As the power capabilities of transistor technology is increasing, the ability of device packages to dissipate heat is greatly enhanced. These specialized packages are regarded as TO package or transistor outline. These high-power version package are adopted by electronic elements so as to improve the heat radiation ability conveniently.

 
To get different power capabilities, resistor manufactures utilize package TO-126, TO-220, TO-227, TO-247, and and TO-263 (D2PAK). The TO packaged resistors are the fastest growing product lines in Microhm, especially TO220 and TO247 cover power ratings from 1 to 140 watts, model range from NLR30, NLR35 to NLR140U.

 
These packages are applied to wide range of applications, such as theater lighting, fuel cells, , EV battery charging, motor drives, precision welding equipment, inverters and other power conversion equipment. The size of resistors tend to be smaller, the appropriate thermal is the key part. Several heat sinking options to facilitate extra power.