General Purpose Failsafe Molded Wirewound Resistor SP20/SP20F Series • • • • • • • • • SP20F Fusible ±5%, ±10% tolerance 0.1 ohm to 1200 ohms F version has flame resistant coating 1 watt rated with 1/2 watt dimensions Drop-in replacement for BW20/BW20F Weldable and solderable magnetic lead TCR’s as low as ±150 ppm/°C standard (custom TC’s available) Lead free, RoHS compliant construction available 3 1 4 2 (See notes below) Electrical Data IRC Type SP20 SP20F EIA RS-344 Style CRU1 CRU1 RC20/RC32 RC20/RC32 0.1Ω to 1200Ω 0.1Ω to 1000Ω ±5%, ±10% ±5%, ±10% MIL-R-11 Style Resistance - Std. Tolerance - Std. 1 watt @ 50°C 1 watt @ 50°C 3/4 watt @ 70°C 3/4 watt @ 70°C --1/2 watt @ 100°C Derating to 0 @ 160°C Derating to 0 @ 160°C Power Rating √PR √PR Resistance Dry Wet 10,000 Meg 100 Meg 10,000 Meg 100 Meg Min. Dielectric ATM 700V 700V Reduced Pressure 450V 450V 120°C @ 1 watts 120°C @ 1 watts 5% 5% Negligible Negligible Max. Continuous Working Voltage Min. Insulation Withstanding Volts (RMS) Hotspot Temperature Rise Typical Load Life Current Noise 1. Resistive Element All resistor types have resistance alloy winding on a braided fiberglass substrate. Intermediate silicone coatings are used to enhance processibility and to provide protection to the resistive element. 2. Termination The SP-20 and SP-20F resistors are terminated using an alloy coated copper flashed steel lead welded to a cap of the same material. This termination assembly is mechanically crimped, utilizing an improved crimp design, to the resistive element. 3. Encapsulation The SP-20 and the SP20F are encapsulated utilizing a compression molded phenolic plastic material. The SP-20F has a flame resistance coating applied over the resistive element to provide flammability protection when destructive overloads may occur. 4. Marking All products are marked utilizing heat and solvent resistant color code bands consistent with EIA/MIL requirements. The first band is double width to designate wirewound construction. A fifth band, blue in color, is used for flameproof identification. 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 SP20/SP20F Series Issue December 2008 Sheet 1 of 3 General Purpose Failsafe Molded Wirewound Resistor Environmental Data Test SP20 SP20F <1R <±800 ≥1R <±150 <1R <±800* ≥1R <±150 700V 700V Momentary Overload 5% 5% Low Temperature Operation 5% 5% Temperature Cycle 5% 5% Humidity 5% 5% Load Life 5% 5% Terminal Strength 5% 5% Resistance to Solder Heat 5% 5% No Failures No Failures Temperature Coefficient (ppm)* Dielectric Withstanding Voltage (RMS) Solderability Physical Data D A B C Dimensions (Inches and (mm)) IRC Type SP20 SP20F A B C D 0.390 ± 0.010 (9.91 ± 0.25) 0.140 ± 0.008 0.032 ± 0.002 1.50 ± 0.126 (3.56 ± 0.20) (0.813 ± 0.05) (38.1 ± 3.2) 0.390 ± 0.010 0.140 ± 0.008 0.032 ± 0.002 1.50 ± 0.126 (9.91 ± 0.25) (3.56 ± 0.20) (0.813 ± 0.05) (38.1 ± 3.2) 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 SP20/SP20F Series Issue December 2008 Sheet 2 of 3 General Purpose Failsafe Molded Wirewound Resistor SP-20F Power Derating Curve 2.5 2.5 2.0 2.0 Power (watts) Power (watts) SP-20 Power Derating Curve 1.5 1.0 0.5 0 0 50 100 150 1.5 1.0 0.5 0 200 0 SP-20F Typical Fusing 150 200 SP-20 and SP20F Temperature Rise Chart 25 120 15 10 8 0.1 ohm 1 ohm 10 ohm 100 ohm 1000 ohm 6 4 0 20 40 60 80 100 Temperature Rise (°C) 20 Power (watts) 100 Ambient Temperature (°C) Ambient Temperature (°C) 2 0 50 100 80 60 40 20 0 Time (seconds) 0 0.5 1.0 1.5 2.0 Power Input (watts) Ordering Data Sample Part No. SP - 20 150Ω 5% LF IRC Type Power Resistance Range Tolerance Lead Free Construction 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 SP20/SP20F Series Issue December 2008 Sheet 3 of 3