Does anybody have a line on MOSFETs that aren't internally set up with the substrate connected to the source? It seems odd that so many mosfets are configured that way. Why not allow the flexibility of connecting the substrate directly to ground, and having the source pin possible connected elsewhere? Especially when it's in a package with 4 pins!

 

In the past there were many but today the only 2 available are
SMD devices:

MOSFET with separate substrate connection types in production:
The N-channel BSS83 of NXP and the P-channel
MIC94030/31/50/51 series of Micrel.
I never found any other...


You may have a look at this discussion:

http://www.electronicskb.com/Uwe/Forum.aspx/design/5010/Have-you-seen-this-MOSFET

 

I have also looked quite a lot for enhancement FETs with separate substrate pins and only found those same ones. It's so good to get expertise from many people on this board.

Plenty of depletion-mode FETs have separate substrate pins. Why is that?

 

I'm currently looking for a small signal N-channel depletion mode MOSFET with separate substrate pin, but have found none so far. Do you guys know how to find one? Most online part catalogues won't even let you filter enhancement/depletion mode when searching, let alone filter exotic features such as a separate substrate connection.