PF1260 Series TO-126 Power Film Resistors • • • • • • • TO-126 Housing Resistances from 0.01 to 51K Ohms Rated Power to 20 Watts Resistance Tolerances to ±0.05% TCR to ±5ppm/K Low Inductance ( <50nH ) Isolated Back Plate SPECIFICATIONS Type Power Rating 1 Heatsink Free Air 2 Resistance Range Thermal Resistance Min Max 3 Tolerances Temperature Coefficients PF1262 20W 1W 5.9K/W 0.01W 51KW ±1% ( R ≥ 0.1W ) ±5% ±50ppm/°C ( R ≥10W ) ±100ppm/°C ( 0.1W ≤ R < 10W ) ±250ppm/°C ( R < 0.1W ) PF1261 5W 0.5W 6.0K/W 0.1W 51KW ±0.1%, ±0.25% ( R ≥ 5W ) ±0.5% ( R ≥ 1W ), ±1% ±5ppm/°C ( R ≥1W ) ±25ppm/°C ( R <1W ) Power rating based on 25°C Flange Temperature Power rating based on 25°C Ambient Temperature 3 Consult Factory for Higher or Lower Values 1 2 Specification Value Maximum Current 25A Temperature Range -55°C to +155°C : PF1262 -55°C to +120°C : PF1261 Dielectric Strength 2000 VAC Max. Operating Voltage 500 V Insulation Resistance >1000 Meg-Ohm Environmental Performance Load Life Humidity Resistance Temperature Cycle DR Test Conditions ±1% + 0.05W 25°C / 90 min ON / 30 min OFF / 1000 hr ±1% + 0.05W 40°C / 90-95% RH / DC 0.1W / 1000 hr ±0.25% + 0.05W -55°C for 30 min / +155°C for 30 min / 1000 hr Solder Heat ±0.1% + 0.05W +350°C / 3s Vibration ±0.25% + 0.05W Riedon Inc. 11/10 300 Cypress Avenue IEC60068-2-6 Alhambra CA 91801 (626) 284-9901 (626) 284-1704 www.riedon.com PF1260 Series TO-126 Power Film Resistors SPECIFICATIONS (continued) Power Rating Notes - Power Derating Curve The PF1260 Series Film Resistors must be attached to a suitable heatsink. The maximum internal resistor temperature is 155°C (120°C for the PF1261). 120 Power ( % ) 100 80 60 PF PF 12 40 To specify an appropriate heatsink use the following formula : 12 62 RqH = TMAX - ( P x RqR ) - TA P 61 20 0 -25 0 25 50 75 100 125 150 175 Ambient Temperature (°C) Where: RqH = Thermal Resistance of Heatsink ( K/W ) RqR = Thermal Resistance of Resistor ( K/W ) TMAX = Maximum Temperature of Resistor TA = Ambient Temperature of Heatsink ( °C ) P = Power Through Resistor ( W ) Mounting Notes The PF1260 Series Film Resistors must be attached to a suitable heatsink. Mount resistor using thermal grease to a clean / flat surface. Use a compression washer to provide 150 to 300 pounds ( 665 to 1330N ) of mounting force. Torque mounting screw to 8 in-lbs ( 0.9 Nm ). Back plate is isolated from both pins. Ordering Information Part Number - Resistance - Tolerance - TCR Example: PF1262 0.5 Ohm 1% 100ppm Riedon Inc. 11/10 300 Cypress Avenue Alhambra CA 91801 (626) 284-9901 (626) 284-1704 www.riedon.com