#### narayani

##### Advanced Member level 4

Dear Friends,

In attachment, I have shown two Small Signal Equivalent Models of MOSFET for finding out Vgs.

In First Small Signal Equivalent Model of MOSFET, I have found out Vgs = Vg= (Vin R1//R2)/(Rg+R1//R2), because R1//R2 parallel with the Vin and Rg. Using Voltage divider, I found Vgs=Vg=(Vin R1//R2)/(Rg+R1//R2).

In Second Small Signal Equivalent Model of MOSFET shown in the attachment, I need to find out Vgs. In the Second Small Signal Equivalent Model of MOSFET shown in the attachment, I have removed the R1//R2 for my own circuit. What is the Vgs equation for the Second Small Signal Equivalent Model of MOSFET, when R1//R2 is not Parallel with the Vin and Rg (source generator resistance).

Can you help me to find out Vgs equation for Second Small Equivalent Circuit shown in the attachment, when R1// R2 are not present in the SSM of MOSFET.

In attachment, I have shown two Small Signal Equivalent Models of MOSFET for finding out Vgs.

In First Small Signal Equivalent Model of MOSFET, I have found out Vgs = Vg= (Vin R1//R2)/(Rg+R1//R2), because R1//R2 parallel with the Vin and Rg. Using Voltage divider, I found Vgs=Vg=(Vin R1//R2)/(Rg+R1//R2).

In Second Small Signal Equivalent Model of MOSFET shown in the attachment, I need to find out Vgs. In the Second Small Signal Equivalent Model of MOSFET shown in the attachment, I have removed the R1//R2 for my own circuit. What is the Vgs equation for the Second Small Signal Equivalent Model of MOSFET, when R1//R2 is not Parallel with the Vin and Rg (source generator resistance).

Can you help me to find out Vgs equation for Second Small Equivalent Circuit shown in the attachment, when R1// R2 are not present in the SSM of MOSFET.