- Telcodium produces the world’s highest efficiency power modules. By harnessing the unique characteristics of GaN Mosfets and combining it with Telcodium’s patented technologies, Telcodium offers a unique line of High-Efficiency Modules (HEMs). The Telcodium HEMs make it simple for all hardware designers to rapidly build efficient and reliable power supplies. The Telcodium product line also includes all the elements required to build an AC-DC power supply with EMI filtering, monitoring, and logging functions.