FHR FNR 2-T238 4-T238 • Extremly Low-Ohm • High Stability • Two And Four Circuit Technology • Low Temperature Coefficient • Low Electrical Noise • Low Inductance SPECIFICATIONS ELECTRICAL FHR 2/4-T238 FNR 2/4-T238 Resistance Range : R01/R001...100R R01R001...100R Power Rating : 60 W* *with heatsink 80 W* 1.3 K/W 1.0 K/W Thermal Resistance Rthj-c : Tolerances : 0.5%, 1%, 2%, 5% (others upon request) Stability : 0.1%, 0.2%, 0.5% (depends on stress) Temperature Coefficient : ±15 ppm/K (20... 60)°C FHR/FNR2-238 TCR-Shift (see table next page) Voltage Proof : 2.5 kV DC Thermal EMF : < 1 µV/K Max. Current : 40 A 45 A higher upon request ENVIRONMENTAL Operating Temperature Range : MECHANICAL Resistor Material Substrate Housing Connector Material : : : : -40°C...130°C Metalfoil CuNiMn (nach DIN 17471) Al2O3 AlN Epoxy Cu tinned, 2- and 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 FHR FNR 2-T238 4-T238 TEMPERATURE COEFFICIENT FHR/FNR 2-T238 2000 + 15 ppm/K 300 1000 250 TCR - Shift (ppm/K) dR/R (ppm ) 0 -1000 - 15 ppm/K -2000 -3000 Limit 2 (3σ) -4000 -5000 150 100 50 Nominal dR/R -6000 -7000 -40 200 0 Limit 1 (3σ) -20 0 20 40 100 80 60 120 2 140 5 10 20 50 Temperature (°C) DERATING CURVE Power ( % from nominal power) 120 100 0,5% 80 0,2% % 0,1% 60 40 20 0 25 DIMENSIONS 50 85 100 100 Resistance Value (m Ohm ) 115 130 Tem perature of the backplate (°C) * screw terminal M4 Standard: Pin G (width= 6.35) leads curved Dimensions in mm 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 FHR FNR 2-T238 4-T238 ATTACHMENT VARIATIONS FHR 2-T238 / FNR 2-T238 FHR 4-T238 / FNR 4-T238 1 - U1 2 - U2 3 - I2 4 - I1 Dimensions in mm HOW TO ORDER FHR 2-T238 1R1 G 1% FNR 4-T238 R001 F 2% 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