USR 4-1414 • Highest Stability • Near Temperature Independency • Lowest Tolerances • Low Capacitance and Inductance • Customized Resistance Values SPECIFICATIONS ELECTRICAL Resistance Range : 0R5 ...100R Power Rating : 0.8 W without heatsink (70°C) 25 W with heatsink Thermal Resistance Rthj-c : < 4.2 K/W Tolerances from 0R5 from 1R : : : 0.1%, 0.25%, 0.5%, 1% 0.01%, 0.05%, 0.1%, 0.25%, 0.5%, 1% Stability : 0.01% Temperature Coefficient : max. ±5 ppm/K (-55...155)°C typ. ±3 ppm/K (-55...125)°C upon request ±1 ppm/K (0...60)°C Voltage Proof : 1.5 kVDC Thermal EMF : < 1 µV/K ENVIRONMENTAL Operating Temperature Range : MECHANICAL Resistor Material Substrate Housing Connector Material : : : : -55°C...155°C NiCr-Foil Al2O3 (upon request AlN) Plastic + Epoxy Cu-tinned / 4-pin Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, UK Tel. + 44 (0) 1342 835234, Fax. + 44 (0) 1342 834306, e-mail [email protected] web www.willow.co.uk USR 4-1414 TEMPERATURE COEFFICIENT 600 +5 ppm/K dR/R (ppm ) 400-5 ppm/K 200 No minal-Spread +/-2,3 ppm/K 0 +2,2 ppm/K -200 -1,8 ppm/K No minal-dR/R -400 No minal-Spread +/-2,3 ppm/K -600 -50 -25 0 25 50 100 75 125 Tem perature (°C) DERATING CURVE without heatsink with heatsink 120 80 Power ( % from nominal power) pow er (% from nom inal pow er) 100 60 40 20 0 100 80 60 40 20 0 25 40 55 70 85 100 115 130 145 155 25 Ambient Temperature (°C) 50 85 100 115 130 145 Temperature of the backplate (°C) DIMENSIONS Dimensions in mm HOW TO ORDER USR 4-1414 1R5 0.1% TK3 USR 4-1414 0R1 0.1% TK3 Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, UK Tel. + 44 (0) 1342 835234, Fax. + 44 (0) 1342 834306, e-mail [email protected] web www.willow.co.uk 155