Low Range 3 Watt Mil Chip Resistor LRF3W Series * * * * * Tolerances to 1% 3 Watt @70C power dissipation in a compact 1225 package Resistance range from 0.003 to 1.000 Ideal for high current sensing applications Standard Sn/Pb and Pb-free (matte Sn) terminations available IRC's LRF3W-MIL series combines high power capabilities, small chip size, very low resistance and high reliability to handle your current sensing needs. The LRF3W-MIL utilizes high reliability thick film materials and the uninterrupted 2 pad termination on the long sides maximizes the thermal trasport path, improving reliability. Precise measurements can be achieved even at very low values using the specified kelvin pad layout (see Physical Data). Electrical Data Resistance Range() Absolute TCR (ppm/C) Available Absolute Tolerances 0.003 - 0.005 500 10% 0.006 - 0.009 250 5%, 10% 0.010 - 1.000 100 1%, 2%, 5%, 10% Rated Power @ 70C (W) 3.0* Voltage Rating (V) P x R Operating Temperature Range Termination -55C to +150C matte Sn or 60/40 Sn/Pb *Note: 3-Watt rating achieved with 500mm2 Copper pad area around each termination pad. Maximum current is 25 amps. Environmental Data Environmental Test Test Method Specification Maximum Typical Thermal Shock MIL-STD-202 Method 107 Condition F, -65C to +150C 0.25% (+1.0mW) 0.05% (+1.0mW) Short-time Overload 5 Seconds, 3X Rated Power Maximum 25 Amps 0.50% (+0.5mW) 0.01% (+0.5mW) High Temperature Exposure MIL-PRF-55342 100 Hours, 150C, No Power 0.50% (+0.5mW) 0.10% (+0.5mW) 1000 Hours, 70C, Rated Power 1.00% (+0.5mW) 0.20% (+0.5mW) MIL-STD-202 Method 106 0.50% (+0.5mW) 0.10% (+0.5mW) MIL-PRF-55342 0.25% (+0.5mW) 0.05% (+0.5mW) MIL-STD-202 Method 210 0.25% (+1.0mW) 0.05% (+1.0mW) Load Life Moisture Resistance Low Temperature Operation Resistance To Solder Heat Solderability MIL-PRF-55342 95% Coverage 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. Advanced Film 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 LRF3W-MIL Series Issue April 2010 Low Range 3 Watt Mil Chip Resistor Temperature Rise vs Pad Area Temperature Rise (C) 200 100 10 100m2 300mm2 1000m2 Termination Pad Area (each end) 1 watt 2 watts 3 watts Pulse Power Limit Pulse Peak (Watts) 1K Damage Level 100 Safety Zone 10 1ms 10ms 100ms 1000ms Pulse Width Advanced Film Division * 4222 South Staples Street * Corpus Christi Texas 78411 USA Telephone: 361 992 7900 * Facsimile: 361 992 3377 * Website: www.irctt.com LRF3W-MIL Series Issue April 2010 Low Range 3 Watt Mil Chip Resistor Physical Data SUGGESTED MEASUREMENT LAYOUT BOTTOM TOP 0.198" (Board Side) 0.125 ".005 0.020 ".005 Wrap-around plating Overglaze (Stability Enhancer) Protective Overcoat 0.075" Sn or Sn/Pb Plating Ni Barrier Layer High Reliability Resistance Element 0.173" 0.280" 0.250".005 0.035" 0.010" TYP. Alumina Substrate 0.030".005 thickness Conductor 0.032".005 0.023" 0.015" Current Sense Traces Cu Plating To achieve 3-Watt power rating, the copper pad area of each side must be a minimum of 500mm2 . Power Derating Curve Ordering Data Prefix LRC - LRF3WLF - MIL - R020 - F Model LRF3W = 3 watt chip with standard Sn/Pb termination LRF3WLF = 3 watt chip with Pb-free (matte Sn) termination MIL Designator Resistance Code 4-Digit resistance code Example: R050 = 0.050; R005 = 0.005 Tolerance Code F = 1%; G = 2%; J = 5%; K = 10% For additional information or to discuss your specific requirements, please contact our Applications Team using the contact details below. Advanced Film Division * 4222 South Staples Street * Corpus Christi Texas 78411 USA Telephone: 361 992 7900 * Facsimile: 361 992 3377 * Website: www.irctt.com LRF3W-MIL Series Issue April 2010