UNR4-34251R0D

USR UNR 4-3425 4-3825 4-3825H • High Stability • Near Temperature Independency • Lowest Tolerances • Low Capacitance and Inductance • Customized Resistance Values SPECIFICATIONS ELECTRICAL Resistance Range : USR 4-3425/3825 UNR 4-3425/3825 with addional heatsink 3825H note1) 0R05 ... 500R 0R05 ... 500R other resistance values upon request / power rating depending on resistor value 3 W (70°C) without heatsink 5 W (20°C) for 3825H 30 W* 50 W* * with heatsink 3.5 K/W 2.1 K/W Power Rating : Thermal Resistance Rthj-c : Tolerances from 0R05 from 10R from 50R Stability : : : : : 0.1%, 0.25%, 0.5%, 1% 0.05%, 0.1%, 0.25%, 0.5%, 1% 0.01%, 0.02%, 0.05%, 0.1%, 0.25%, 0.5%, 1% 0.01% max. ±5 ppm/K (-55...155)°C typ. ±3 ppm/K (-55...125)°C upon request ±1 ppm/K (0...60)°C 750 VDC 15 A < 1 µV/K Temperature Coefficient : Voltage Proof Max. Current Thermal EMF : : : ENVIRONMENTAL Operating Temperature Range : : : : : : -55°C...155°C NiCr-Foil Al2O3 AlN Epoxy + heatsink aluminium Cu, tinned, 4-pin 1.0 Nm MECHANICAL Resistor Material Substrate Housing Connector Material Max. torque backplate note1): Specially designed for applications with fast changing electrical load. Willow Technologies Ltd. Shawlands Court, Newchapel Road, Lingfield, Surrey, RH7 6BL, UK Tel. + 44 (0) 1342 835234, Fax. + 44 (0) 1342 834306, e-mail sales@willow.co.uk web www.willow.co.uk USR UNR 600 4-3425 4-3825 4-3825H TEMPERATURE COEFFICIENT +5 ppm/K 400-5 ppm/K dR/R (ppm ) 200 0 +2,2 ppm/K -200 -400 -600 -50 -25 0 25 50 75 Tem perature (°C) -1,8 ppm/K No minal-dR/R No minal-Spread +/-2,3 ppm/K No minal-Spread +/-2,3 ppm/K 100 125 DERATING CURVE Power ( % from nominal power) 120 100 80 60 40 20 0 25 50 85 100 115 130 145 155 Temperature of the backplate (°C) DIMENSIONS USR/UNR 4-3425 USR/UNR 4-3825 and 4-3825H Dimensions in mm HOW TO ORDER UNR 4-3425 1R0 D 0.1% TK1 USR 4-3825 10R D 0.5% 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 sales@willow.co.uk web www.willow.co.uk