Small Signal Model Example

In this video, I solve a Small Signal Model Example problem for transistor amplifiers. In doing so, the process of using the small signal model is explained.

[@tiagofalcao8161]

Great video, cheers!

[@Emma-dd1fc]

Wow! Thanks for this 🙏

[@arashyusefi1889]

Thanks 😊👍🙏💯

[@qemmm11]

Much appreciated Sir 😊 MOSFET drain feedback bias One minute A: Id=k(vd-vt)^2 15-vd/15=0.25(vd-1.5)^2 Too lazy to solve the value of ax2+bx+c=0 vd gm=2k(vgs-vt)^2=2k*(id/k)^1/2=2*(k*id)^1/2 (Id/k)^1/2=vgs-vt B: vo=-u*vi*(rl'/ro+rl') vo/vi=41.2*(3.75/(68.75+3.75))=154.5/71.5=-21.6v/v C: Rin=rg/(1-A)=10/22.6=3.164M ohm Ro=ro//rd//RL//(rg/(1-1/av))=~

[@anonymous_IIT]

Vd=Vg in step 1 makes no sense! What is the logic for that assumption?

[@talhajat3301]

did you figure it out? im confused too

[@dr-mnizam]

@@talhajat3301 Here is the video for dual supply FET: kzbin.info/www/bejne/rWjEaWuFec-XjJY

[@dr-mnizam]

Here is the video for dual supply FET: kzbin.info/www/bejne/rWjEaWuFec-XjJY

[@jasonbentley439]

10MEG resistor is a pull-up resistor. Since the gate has no path to ground for DC you can think of it as an open circuit, where the gate gets pulled up to Vd

[@cxk6293]

Because there's no current into the gate, so no current in the path. Then Vg and Vd must have the same potential, according to ohm's law.

[@Emma-dd1fc]

What really is the Va? I dont see where that is or what it means 😢

[@Emma-dd1fc]

I think it's like lambda = 0.02?

[@user-tf1ef3cc5e]

inverse of lamda@@Emma-dd1fc

[@ds4056]

@@Emma-dd1fc Va = 1/lambda

[@phengyang2639]

Va is the Early voltage. Analyzing the ID and VDE characteristic graph, the point of intersection from all the relationship curves correspond to some Early trans-conductance which is ID/VA where VA is the value of VDE at the point of intersection.