I would appreciate a bit of friendly advice. Can you please point me in the right direction?
I am trying to push the LT3743 to a ~40A solution. I am using it to drive a laser at dc. No PWM. Just 12V to about 40A (Vf is about 1.25V at this current).
I have downloaded and made some adjustments to the LT3743 LTSpice file: the inductor and sense resistor, of course, needed to change. Current at the laser looks good. However, I see the top and bottom side FETs have a significant current transient right when the high-side fet is turned on (HG driven high, LG is low already). It is a current that passes right though both FETs - seemingly from VIN to GND for just a couple of ns . I would appreciate a bit of advice on how to dampen this a bit. I have tried the usual suspects within the circuit, but with no luck.
It does seem to be FET dependent - I can make it "tolerable" if I switch both FETs to BSC009NE2LS5I, which should be overkill for this circuit.
Below are two pics showing the transient. I have also attached the .asc files if you are so inclined to look at them.
Top Fet is BSC080N03LS, Bottom FET is BSC011N03LS
Top and Bottom FET are BSC009NE2LS5I.