LTC 3350 SW pin ringing

Hello,

When the capacitor stack is charged up or operating in constant voltage (CV) mode at light load the LTC3350 switcher will operate in pulse skip mode replenishing any discharge from leakage currents too keep VCAP at the set voltage. In pulse skip the switcher switches when needed and has periods with both switches off. When both switches are off, a resonate ring can be observed on the SW node. This ring is from the capacitance of the FET gates and the inductor. This is normal and the demo board will also do this when operating with the caps charged up and operating in CV mode. 

Thank you for the quick response,
This the the SW node in the EVM, as you can see it has fewer oscillations after each pulse, trying the pinpoint the reason for the difference.