Hi everyone,
I created a circuit which contains ;
-1 input,4 isolated output SMPS for sic mosfet driver power supply.
-6 SiC mosfet , 6 schootky diode.
-4 United-chemicon Al-Elct. capacitors as 2 series and 2 parallels.Thus Vmax=900V Totalcap=1mF
-mosfet model: Littelfuse LSIC1MO120E0080
I'am trying my circuit part by part, Now I just set-up one driver one mosfet , four capacitors and smps rails.
In attachments, I shared my inverter stage.
I just put 37R load from terminal A to DC- terminal, I charged to my capacitors around 30V and I applied 100us one pulse to mosfet. I'am adding scope picture.
Yellow:3.3V primary firing signal,
Purple:Vgs,
Green:Vds,
Why my Vds voltage is ringing like that ? The ringing time is about 60us and this is so huge ? Actually Thats different from ringing effect.
I also charged my capacitors to 330VDC but I saw the same kind of waveform with increased magnitude of course.
Do you have an idea about that ?
Really need help. If you have questions ask me please.
Thank you.
I created a circuit which contains ;
-1 input,4 isolated output SMPS for sic mosfet driver power supply.
-6 SiC mosfet , 6 schootky diode.
-4 United-chemicon Al-Elct. capacitors as 2 series and 2 parallels.Thus Vmax=900V Totalcap=1mF
-mosfet model: Littelfuse LSIC1MO120E0080
I'am trying my circuit part by part, Now I just set-up one driver one mosfet , four capacitors and smps rails.
In attachments, I shared my inverter stage.
I just put 37R load from terminal A to DC- terminal, I charged to my capacitors around 30V and I applied 100us one pulse to mosfet. I'am adding scope picture.
Yellow:3.3V primary firing signal,
Purple:Vgs,
Green:Vds,
Why my Vds voltage is ringing like that ? The ringing time is about 60us and this is so huge ? Actually Thats different from ringing effect.
I also charged my capacitors to 330VDC but I saw the same kind of waveform with increased magnitude of course.
Do you have an idea about that ?
Really need help. If you have questions ask me please.
Thank you.
Attachments
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