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orbanp1 · 21st Apr 2021, 12:27 pm

Hi Ron,

Regarding swapping of terminals of a JFET.
It is not how Tek uses a JFET, but it is the structure of the FET that determines if the S and D terminals can be swapped.
The FETs where the terminals can be interchanged do have symmetrical structure.
The 4416 FET datasheets do not mention that this is the case.
The J310 JFET datasheet e.g. specifically mentions that the Source and Drain are interchangeable.
I am not suggesting that the J310 is a suitable replacement, I did not check, just bringing it up as an example of a symmetrical JFET.

Regards, Peter

21st Apr 2021, 12:27 pm	#7
orbanp1 Heptode Join Date: Nov 2009 Location: London, Ontario, Canada Posts: 675	Re: Tektronix P6201 FET Probe repair Hi Ron, Regarding swapping of terminals of a JFET. It is not how Tek uses a JFET, but it is the structure of the FET that determines if the S and D terminals can be swapped. The FETs where the terminals can be interchanged do have symmetrical structure. The 4416 FET datasheets do not mention that this is the case. The J310 JFET datasheet e.g. specifically mentions that the Source and Drain are interchangeable. I am not suggesting that the J310 is a suitable replacement, I did not check, just bringing it up as an example of a symmetrical JFET. Regards, Peter