Fixed Isolated Modules Würth Elektronik Fixed Isolated Modules offer a simple design and an isolated standalone solution. These devices require no external components for operation, which reduces design effort and keeps complexity to a minimum. The MagI³C modules integrate the switching power stage, control circuitry, transformer, and capacitors all in one package. Würth Elektronik Fixed Isolated Modules achieve up to 91% efficiency and are available in various package sizes. This product line includes WE-FIMM and WE-FISM modules, which are designed to provide fast time to market while reducing development costs.