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277Conduction and Switching Losses
8.14 Optimizing Driver Capability vis-à-vis MOSFET
Characteristics
In Figure 8.20 , we have two separate graphs. The one on the left has a fixed pull-up of
4 ohms. On the x -axis, we are therefore, in effect, varying only the pull-down. So if for
example, the x -axis is at 2, the pull-down resistor is 4 ohms/2 2 ohms. If the x -axis is
at 4, the pull-down resistor is at 4 ohms/4 1 ohm. We see that as expected, the losses
decrease as the pull-down is improved. We also see the effect of “ varying ” the threshold
voltage. So, lower threshold voltages also help lower the switching ...