MOSFET transistor equations
Here we explain MOSFET transistor equations and we know MOSFET is a multiple junction semiconductor device, multiple parameters make enormous equations based on MOSFET.
So in this post, we include some of the important MOSFET transistor equations.
N-MOSFET equations
Cut-off region
- Drain current – iD= 0
- Gate to source voltage = VGS < VTN
Linear region
- Drain current – Id= Kn (W/L). (VGS – VTN)VDS
- Gate to Source voltage = VGS > VTN
- Gate to drain voltage = VGD > VTN
Saturation region
- Drain current – Id= ½ Kn (W/L). (VGS – VTN)2
- Gate to source voltage = VGS > VTN
- Gate to drain voltage = VGS < VTN
Threshold voltage equation
VTN = VTO + ℽ(√2ϕf + VSB – √2ϕf)
Transconductance equation
gm=2ID/ VGS – VTN
Maximum operating frequency equation
fT= gm/ 2π(Cgs + Cgd)
P-MOSFET equations
Cutoff region
- Drain current – iD= 0
- Gate to source voltage = VGS > VTP
Linear region
- Drain current – iD= Kp (W/L) . (VGS – VTP) VDS
- Gate to source voltage = VGS < VTN
- Gate to drain voltage = VGD < VTN
Saturation region
- Drain current – iD= ½ Kp (W/L) . (VGS – VTP)2 . (1+λ . VDS)
- Gate to source voltage = VGS < VTP
- Gate to drain voltage = VGD > VTP
Threshold voltage equation
VTP = VTO + ℽ (√2ϕf + |VSB| – √2ϕf)
Transconductance of equation
gm=2ID/ VGS – VTP
Maximum operating frequency
FT = gm/ 2π(Cgs + Cgd)