It "seems" to run OK without the source referencing resistor. You'd
expect the sources to sit towards the most negative rail when off, as
the normally biased MOSFET applies only leakage load but the reverse
biased MOSFET appears as a forward biased diode. When V1 is +ve wrt
ground the sources would be thus slightly above ground and if V1 is
-ve wrt ground then sources are close to -V1. A gate-source clamp
zener pair (back to back ) may be needed to protect FETs against >
Vgsmax drive.

I'd be slightly nervous about M3 connecting gates hard to ground - I'd
consider a series gate resistor. But logic says it's OK as is :-).



           Russell
--=20
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