by SeaMonkey » Thu May 29, 2008 1:59 am
Nick,
Very good suggestion.
Kevin,
The 8 nF gate capacitance is unique to that particular HexFet.
The 6 Ampere pulse requirement (for some very high power MosFets up to 9 Amperes) is the minimum recommended by circuit designers to assure very fast Turn On and Turn Off. The faster the HexFet is able to go to Full On when pulling a heavy current, the less heat will be developed as wasted power. And the same holds true for turning off; the faster it is able to Turn Off the less heat will be developed as wasted power.
The Turn On and Turn Off speed of the HexFet is very much dependent upon the ability of the gate driver circuit to charge the gate capacitance as quickly as possible for fast turn on, and later to discharge the gate capacitance as quickly as possible for fast turn off.
Therefore, the best driver circuits are those that can both "source" gate capacitor current for charge, and "sink" gate capacitor current for discharge.
For a pretty good tutorial "right click" and "save target as" to your preferred folder/subdirectory, then view it with your PDF viewer.