LM3478 design gets insanely hot

Mmmm. Aquavit. Once in a while i get some Aalborg Jubilamus variety aperitif, sugary but very tasty.

True, they don't have a SEPIC sim. But the 2nd inductor doesn't carry that much. I really don't see where 8A peaks should be necessary. I had to swing a few designs from boost to SEPIC because clients revised the specs in mid flight. That has not caused any serious changes in peak load.

Or with a real scope. SCNR :-)

I am not all that happy with those Tek lunch-box size scopes. Often I advise clients to go on EBay and bid on a Tek 2465. When it arrives it's like as if someone had turned the lights on.

The other downside that hits in cases like SMPS designs is that many Teks only have 2.5K memory. Not enough. My scope has 25K so I can trigger, digitize at full bore and then blow up individual regions to look at a spike, zoom back out to see whether my RHP-zero situation is kosher, and so on.

Aquavit isn't sweet. But it has to be served ice cold and ideally the glassed should be chilled to where ice crystals form when you take them out. Just make sure you don't have to drive anymore that day.

there numerous different kinds from the neutral almost like vodka, to those with a strong taste of caraway or dill

Many will keep it in the freezer, so theres ice on the bottle and it is thick as cream, but thats only if you don't like it :p

red Aalborg, pickled herring on rye bread with curry dressing and onions is the start of any real lunch in Denmark, one glass for each leg and a few for the third just to make sure the fish has something to swim in :)

-Lasse

I'd prefer saltrulle with it. Of course you need to know someone from Sweden who goes elk hunting every year. Oh, and people with high blood pressure should probably avoid that since it is extremely salty.

Most are not. The Juibilamus aperitif variety is. It is kind of like the difference between Scotch and Drambuie.

One thing that has bothered me is the high frequency ringing on the source trace. Is it a measurement issue or is something else going on?

Looks like the usual. The Vsense scope plots from my clients almost always look like that until I visit and show them. You are measuring millivolts while the FET a few millimeters away sloshes tens of volts around. You are trying to measure the buzz of a bee behind a roaring jet engine.

Plain old crosstalk into the scope probe assy. A direct and correctly terminated coax connection and a good measure of ferrites on that cleans that up quite well.