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I'm working on a 5 V to 15 V boost converter with a low-current output (~5-10 mA). The supply runs in discontinuous mode because this is a small space-constrained circuit with a small inductor.

I did a simulation and noticed that the switch node (before the diode, not the output) was ringing quite a bit when the inductor is turned off. The ringing is about 10 Vpp at a frequency about 30 MHz. The switcher runs at 1.2 MHz switching speed.

My question is how do I know when this ringing becomes a problem? I've simulated an RC snubber using some calculations I found in an app note, and it completely gets rid of the ringing; of course I'd rather not add it unless I need to. Some articles seem to indicate that the ringing is fine as long as it doesn't cause EMI problems or exceed the limits of the components, but information has been sparse. What kind of effects could this have?

Ringing at 30 MHz

sgdsgyhetwaraw
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    Have a look at https://electronics.stackexchange.com/questions/246301/snubbing-dcm-nonsynchronous-buck-converter – Lars Hankeln Nov 10 '22 at 06:07
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    The decaying LC ring is wasting power because there are losses mainly in the inductance .If efficiency is really important then such losses should be dealt with. – Autistic Nov 10 '22 at 06:22

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