David VanHorn <dvanhorn <at> microbrix.com> writes:

ASCII art follows (use fixed font):


DD---D S---S D---SS
      G     G
      |     |
      R1    R2
      |     |
      +--+--+
         |
         GG
 
R1, R2 must be large value (cannot be tens of ohms as usual). This implies slow
switching. Be careful of reverse voltage on the 'free' pin, as now reverse
voltage on that pin may translate into reverse voltage on the gate. Usually you
can rearrange the circuit so such things are not needed. The compound fet can
open when Vg > Vp vs. *either* DD *or* SS. This may not be what you want. Try to
look at optofets imho.

Peter P.

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