Low Resistance Metal Element Resistor LOB Series • • • • • • • Low TCR High stability over life Tolerances from ±1% to ±5% Ultra low resistance values (0.005Ω to 0.1Ω) Inherently non-inductive (≤.02 µh @ 0.5MHz) Available in 1W, 3W, and 5W rated packages Lead free RoHS compliant construction available DESCRIPTION: The LOBΩ Series power precision metal element resistors feature resistance values down to 0.005 with virtually no inductance. Available in 1, 3, and 5 watt rated axial leaded packages, these resistors are compatible with automatic insertion equipment. APPLICATIONS: • Switchmode and linear power supplies • Automotive current-sensing circuits • Instrumentation • Regulators CONSTRUCTION: The LOBΩ Series resistors feature tinned copper leads welded directly to a low-temperature coefficient resistance element in a highly automated proprietary process. The leaded resistor elements are then encapsulated in a molding compound. Specifications Style Continuous Power Dissipation @ 25°C in free air (watts) Overload Power for 5 seconds (watts) LOB-1 1 5 √1 x R 175 LOB-3 3 15 √3xR 175 LOB-5 5 25 √5xR 175 Maximum Working Voltage (volts) Maximum Storage Temperature (°C) *Power Dissipation - The maximum wattage rating depends upon the amount of heat which can be transferred to the surroundings while not exceeding the maximum element temperature. Ambient air temperature, velocity of cooling air, thermal resistance of heat, and the temperature of surrounding objects will affect this transfer, and must be taken into account when selecting a resistor. Environmental Testing Test Parameters MIL-STD 202 MAX %∆R * Unit Load Life (2,000 hours) Method 108 ±1% %∆R Thermal Shock Method 107 ±1% %∆R Vibration Method 204 ±0.5% %∆R Mechanical Shock Method 213 ±0.5% %∆R Dielectric Strength Method 301 ±0.5% %∆R Insulation Resistance Method 302 >1011 Ohms *±0.0005 ohm allowance for test/contact error. General Note IRC reserves the right to make changes in product specification without notice or liability. All information is subject to IRC’s own data and is considered accurate at time of going to print. Wire and Film Technologies Division • 4222 South Staples Street • Corpus Christi Texas 78411 USA Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com A subsidiary of TT electronics plc LOB Series Issue October 2008 Sheet 1 of 3 Low Resistance Metal Element Resistor Physical Data connect point connect point C d D L l Dimensions (Inches (mm)) Style LOB-1 LOB-3 LOB-5 L D C l 0.390 ± 0.010 (9.9 ± 0.3) 0.140 ± 0.008 1.31 1.50 ± 0.125 0.0305 ± 0.002 (3.6 ± 0.2) (33.274) (38.1 ± 3.2) (0.813 ± 0.051) 0.560 ± 0.010 0.2100 ± 0.010 1.31 1.375 ± 0.125 0.0305 ± 0.002 (14.224 ± 0.254) (5.334 ± 0.254) (33.274) (34.925 ± 3.175) (0.813 ± 0.051) 0.920 ± 0.010 0.330 ± 0.010 1.670 1.250 ± 0.125 0.040 ± 0.002 (23.368 ± 0.254) (8.382 ± 0.254) (42.418) (31.750 ± 3.175) (1.016 ± 0.051) TCR (ppm/°C) Temperature Coefficient of Resistance vs. Resistance Value Power Derating Percentage vs. Free Air Ambient Temperature: 400 100 300 75 200 50 100 0 LOB-1 LOB-3 LOB-5 0 d 25 50 75 100 Resistance (ohms x 10-3) Wire and Film Technologies Division • 4222 South Staples Street • Corpus Christi Texas 78411 USA Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com 25 0 0 25 50 75 100 125 150 175 Ambient Temperature (°C) LOB Series Issue October 2008 Sheet 2 of 3 Low Resistance Metal Element Resistor Ordering Data To order, specify style, resistance value, tolerance, and package type as in the following example: Sample Part No. LOB-3 R010 F LF LT IRC Type LOB-1 (1 watt) LOB-3 (3 watt) LOB-5 (5 watt) Resistance Value 0.005Ω 0.02Ω 0.01Ω 0.025Ω 0.015Ω 0.03Ω 0.04Ω 0.05Ω 0.07Ω 0.08Ω 0.1Ω Tolerance J = 5%, H = 3%, F = 1% Lead-Free RoHS Compliant Packaging LT = Lead Tape, 500 pcs. min. LOB-1 = 3,500 pcs. max. LOB-3 = 1,250 pcs. max. LOB-5 = 800 pcs. max. BLK = Bulk Pack, 500/box Wire and Film Technologies Division • 4222 South Staples Street • Corpus Christi Texas 78411 USA Telephone: 361 992 7900 • Facsimile: 361 992 3377 • Website: www.irctt.com LOB Series Issue October 2008 Sheet 3 of 3