I have designed a PCB (intended as a prototyping building block) that has a IR2113 high and low side gate driver driving two IRF3205 (55V, 8mΩ, 110A) power MOSFETs in half-bridge configuration:
Upon testing the circuit with a load I found out that while the low side switches quite cleanly there is a lot of ringing at the output of the half-bridge (X1-2) every time the high side switches on. Playing around with the input waveform dead time setting and even removing the load (an inductor with a power resistor in series simulating a synchronous buck converter connected from X1-2 to X1-3) did not reduce this ringing. The measurements below were taken with no load connected (nothing at X1-2 except for the oscilloscope probe).
Apparently the parasitic inductances and capacitances are enough to cause that, but I cannot figure out why the low side works as well as it does. To me both gate drive waveforms look clean enough, with the voltages transitioning the treshold voltage of the MOSFETs reasonably fast. No shoot trough is present when switching. What are the possible causes of the problem, and what measures can I take to reduce the symptoms?
I am aware that there are many very similar questions here and on other sites, but I found the posted answers unhelpful for my particular problem.
While there was a 2200uF electrolytic capacitor at the input (X1-1 to X1-3) to supress transients and noise, it clearly failed to supress any high frequencies. Adding a 100nF capacitor (as suggested in the answer by Andy aka) in parallel with the electrolytic one reduced the ringing at the output (X1-2 to ground) by half and ringing at the supply (X1-1 to ground) by a factor of 10.