Plotting the Transfer Characteristic of a JFET

RE: Plotting the Transfer Characteristic of a JFET

Jan Cumps — Fri, 05 Jun 2020 13:50:11 GMT

I keep returning to these blog posts. With the shopping cart i won for the Photonics contest, I ordered 5 N-channel and 5 P-channel jfets.
Time to play with discrete components again.

RE: Plotting the Transfer Characteristic of a JFET

jc2048 — Thu, 09 Jan 2020 22:17:55 GMT

I have a bag with nine BF256B JFETs left in it, so I tested them all to get an idea of the spread of

values we might see. Here are all nine curves composited together with Gimp (there really are nine traces

there, some of them have identical curves).

[View:/resized-image/__size/480x234/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-6831ff29-f16f-4cf7-8a14-3a7a358b4287/contentimage_5F00_207775.png:480:234]

The zero-volt currents range from just over 8mA to about 11mA and the cut-off voltage from somewhere

around -2.5V to just over -3V. Something I hadn't appreciated was that the two relate in the way that

they do.

RE: Plotting the Transfer Characteristic of a JFET

dubbie — Thu, 09 Jan 2020 20:39:17 GMT

A very nice Blog, it reminds me of things I did when I started University. So long ago!

Dubbie

RE: Plotting the Transfer Characteristic of a JFET

Jan Cumps — Thu, 09 Jan 2020 19:10:01 GMT

Apart from the whole exercise, I find that each of the separate blocks in the test gig are little gems.

The way to create that reset, lifting the level in the integrator, re-referencing the output to ground level.

Simple but sweet solutions. It is always nice to find some of those in a blog, an application note, a book, a schematic.

RE: Plotting the Transfer Characteristic of a JFET

three-phase — Wed, 08 Jan 2020 20:06:53 GMT

Very interesting blog to read, thanks for posting.

Kind regards

RE: Plotting the Transfer Characteristic of a JFET

genebren — Wed, 08 Jan 2020 18:14:22 GMT

Another nice blog on FETs. Thanks for sharing.

RE: Plotting the Transfer Characteristic of a JFET

fmilburn — Wed, 08 Jan 2020 17:44:01 GMT

I am learning a lot from these. Thanks...

RE: Plotting the Transfer Characteristic of a JFET

dougw — Wed, 08 Jan 2020 14:42:43 GMT

I really like the content you generate.