Power Film Resistors are a type of resistor product which can maintain high stability performance while subjected to high current flow. At the same time heat will be generated during the resistor’s operation, so a thermal management solution is needed for heat dissipation. Most power film resistors are designated in an industry-standard IC package, e.g. TO-220 and TO-247, for directly mounting on a heatsink. Choosing the right heatsink can often be done by looking at the datasheet. For example the LTO050F10R00JTE3, from the LTO 50 series from Vishay Sfernice,
The thermal resistance is 2.5 C/W (free air at 25C). If the resistor is operating at the power rating 10W at ambient temperature +25C, with thermal grease, a heatsink with 9 C/W is needed.
Selecting a Suitable Heat Sink