Use Snubber Circuits to Dampen Noise in DC-DC Converters (Download)
Power designers are constantly pursuing DC-DC converter designs with higher efficiency and smaller sizes. These gains are often achieved by using faster switching frequencies to shrink inductors and capacitors in the solution.
However, that also increases the impact of parasitics, which are unintended inductances and capacitances emanating from PCB traces and power FETs themselves. At fast switching speeds, interaction with these parasitics can cause significant voltage overshoot and ringing at the switching (SW) node.
