Because the Gate (G) input terminal of a MOSFET is insulated, the amounts of charge Q seen from the Gate are important characteristics. Figure 1.5 illustrates the definitions of gate charge characteristics.
Total gate charge Q g
The amount of charge to apply voltage (from zero to designated voltage) to gate
Gate-source charge 1 Q gs1
The amount of charge required for a MOSFET to begin to turn on (before dropping drain-source voltage)
Gate-drain charge Q gd
The amount of gate charge charged in the Miller plateau
Gate switch charge Q sw
The amount of charge stored in the gate capacitance from when the gate-source voltage has reached V th Until the end of the Miller plateau
Output charge Q oss
The definition of the gate charge amount is shown in the figure below.