pbilling
Newbie level 3
While going through Razavi's Book i see that for a Diode connected NMOS the impedance seen from source decreases when considering the body effect. I understand the mathematical analysis but i am little confused understanding it intuitively.
* small signal body effect current is modeled as Gmb*Vbs. Vbs = Vb - Vs (Vb is grounded ) so it is -> Gmb*-Vs
* we know that as Vs increases Vth will increase(extra depletion ions added). Also Vgs decreases , And the current will decrease(Id).
If the current decreases how is the impedance decreasing?
I think i am mixing the large and small signal. Can someone please help me understand this?
* small signal body effect current is modeled as Gmb*Vbs. Vbs = Vb - Vs (Vb is grounded ) so it is -> Gmb*-Vs
* we know that as Vs increases Vth will increase(extra depletion ions added). Also Vgs decreases , And the current will decrease(Id).
If the current decreases how is the impedance decreasing?
I think i am mixing the large and small signal. Can someone please help me understand this?