How to evaluate voltage spikes of switching power supply layout parasitic inductance

The current trend in switching power supplies is to use wide bandgap devices because these devices support higher switching frequencies and higher edge rates. These two factors, in turn, can drive power supplies to become smaller, lighter and cheaper. If you could switch more frequently, the magnetic material and capacitor would become smaller. Higher edge rates lead to greater efficiency: if you can reduce conversion losses, less heat is dissipated and the transistor can complete conversions faster. But these high slew rates also have a downside, in particular, large spike voltages and noise due to layout parasitics, especially the inductance of the PCB layout traces. This seminar will discuss how to evaluate these parasitic inductances and voltage spikes.

• Chapter 1：How to evaluate voltage spikes of switching power supply layout parasitic inductance (14 minutes and 39 seconds)