miller capacitor (C
rss
). During this period, a large impulse is seen in the gate
drive current. This plateau occurs at a voltage slightly higher than the rated gate
threshold voltage and is V
TH
+ I
D
/g
m
. The value of the plateau voltage can also
be determined by using the transfer function graph provided in every MOSFET
data sheet (see Figure 3–37). For an inaccurate estimation, the threshold voltage
can be used. The MOSFET datasheets provide the graphs seen in Figure 3–37.
These capacitances cause delays in the switching performance of the
MOSFET. The drive circuits should be able to drive capacitive loads. First, the
amount of charge required to transition ...