Jfet diode protection. How important is it ?

[JasonG]

Hey guys I am building this booster  http://www.aronnelson.com/gallery/v/DRAGONFLY-LAYOUTS_0/album87/JFET_BOOST.gif.html   
  I don't have any 9.1 v zeaners to throw in there. There is no Zeener in there but dont you pretty much need one with Jfets all the time?
How important are they ? I did a search but couldn't find a relvent topic.
Thanks

[soulsonic]

JFETs aren't very sensitive to static damage, so the answer is "NO".

It's MOSFETs that you have to be careful with. Anything that uses MOS kind of technology is highly sensitive to static damage. The metal oxide layer is very delicate and static can ruin it very easily.

[JasonG]

Thanks alot!

[JDoyle]

Here's a tip: while you don't need the zener, JFETs are WIDELY variable on a number of important characteristcs so I would DEFINITELY sub a 50k trim pot for R4 and adjustit until you get 4.5V (or 1/2V+) at the drain.

Good luck!

Jay Doyle

[96ecss]

Since I was bored tonight and I haven't done a layout in a few weeks I figured I'd do this one. I haven't built it but it should work fine.

http://www.aronnelson.com/gallery/v/Daves-Layouts/Dragonfly+JFet+Boost.gif.html

Dave