With more efficient switching at any given frequency, power MOSFETs based on superjunction technology have become the industry norm in high-voltage switching converters. Previously, the dominant design platform for high-voltage devices was based on planar technology. However, fast switching at high voltages poses its own challenges in AC/DC power supplies and inverters. Designers making the transition from planar to superjunction MOSFETs often have to accommodate EMI, voltage spikes, and noise-related concerns by compromising switching speed. This application note will compare the characteristics of the two platforms so that the benefits of superjunction technology are fully understood and utilized.