LTO 50 Vishay Sfernice Power Resistor Thick Film Technology FEATURE • 50 W 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 Ø 3.2 1.3 3.5 12.7 0.8 0.6 5.08 MECHANICAL SPECIFICATIONS Mechanical Protection Resistive Element Substrate Connections Weight Mounting Torqure Molded Thick film Alumina Tinned copper 2 g max. 1 Nm DIMENSIONS Standard Package TO-220 isolated case 1.8 ELECTRICAL SPECIFICATIONS 0.010 Ω to 550 kΩ Resistance Range Tolerances (Standard) Dissipation and Associated Power Rating and Thermal Resistance of the Component Temperature Coefficient Standard ENVIRONMENTAL SPECIFICATIONS Limiting Element Voltage UL Temperature Range Climatic Category Flammability Dielectric Strength MIL STD 202 Document Number: 50050 Revision: 16-Oct-08 - 55 °C to + 155 °C 55/155/56 IEC 60695-11-5 2 applications 30 s separated by 60 s ± 1 % to ± 10 % Onto a heatsink 50 W at + 25 °C (case temp.) RTH (j - c): 2.5 °C/W Free air: 2.5 W at + 25 °C See Performance table ± 150 ppm/°C 250 V 1500 VRMS - 1 min 10 mA max. Insulation Resistance ≥ 104 MΩ Inductance ≤ 0.1 µH Critical Resistance 1.25 kΩ For technical questions, contact: [email protected] www.vishay.com 1 LTO 50 Vishay Sfernice Power Resistor Thick Film Technology PERFORMANCE TESTS CONDITIONS REQUIREMENTS EN 60115-1 1.5 Pr/5 s US < 1.5 UL ± (0.5 % + 0.005 Ω) EN 60115-1 IEC 60068-2-14 Tests Na 5 cycles - 55 °C to + 155 °C ± (0.5 % + 0.005 Ω) EN 60115-1 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) Momentary Overload Rapid Temperature Change Load Life Humidity (Steady State) Shock SPECIAL FEATURES ≥ 0.010 Resistance Values ≥ 0.015 Tolerances ≥ 0.1 ≥ 0.5 ± 250 ppm/°C ± 150 ppm/°C ± 1 % at ± 10 % Typical Temperature Coefficient (- 55 ° to + 155 °C) ± 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: (1) ΔT P = ---------------------------------------------------------------------[ R TH ( j – c ) + R TH ( c – a ) ] P: Expressed in W ΔT: 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) and the quality of the fastening device, and the thermal resistance of the thermal compound. Example: RTH (c - a) for LTO 50 power rating 10 W at ambient temperature + 25 °C Thermal resistance RTH (j - c): 2.5 °C/W Considering equation (1) we have: ΔT = 150 °C - 25 °C = 125 °C ΔT 125 RTH (j - c) + RTH (c - a) = ------- = ---------- = 12.5 °C/W P 10 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 heatsink with RTH (h - a) = 9 °C/W. www.vishay.com 2 For technical questions, contact: [email protected] Document Number: 50050 Revision: 16-Oct-08 LTO 50 Power Resistor Thick Film Technology Vishay Sfernice OVERLOADS POWER RATING CHART In any case the applied voltage must be lower than the maximum overload voltage of 375 V. The values indicated on the graph below are applicable to resistors in air or mounted onto a heatsink. The temperature of the case 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. ENERGY CURVE % RATED POWER ENERGY IN JOULES 100 10 1 75 50 0.1 25 0 0 0.01 10 -6 10 -5 10-4 10 -3 10 -2 20 40 60 80 100 120 140 150 HEATSINK TEMPERATURE IN °C OVERLOAD DURATION IN s MARKING PACKAGING Model, style, resistance value (in Ω), tolerance (in %), manufacturing date, VISHAY trademark. Tube of 50 units ORDERING INFORMATION LTO 50 F 2.7 kΩ ±1% xxx TU50 e3 MODEL STYLE CONNECTIONS RESISTANCE VALUE TOLERANCE CUSTOM DESIGN PACKAGING LEAD (Pb)-FREE ±1% ±2% ±5% ± 10 % Optional on request: Special TCR, shape etc. GLOBAL PART NUMBER INFORMATION L T O 0 5 0 F 2 7 0 0 0 J T E 3 GLOBAL MODEL SIZE LEADS OHMIC VALUE TOLERANCE PACKAGING LEAD (Pb)-FREE LTO 050 F = Radial leads The firts four digits are significant figures and the last digit specifies the number of zeros to follow. R designates decimal point. F=1% G=2% J=5% K = 10 % T = Tube E3 = Pure tin Tube 50 pieces 48R70 = 48.7 Ω 48701 = 48 700 Ω 10002 = 100 000 Ω R0100 = 0.01 Ω R4700 = 0.47 Ω 27000 = 2700 Ω = 2K7 Ω Document Number: 50050 Revision: 16-Oct-08 For technical questions, contact: [email protected] www.vishay.com 3 Legal Disclaimer Notice Vishay Disclaimer All product specifications and data are subject to change without notice. Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf (collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein or in any other disclosure relating to any product. Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any information provided herein to the maximum extent permitted by law. The product specifications do not expand or otherwise modify Vishay’s terms and conditions of purchase, including but not limited to the warranty expressed therein, which apply to these products. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document or by any conduct of Vishay. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding products designed for such applications. Product names and markings noted herein may be trademarks of their respective owners. Document Number: 91000 Revision: 18-Jul-08 www.vishay.com 1