I'l like to hop on this tread.  I'm having a similiar, and maybe the same
problem.  I'm driving an 8X8 matrix of bicolor leds from two ports.  Since
the port pin may have to sink/source current for 8 leds I'm buffering the pin
with p- and n- channel enhancement mosfets---Zetex zvp4105a and Zetex vn10lp,
respectively.  The leds work but are dim.  The problem is that the fets don't
sat.  (I simulated the pic by tying the gates to Vdd and Vss manually).  When
I lifted the gate of the N-ch to 9V the led lit as it shoud.  I'm wondering
if I'm using the wrong units, or is there a way to saturate the channel at a
lower Vgs?

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body