b'Interview | Engineer InnovationThe former R&D director of Salcomp believed that planar magnetics would become more popular with the increasing demand for high-power density, so Lauri moved into electromagnetics. He encouraged me to study this technology, which today plays a huge role in power supply and planar magnetics transformation techniques, explains Puranen. I did a lot of R&D work in the area of overall planar magnetics in Finland. Around 2017, adapting it to mass production started to look feasible and we had customer requests for simulation work on this level. Today, from the Shenzhen office in China, we work on quite a few high- Figure 1: The flux density distribution in the core at peak current. The maximum value is less than 0.5 tesla (T), which satisfies the design requirements.power planar transformer designs using Simcenter 3D Electromagnetics. Planar magnetics are a popular solution for applications where available space for magnetic components on printed circuit boards or PCBs have constraints. Compared to traditional wire-wound components, planar components are flatter, making this is a massively interesting technology for engineers like Lauri Puranen who need to be on the cutting edge of charger technology. Looking for the GaN effect in electromagneticsIf you look at the specifics of charger design, there have been quite significant efficiency gains on the semiconductor side. For example, semiconductor materials like GalliumFigure 2: Current density distribution in the primary and secondary coil. The value in the secondary Nitride (GaN) have made a hugecoil is a little bit low, which indicates that material utilization can be optimized further.difference in the performance of high-power transistors operating at highjust make samples by yourself using frequencies, add Puranen. While theyour basic parameter calculation and magnetics side of things has remainedmeasure the results yourself. In a best-the same, so the major percentage losscase scenario, you have a self-made in energy efficiency starts to be solely inprototype in your hands on the same the transformer.day you make your basic calculation, explains Puranen. For planar Electromagnetics & Smart Phonetransformers, however, you first need to Chargers prepare the files in your CAD software. Lauri Puranen explains that he usesThis takes about 1-3 days. Then you Simcenter 3D Electromagnetics sincesend it to the PCB manufacturer and planar transformer design and dealingwait. Depending on the lead time, you with electromagnetic interference ormight have to wait 2-3 weeks before EMI issues are central to smart phoneyou have the first prototype in your charger design.hands. Traditional transformer design is prettyLike traditional transformers, the straightforward. For traditionalparasitic calculations required for planar transformers, its more convenient totransformers are also quite challenging. 87'