2SK301 as replacement for 2SK170?

[ChrisRT]

2SK301 as alternative to 2SK170?

I have some 2SK301 jfets by Matsushita (Panasonic), datasheet attached. Class R, 5 to 12 mA IDSS. Would they be suitable for use in a unity gain buffer like the Pass B1?

There are differences in electrical characteristics compared to 2SK170, but I don't know how significant these differences are. For example, gm (Yfs) is lower than the 2SK170 - would this mean more noise at unity gain? The noise figure (NF) is low, but is only given at 100Hz, not 1kHz as for the 2SK170.

I would appreciate some advice, not being knowledgeable on jfets. If I am comparing chalk with cheese, I will assign them back to the drawer where they have lain for many years.

Sorry, I should have said "alternative", not "replacement" in original title, i.e. to use in a new circuit.

 

[jean-paul]

Hi I have at least 150 pieces 2SK170BL waiting for a new owner.

 

[ChrisRT]

Thanks for offer, but I already have some 2SK170 - I should have said "alternative", not "replacement". Title of original post edited.

 

[franzm]

The noise figure (NF) is low, but is only given at 100Hz, not 1kHz as for the 2SK170.

And for Rg=100k.

 

[EUVL]

> Would they be suitable for use in a unity gain buffer like the Pass B1?

If you would accept 4x higher output impedance (~133R), yes.


Patrick

 

[davidsrsb]

The noise figure (NF) is low, but is only given at 100Hz, not 1kHz as for the 2SK170.
[/B]

100Hz is good. The noise always goes up below some low frequency knee and too many parts hide this by specifying noise at 1kHz or higher.

 

[ChrisRT]

Thank you to all for your help. I can put these jfets to good use now.