great knowledge here. thanks how to calculate Mosfet parameters like Kp,CGSO, CGDO for modelling an Mosfet from datasheet. i did see your other video but not clear as you used mathcad. Could you share mathcad or Excel that you made for calculating these parameters
can someone please explain why the gate current is negative at t=0 (-500mA)? shouldn't it be at +500mA at t=0 and then exponentially decrease as voltage across the capacitor increases?
Hi Jeeva, Sorry for the delay in responding to your question. I am slowly recovering from Covid. Regarding your question, I am plot the current thru V2. In spice when you plot the current of a voltage source, if it is negative current, then that means that the voltage source is supplying the current and the current is flowing from left to right into the Cgs of the mosfet. When the current in a voltage source is positive, then the current is being dissipated by the voltage source and flows from right to left. I hope this clears you doubts. Robert Bolanos
can we find miller platue voltage from the data sheet? if yes then how is there any formula to find that. moreover you have wrote the equation for the fall time it would be helpful if you told the equation to find the rise time thank you
Hi itsrandom, the vmiller platue can be approximated as VT (Threshold Voltage). The erorr is small enought to make that approximation! Sorry for the delay answer. I just saw it.
Hello! one double, MOSFET starts to conduct before Miller region, i.e it conducts at V threshold, but as per your explanation drain voltage starts to change at beginning of platue . Please clarify
That is correct, the Mosfet starts to conduct or turn on after you exceed the threshold voltage. The miller voltage is slightly above that. The drain will start to drop and will inject current thru the miller capacitor which creates the miller plateau. After the drain goes to zero voltage the Cgs will start to charge from the miller plateau to its final voltage. I hope this makes sense. Robert
Hi Isac, I assume you are asking about the gate peak current. Keep in mind that Cgs can be large any from 1nF to 10 nF. If you input pulse has a fast slew rate,(very faast), the large current is due to the charging of Cgs. I hope this make sense if not , let me know. Regards Robert
This was so great.. thanks a lot
As always, very interesting and well explained, thank you.
Thank you pa4tim for the kind comments. Robert
Glad you like the video
Hello Robert , Good explanation . Thank you. ! Would you pleas post videos on PFC ?
I always enjoy your videos. thank you.
Thank you Yafhiyah for the comments. Best wishes, Robert
great knowledge here. thanks how to calculate Mosfet parameters like Kp,CGSO, CGDO for modelling an Mosfet from datasheet. i did see your other video but not clear as you used mathcad. Could you share mathcad or Excel that you made for calculating these parameters
Please send email to rbola35618@aol.com and I will send my Mathcad file.
Why is Cgate = 245pF where as datasheet value is 260pf? is it 260pf - Crss?
Hello again, If the SiC (SCT2080KE) MOSFET has in its datasheet as Rg = 0 ohms, how could this analysis be applied?. Regards
Esteban Buenrostro Rgate is added externally to minimize gate ringing. So you use this value and not the internal Rgate.
can someone please explain why the gate current is negative at t=0 (-500mA)? shouldn't it be at +500mA at t=0 and then exponentially decrease as voltage across the capacitor increases?
Hi Jeeva, Sorry for the delay in responding to your question. I am slowly recovering from Covid. Regarding your question, I am plot the current thru V2. In spice when you plot the current of a voltage source, if it is negative current, then that means that the voltage source is supplying the current and the current is flowing from left to right into the Cgs of the mosfet. When the current in a voltage source is positive, then the current is being dissipated by the voltage source and flows from right to left. I hope this clears you doubts. Robert Bolanos
@@RobertBolanos how are you now i hope you are well, thanks alot for your videos.
@@Ahmad-gn1pd Hi Jeeva, I am doing much better. The covid lasted around around 3 months. Thanks again for asking. Take care and be safe.
@@Ahmad-gn1pd Hi Ahnad, I am doing much better. The covid lasted around around 3 months. Thanks again for asking. Take care and be safe.
@@RobertBolanos I hope you are always in good health. And thanks again for your amazing content💐
can we find miller platue voltage from the data sheet? if yes then how is there any formula to find that. moreover you have wrote the equation for the fall time it would be helpful if you told the equation to find the rise time thank you
Hi itsrandom, the vmiller platue can be approximated as VT (Threshold Voltage). The erorr is small enought to make that approximation! Sorry for the delay answer. I just saw it.
Hello! one double, MOSFET starts to conduct before Miller region, i.e it conducts at V threshold, but as per your explanation drain voltage starts to change at beginning of platue . Please clarify
That is correct, the Mosfet starts to conduct or turn on after you exceed the threshold voltage. The miller voltage is slightly above that. The drain will start to drop and will inject current thru the miller capacitor which creates the miller plateau. After the drain goes to zero voltage the Cgs will start to charge from the miller plateau to its final voltage. I hope this makes sense. Robert
@@RobertBolanos Hi! whether the Mosfet will conduct during 2nd region ?
Why peak occurs in transition period in Vout ?
Hi Isac, I assume you are asking about the gate peak current. Keep in mind that Cgs can be large any from 1nF to 10 nF. If you input pulse has a fast slew rate,(very faast), the large current is due to the charging of Cgs. I hope this make sense if not , let me know. Regards Robert
so cool!
Excuse me for this quiestion, Is it the same the "switching characteristics" and "dynamic characteristics". Many thanks
Yes, they are the same thing.
@@RobertBolanos Sorry for asking again, and it is the same term to Transient Response?. Many thanks
Esteban Buenrostro Esteban, yes it the same.
This thing is same for igbt
good question, i want to know too. i believe so
which software is this
The spice simulation is Topspice from Penzar Development.
F.Y.I.: The name of that video is now (12/1/2022), "How to model a MOSFET using a datasheet." and not "How to model a IRF624"
Thank you Mike for the correction!