@robr8554 7 ай бұрын
Thank you for the video, Mano. As always, I enjoy watching your videos. I am still working on this forward converter. The challenges people will discover are finding a good high side gate driver that could be self contained and does not depend on an external boostrap cap. Since both FETs turn ON in phase, the issue with currently available gate drivers is the boostrap cap depends on the bottom FET dc path to charge. since the low and high side FETs are ON, the bootstrap can't charge. The Boostrap cap works fine in complementary synchronous converter, but in real life, I have not found a vendor that can provide an adequate gate driver specifically for this topology. The alternative is you have to design your own. For Hi reliability designs, derating, worst case analysis, and extended temperature ranges make hard but doable with bjts res, caps etc. While it is a great topology and good advantages, the big disadvantage is that high side gate driver. I went back to a single low side driver, and instead of Mosfets, use GaNFETs. They are superior in my mind for Hi-Rel applications. RDSON is low, and they have up to 100V vds. They behave like Mosfet but are very sensitive to gate voltage < 6V. Lastly, for any isolated supply, the challenges is the transformer selection for your application. 90% of time, there is not one COTS transformer that works in every situation, and you have to resort to custom magnetics. This is the part that sucks as it is an iterative process and for hobbyists, it can be very costly.
@manoA98A 7 ай бұрын
Correct. The challenge here consists in the High side mainly, and the forward converter Is seldomly designed. About GaN, they can go up to 650V as a BVDSS and they perform Better than mosfets since they have lower Qg, no Qrr, no body diode and lower Rdson resistance. GaN and SiC dominates the market in High Power and medium Power with High performance. Thirdly, the bridge on the other side with MOSFET Is no joke either, you Will Need isolated references. Isolation Is Always a pain. Btw, I knew you would appreciate another video about forward converter
@robr8554 7 ай бұрын
@manoarrostita970 in my application 100V GaNFETs are sufficient but yes, they go very high....
@Gattuser 3 ай бұрын
Thanks for the video. Few comments. 1. The initial issue with the simulation (why it was so slow) was indeed caused by the high side driver, as E1 negative terminal was connected to GND, while it should have been connected to the L1 (and that's what you've done with MOSFETs latter on). 2. Efficiency calculation didn't work, because you have to include "param" keyword before using math on symbols thar are not defined in the circuit. 3. Your transformer polarity is wrong, it is a two switch forward converter (and not a two switch flyback), hence polarity of both windings should be the same as energy should get transferred during ON cycle.
@manoA98A 3 ай бұрын
Hi! 1)Correct 2)Yes I forgot param 3) Yes, unfortunately I messed up the polarity of the transformer , like you said it's the same energy that it is transfered