Thank you for rightfully pointing out the current spike. I have observed this in SiC, GaN and even in diamond devices. The effect is similar to those caused by the reverse recovery current of Si diodes, although, the magnitude of current spike is much smaller in wide band gap devices, where as you pointed out, is due to the device capacitance (and not due to rev recovery of diode or bodydiode). Your lectures provide a great learning experience.
Thanks for your video. For Si diode, is junction capacitance charge included in Qrr in the datasheet? Or Qrr is only the reverse charge without Cj charge?
At 31:46 how did you modeled the non linear cap ? Like in your Coss video ? You also said that you want to keep it brief so you hold that detail... details are important.. Please do not hold them 😊
Hi Catalin, Yes, I apply the same method as for simulating the Coss which is also detailed in ua-cam.com/video/_rj-Vw5taJU/v-deo.html. Considering the fact that the "average view duration" of my videos is 6.23 minutes, there seems to be a need to make them as short as possible :-)
why the Vd voltage drop until IF is zero I think the VD will drop when the Vgs equal to VT and then Coss discharge So Vd would drop and then the mosfet become constant current the Vd will drop dramatically?
I am not sure that I follow your question. The situation in this minute is that Vgs is already above VT, Vd starts to drop as soon as IF reaches zero, Coss is not shown and is included in Cs.
Sam, I hear people referring to SiC diodes as Schottky diodes. Is these really the same thing ? The Schottky diodes I am familiar with (say, 1N4818 and 200V and below Schottky diodes) have a negative temperature coefficient of Vf. Higher temperature gives lower voltage drop. But SiC diodes I have been using (650V) have a positive temperature coefficient. This is kind of confusing to me. What do you think about this ?
Hi boB, as I said in video and Prem wrote, Schottky diodes are based on metal to semiconductor junction. The maximum achievable breakdown voltage and the Temp coefficient are dependent on the type of the semiconductor.
Just to clarify. SiC diodes are Schottky diodes because they are based on a junction between metal and SiC. The "regular" Schottky diodes are based in metal to Si junction. Metal to semiconductor junction has an insignificant stored charge. This is why Schottky diodes do not have the reverse recovery problem.
Thank you for rightfully pointing out the current spike. I have observed this in SiC, GaN and even in diamond devices. The effect is similar to those caused by the reverse recovery current of Si diodes, although, the magnitude of current spike is much smaller in wide band gap devices, where as you pointed out, is due to the device capacitance (and not due to rev recovery of diode or bodydiode). Your lectures provide a great learning experience.
ujjwal karki Thanks
I wanted to thank you for posting this and your other videos . They are really informative .
Thanks for comment.
I like your teaching style.
Thanks for comment.
Hi mister Ben-Yaakov, thank you very much to share this with me!
😊
Thanks for your video. For Si diode, is junction capacitance charge included in Qrr in the datasheet? Or Qrr is only the reverse charge without Cj charge?
Hi Hao, Good question. Qrr is a measured parameter so I it takes into account all charges.
Wow! Thank you
Thanks for comment.
At 31:46 how did you modeled the non linear cap ? Like in your Coss video ?
You also said that you want to keep it brief so you hold that detail... details are important.. Please do not hold them 😊
Hi Catalin, Yes, I apply the same method as for simulating the Coss which is also detailed in ua-cam.com/video/_rj-Vw5taJU/v-deo.html. Considering the fact that the "average view duration" of my videos is 6.23 minutes, there seems to be a need to make them as short as possible :-)
Hi Sam,
can you please provide the reference literature you used for this video. Thanks
I have been using Datasheets and application notes which are referenced. The model based explanations are my own. I don't recall a refernce to that.
Sir, do you have video talk about Mosfet turn on and turn of ringing
Have you seen
ua-cam.com/video/kNTVhgawljg/v-deo.html
ua-cam.com/video/zJQM842clcM/v-deo.html
@@sambenyaakov I will see that thank you
why the Vd voltage drop until IF is zero
I think the VD will drop when the Vgs equal to VT and then Coss discharge So Vd would drop and then the mosfet become constant current the Vd will drop dramatically?
"why the Vd voltage drop until IF is zero "? please indicate the relevant minute of the video
@@sambenyaakov 18:56
I am not sure that I follow your question. The situation in this minute is that Vgs is already above VT, Vd starts to drop as soon as IF reaches zero, Coss is not shown and is included in Cs.
Sam, I hear people referring to SiC diodes as Schottky diodes. Is these really the same thing ? The Schottky diodes I am familiar with (say, 1N4818 and 200V and below Schottky diodes) have a negative temperature coefficient of Vf. Higher temperature gives lower voltage drop. But SiC diodes I have been using (650V) have a positive temperature coefficient. This is kind of confusing to me. What do you think about this ?
SiC is not same as schottkey. Later one is junction of metal and semi conductor.
Hi boB, as I said in video and Prem wrote, Schottky diodes are based on metal to semiconductor junction. The maximum achievable breakdown voltage and the Temp coefficient are dependent on the type of the semiconductor.
Ok. But i hear people talk as though SiC are Schottky and I know they are different animals.
Indeed. but: both a a bear and a fox are still animals.
Just to clarify. SiC diodes are Schottky diodes because they are based on a junction between metal and SiC. The "regular" Schottky diodes are based in metal to Si junction. Metal to semiconductor junction has an insignificant stored charge. This is why Schottky diodes do not have the reverse recovery problem.
thanks SBY!
Thanks for comment. Manishma?
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