Greetings. I'm making a high power boost converter, supposed to deliver constant current at 15-50V from about 12V input. 100KHz frequency. There are problems, however. There was a lot of ringing at the switch node - meeting point of the diode, inductor and MOSFET. 5.8Mhz clear decaying sine wave, got rid of the most of it with an RC snubber - 5Ω, 10nF. There is still, however, a big peak at the moment the switch closes. 15.5V 7.75A out, 12V 10A in (20V vertical) 21V 10.5A out, 20A in. The spike is already at nearly 60V. At this rate the spike will exceed the 100V rating of the transistor well before the 100A maximum input current i was aiming for. There is a TVS diode across it, but i doubt it would help much to prevent the explosion. Is there any way to get rid of this spike? I suspect the devil is in the layout, but i'm not good enough to determine just what it is. Here is what it looks like, input on the right, output to the left: http://orbides.1gb.ru/img/bc-side.jpg http://orbides.1gb.ru/img/bc-top.jpg I tried moving the wires around, with no noticeable effect, and there is not much i can do to shorten the wires. The MOSFET package is claimed to be "Low internal inductance", so that parasitic inductance must come from somewhere else, right?