>Can anyone recommend a readily available power MOSFET with low on
>resistance (<0.03 ohm) when directly driven from a PIC output (5 volt
>supply). I ordered what looked like a promising device from Digi-key,
>only to find out that it was "vapor-ware". Current capacity required
>is modest, but must have low Ron.  Thanks
>
>jk

If you can get +12V somewhere you can switch MOSFETS with the PIC.  Just
connect the PIC output pin to the MOSFET gate and pull the gate to 12V with
a 10k or so resistor, larger means slower response when turning on.  You
may want to put a small, 500 ohms or so, between the PIC and MOSFET gate.
This is to limit the short current spikes that may occur when discharging
the gate capacitance of the MOSFET.  Now you can turn the MOSFET on my
making the PIC pin an INPUT, this should put the pin into a high impedance
state, letting the MOSFET gate be pulled high by the 10k resistor.  To turn
the MOSFET off, just make the pin an output and drive it low, pulling the
MOSFET gate to ground.

Hope this help,
-shane

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Shane Trent                    Diamond Deposition and Analysis Laboratory
NCSU Box 7919                              Internet: sdtrent@mte.ncsu.edu
1001 Capability Drive                            Voice:    (919) 515-7083
Raleigh, NC  27695-7919                          Fax:      (919) 515-6037
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