Concept — Miller Plateau Voltage

V_plat: the plateau voltage that appears on V_GS during gate charging, corresponding to the region where V_DS drops rapidly (the Miller transition).

Definition (JEDEC JESD24-2)

Q_GS is defined as the charge required to charge V_GS from 0V up to the Miller plateau voltage V_plat (at a specified I_D), not merely up to V_GS(th):

$Q_{GS}=Q_{GS1}(\text{charge to }{V}_{th})+Q_{GS2}(V_{th}\to V_{plat})$

Extraction Usage

$V_{plat}=Q_{GS}/C_{gs}$. Verification: $V_{plat}$ must lie between $V_{GS(th)}$ and $V_{drive}$.

Overdrive Charge

After V_DS has dropped to V_DS(on)≈0V, V_GS charges from V_plat to V_drive, absorbing the overdrive charge:
$Q_{overdrive}=Q_G-Q_{GS}-Q_{GD}$.

Related

• non-linear-capacitance-extraction, charge-conservation-qv
• power-mosfet, gan-hemt