Is there a simple way of find a complementary pair of a n-mosfet?

[tca]

Is there a simple way of find a complementary pair of a n-mosfet, besides harvesting all the datasheets? For instance, what is the complementary pair (p fet) of the MPF102? J201?

Thanks.

P.S.
The same applies for BJT,of course.

[Kesh]

aren't they jfets?

you could use the cross reference search at alltransistors.com

type in your transistor, press equivalent transistors, then change the search entry from npn to pnp or what have you.
.
however that site isn't so great on fets, and also i tried to do this and it didn't often turn up obvious bjt complements.

[tca]

aren't they jfets?

you could use the cross reference search at alltransistors.com

Yes they are.

Thanks for the ref.

Cheers.

[R.G.]

The only good way is to look at the datasheets and see if the maker says that they make a complement.

Complementar-ity is fairly complex at the device level. They had to at least be trying to make them any good. 

On the other hand, there are some dual complementary devices in small-signal, although mostly SMD.

[tca]

Thank for your reply R. G.

I'm looking for is a simple way of finding, for example, a p-jfet that has the same Vth voltage as the MPF102 and other specs. I can look at the TINA-TI library and look for one that works. It has a very long list of devices. It is very time consuming searching by hand for some complementarity between devices. A simple table with one device per row with the correspondent specs would be great. I don't know if one could export that library to some text file. The alltransistors.com is a good approach but I would like to read the database directly and not with a crappy search tool.

Thanks again.

[R.G.]

For being complementary, you need at least the same Vth and the same transconductance (amps per volt or Yfs).

MOSFETs and JFETs in particular have widely variable Vth and Vgsoff, as well as varying Yfs, so getting a pair of complementary devices will require some selection even within the nominally proper complementary types. That being said, picking devices with the right ranges to start with is a good thing.