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Old 4th May 2014, 12:41 PM   #351
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You can get huge cascode devices, or you can parallel some devices with
ballast resistors for current sharing.

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Old 4th May 2014, 12:56 PM   #352
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Nelson in this type of application would you expect a power Jfet used as a folower to
have significantly lower distortion and used as a follower the input capacitance won't be
a problem to drive ( as you mentioned in your mosfet citation 12 article )
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Old 5th May 2014, 02:22 AM   #353
aoc is offline aoc  Malaysia
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It should also help improve the open loop bandwidth if memory serves me right

Alex

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Old 5th May 2014, 02:51 AM   #354
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I don't expect that there would be any issues. As followers, almost everything
we play with is easily driven from a capacitance standpoint. The rationale
for cascoding the follower is to take dissipation off the part so that you
can bias it at high levels.

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Old 5th May 2014, 02:03 PM   #355
poynt99 is offline poynt99  Canada
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Nelson,

I believe you've also noted elsewhere that followers exhibit less distortion if ran under cascode. Is that because of the increased bias current, or lower voltage across the device?
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Old 5th May 2014, 02:16 PM   #356
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Nelson has a whole paper about this.


https://passlabs.com/articles/cascode-amp-design
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Old 10th August 2014, 04:18 AM   #357
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Default What's the Buzz - Part II

Attached is the second part in a three part series entitled "What's the Buzz?" The document and a supporting spreadsheet are included in the zip archive. I had to reduce the resolution of the pdf document to fit under the upload file size limit imposed by the forum. If you prefer slightly better resolution, email me and maybe I can arrange for the higher rez document to be available on a file uploader site.

Many of you have encouraged me throughout the more than one year it has taken me to research and write the second installment. Well! I"m glad to finally be able to push the post button and get this off my chest. It's like a good confession, it really puts the mind at ease.

Anyway, as before, this is the next step in my goal to understand why you guys like the SemiSouth JFET so much.

As before, I hope you find it both worthwhile and entertaining to read. The subject of Part III, negative feedback, is hardly a topic calculated to get the next one out in a timely manner, but your encouragement does really help.
Attached Files
File Type: zip Whats the Buzz_Part_II.zip (927.0 KB, 208 views)
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Old 10th August 2014, 05:05 AM   #358
Apogee is offline Apogee  United States
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Thumbs up Awesome!

SemiSouthfan,

I/we really appreciate you taking the time to put this together. I'm looking forward to learning from it. Part I was excellent.

I keep hoping the products will get re-released at some point. I think the demand would be there.

Thanks again,

Steve
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Last edited by Apogee; 10th August 2014 at 05:09 AM.
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Old 10th August 2014, 05:20 AM   #359
labjr is offline labjr  United States
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Good reading! Thanks
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Old 10th August 2014, 09:57 AM   #360
Zen Mod is offline Zen Mod  Serbia
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amusing and witty

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