SST108 or SST113 (N JFET) replacement?

[AndersG]

Used in a low-power psu:
http://focus.ti.com/lit/an/slua016/slua016.pdf

I assume it is not very critical? Would a 2Sk170 do? The circuit will
regulate 3.7V from 9-16V DC.

 

[Phil Allison]

"AndersG"

Used in a low-power psu:
http://focus.ti.com/lit/an/slua016/slua016.pdf

I assume it is not very critical? Would a 2Sk170 do?

** An SST108 is a Nch switching mosfet.

The 2SK170 is a low noise Nch junction fet.

Similar as chalk and cheese.




...... Phil

 

[Phil Allison]

"Phil Allison"


" An SST108 is a Nch switching mosfet."


** My error - it IS a JFET.

The 2SK170 is a low noise Nch junction fet.

** Might be OK.

Strange choice but - since that is a special low noise type for audio.


........ Phil

 

[AndersG]

 Strange choice but -  since that is a special low noise type for audio.

.......  Phil

Well, I went by what my favourite distributor had in stock and they
had just two N-channel J-FETs in their catalogue. I could probably
order something from digikey or farnell, but the delivery costs tend
to be prohibitive for just a few components. Also the SST's are SMD
devices which I hate för lab work. OK so is the bq2018 that they will
be connected to, but I managed to solder that to a SOIC to DIP adapter.