How To Size A Snubber Capacitor For Your Power Supply

Power supply circuits increasingly use wide-bandgap semiconductors instead of traditional silicon insulated-gate bipolar transistors (IGBTs) due to their superior performance and decreasing costs. However, substituting a vital component like a semiconductor can affect the component selection process, requiring engineers to reconsider factors such as voltage rating, capacitance value, equivalent series resistance (ESR), and equivalent series inductance (ESL) in the design process.

This white paper will focus on deriving a basic snubber for a simple switching circuit, which can help in understanding how these switches impact snubber capacitor sizing. While snubber circuits are much more complex in practice, this exercise can provide a useful foundation for understanding the effects of wide-bandgap semiconductors on power supply circuits.