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Hi people,
Im trying to simulate this nMosfet on LTspice. Am pretty new to this LTSpice but trying to learn bit of pieces here and there.
This is where I'm stuck. I've calculated the basic parameters from the nMosfet Im interested in (Vth, Kp, Cgs and the rest). The Vth is approx 0.94-0.99V but Kp is the interesting bit which I dont really understand. Depending on which Vgs I take, Kp can vary. From Figure 1, Kp can vary between 2.5 to 4.
Based on Figure 1's curve, I've simulated the nMosfet with this parameters on LTSpice:
.model SFet VDMOS(Vto=0.9127 Kp=2.6 Cgs=20p Rd=0.18 Rs=0.18 Cgdmax=38p Cgdmin=5p Lambda=0.05)
Now:
Thank you all in advance. : )
Im trying to simulate this nMosfet on LTspice. Am pretty new to this LTSpice but trying to learn bit of pieces here and there.
This is where I'm stuck. I've calculated the basic parameters from the nMosfet Im interested in (Vth, Kp, Cgs and the rest). The Vth is approx 0.94-0.99V but Kp is the interesting bit which I dont really understand. Depending on which Vgs I take, Kp can vary. From Figure 1, Kp can vary between 2.5 to 4.
Based on Figure 1's curve, I've simulated the nMosfet with this parameters on LTSpice:
.model SFet VDMOS(Vto=0.9127 Kp=2.6 Cgs=20p Rd=0.18 Rs=0.18 Cgdmax=38p Cgdmin=5p Lambda=0.05)
Now:
- Forward Transconductance in spreadsheet is given as 2.0 with unit S whereas LTspice takes A/V2. I dont think you can just implement this value into Kp?
- The calculated and simulated Kp of 2.6 is as shown on the overlapping Figure 1 below. It fits 1.6V pretty well but not the rest. Can someone explain why is that the case and what am I missing to fix this?
- Rds(on) on datasheet is given as 0.36 ohms, however LTSpice takes it as shunt resistance. I dont think this is the same thing? I assume the 0.36 ohms is the series resistance and I've taken it as Rs and Rd (0.18 ohms each?) Is this approach correct?
Thank you all in advance. : )
