + 150 °C Inductance ≤ 0.1 μH Climatic Category 55/155/56 Critical Resistance 1.25 kΩ www.vishay.com 14 For technical questions, contact [email protected] Document Number: 50050 Revision 26-Mar-07 LTO 50 Power Resistor Thick Film Technology Vishay Sfernice performance TESTS CONDITIONS TYPICAL DRIFTS EN60115-1 1.5 Pr/5 s Us < 1.5 UL ± (0.5 % + 0.005 Ω) Momentary Overload EN60115-1 IEC 60068-2-14 Tests Na 5 cycles - 55 °C to + 155 °C ± (0.5 % + 0.005 Ω) EN60115-1 1000 h Pr at + 25 °C ± (1 % + 0.005 Ω) MIL STD 202 Method 103 B Cond. D ± (0.5 % + 0.005 Ω) Vibration MIL STD 202 Method 204 Cond. D ± (0.2 % + 0.005 Ω) Terminal Strength MIL STD 202 Method 211 Cond. A1 ± (0.2 % + 0.005 Ω) 100G, MIL STD 202 Method 213 Cond. I ± (0.5 % + 0.005 Ω) Rapid Temperature Change Load Life Humidity (Steady State) Shock special features ≥ 0.010 Resistance Values ≥ 0.015 Tolerances Typical Temperature Coefficient (- 55 °C/+ 150 °C) ≥ 0.1 ≥ 0.5 ± 250 ppm/°C ± 150 ppm/°C ± 1 % at ± 10 % ± 900 ppm/°C ± 700 ppm/°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 150 °C. The dissipated power is simply calculated by the following ratio: P= ∆T (1) [RTH (j-c) + RTH (c-a)] P: expressed in W ∆T: difference between maximum working temperature and room temperature. RTH: (j-c): thermal resistance value measured between resistive layer and outer side of the resistor. It is the thermal resistance of the component. RTH: (c-a): thermal resistance value measured between outer side of the resistor and room temperature. It is the thermal resistance of the heatsink itself (type, shape), the quality of the fastening device, and the thermal resistance of the thermal compound. Example: RTH: (c-a) for LTO50 power rating 10 W at ambient temperature + 25 °C. Thermal resistance RTH (j-c): 2.5 °C/W Considering equation (1) we have: ∆T = 150 °C - 25 °C = 125 °C 125 ∆T RTH (j-c) + RTH (c-a) = = = 12.5 °C/W 10 P RTH (c-a) = 12.5 °C/W - 2.5 °C/W = 10 °C/W with a thermal grease RTH (c - h) = 1 °C/W, we need a heat sink with RTH (h - a) = 9 °C/W. Document Number: 50050 Revision 26-Mar-07 For technical questions, contact [email protected] www.vishay.com 15 LTO 50 Vishay Sfernice Power Resistor Thick Film Technology overloads In any case the applied voltage must be lower than the maximum overload voltage of 375V. The values indicated on the graph below are applicable to resistors in air or mounted onto a heatsink. ENERGY IN JOULES enerGY curve 10 1 0.1 0.01 10 -6 10 -5 10-4 10 -3 10 -2 OVERLOAD DURATION IN SECONDS power ratinG chart The temperature of the heatsink should be maintained within the limits specified. To improve the thermal conductivity, surfaces in contact should be coated with a silicone grease and the torque applied on the screw for tightening should be around 1 Nm. % RATED POWER 100 75 50 25 0 0 20 40 60 80 100 120 140 150 HEATSINk TEMPERATURE IN DEGREES CELSIUS marKinG Model, Style, Resistance Value (in Ω), Tolerance (in %), Manufacturing Date, VISHAY trademark pacKaGinG Tube of 50 units orderinG information LTO MODEL 50 STYLE F CONNECTIONS 100 kΩ RESISTANCE VALUE ±1% TOLERANCE xxx CUSTOM DESIGN ±1% ±2% ±5% ± 10 % Optional on request: special TCR, shape etc. TU50 PACKAGING e3 LEAD (Pb)-FREE sap part numberinG Guidelines L T MODEL O 0 5 STYLE SAP Part Number LTO050F10002FTE3 www.vishay.com 16 0 F CONNECTIONS 1 0 0 0 RESISTANCE VALUE For technical questions, contact [email protected] 2 F TOL T E 3 PACK LEAD (Pb)-FREE Document Number: 50050 Revision 26-Mar-07 Legal Disclaimer Notice Vishay Notice Specifications of the products displayed herein are subject to change without notice. Vishay Intertechnology, Inc., or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Information contained herein is intended to provide a product description only. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Vishay's terms and conditions of sale for such products, Vishay assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of Vishay products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Vishay for any damages resulting from such improper use or sale. Document Number: 91000 Revision: 08-Apr-05 www.vishay.com 1