Thanks, it seems a little odd that in the datasheet "ABS MAX's" it says the SW pin should be no higher than "vin+0.3v".......whereas the vin pin can be up to 100v......so why cant the SW pin be exposed to 100V too? (even if the vin is only actually 60v).
I must admit it seems odd that the diode hasnt clamped the sw pin to vin, but as you say it coudl be a scope artefact.....this was scoped with a kynar twisted pair flying probe soldered to SW (and gnd) and the gnd wrapped around the scope ground barrel and the SW wrapped tightly to the probe tip...ie scope "gangling" gnd clip not used.
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I have 1uF MLCC right on the Vin pin.
There is a further 5.4uF further away from the LM5019...though they are the othger side of a small 0805 ferrite bead