Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

New VFET build
New VFET build
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 23rd June 2018, 12:21 AM   #11
N101N is offline N101N
diyAudio Member
 
Join Date: May 2018
It comes down to how charge density is modulated in the semiconductor channel. The manufacturing objectives aim almost exclusively at fast switching between two distinct electrical states, where a well-defined, high on-off current ratio is of overwhelming importance, while complex signal handling is a nonissue. These applications constitute parametric irreconcilability. Insufficient frequency response extensively plaguing semiconductor amplifiers is a source of massive signal distortion. The high frequency regime is cumbersome to manage, it requires the gate length to be short that in turn ordinarily requires the gate dielectric to have substantial nonuniformities and to be a big ugly capacitor limiting frequency performance. The geometrical structure of Japanese VFETs differs from that of all other semiconductors. Conductivity is determined by the correlation between two large repulsive electrostatic forces. As the dielectric material, low density covalent (atomically bonded) silicon dioxide is used without epitaxial layer, avoiding the detrimental capacitance formed under reverse bias by the metallic gate, the extending oxide layer and the semiconductor in the unstable, ionic, ferroelectric P-N junction and in the even more metallic, wide band gap Schottky barrier. Instead, appropriate charge excitation is primarily accomplished by the technologically advanced design of the critical gate-source interface intended to reduce electrostatic shielding. The silicon dioxide dielectric layer is located between the gate electrode and the semiconducting layer, which is also located between the source and the drain electrodes. In the absence of distortive P-N junction, the source and drain electrodes are attached directly to the semiconductor that makes up the capacitive channel, the channel length defined by the thin dielectric layer rather than by the semiconducting layer. The electrodes being stacked vertically in separate layers, and the gate not being positioned between the source and drain, it is a true vertical structure. The result is small inter-electrode capacitances, wide operational frequency range, high saturation velocity, low amplification factor, low gate series resistance, high drain-source channel resistance, rigid electronic coupling, smooth transition of electronic states, preciseness and small losses in the signal formation.
  Reply With Quote
Old 23rd June 2018, 12:37 AM   #12
wintermute is offline wintermute  Australia
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
New VFET build
N101N please add some formatting to your posts, the wall of words is very hard to read.
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos
  Reply With Quote
Old 23rd June 2018, 03:04 AM   #13
N101N is offline N101N
diyAudio Member
 
Join Date: May 2018
My problem is that the subject matter cannot be properly described and understood within Classical Mechanics. However, the terms are conventionally used in other theories (Quantum Mechanics, Bond Theory, Optics) and are traceable. Thank you for accepting the statement anyway, I am sorry and will try to exercise restraint.
  Reply With Quote
Old 23rd June 2018, 03:32 AM   #14
wintermute is offline wintermute  Australia
just another
diyAudio Moderator
 
wintermute's Avatar
 
Join Date: Aug 2003
Location: Sydney
New VFET build
Some paragraphs would help a lot

That's what I meant by the wall of words, there is no break, and it makes it hard to read. I have reformatted your post in the quote below so you can see what I mean. I may not have split it exactly as you would wish to convey, but hopefully that shows you what I mean.

Tony.

Quote:
Originally Posted by N101N View Post
It comes down to how charge density is modulated in the semiconductor channel. The manufacturing objectives aim almost exclusively at fast switching between two distinct electrical states, where a well-defined, high on-off current ratio is of overwhelming importance, while complex signal handling is a nonissue.

These applications constitute parametric irreconcilability. Insufficient frequency response extensively plaguing semiconductor amplifiers is a source of massive signal distortion. The high frequency regime is cumbersome to manage, it requires the gate length to be short that in turn ordinarily requires the gate dielectric to have substantial nonuniformities and to be a big ugly capacitor limiting frequency performance.

The geometrical structure of Japanese VFETs differs from that of all other semiconductors. Conductivity is determined by the correlation between two large repulsive electrostatic forces.

As the dielectric material, low density covalent (atomically bonded) silicon dioxide is used without epitaxial layer, avoiding the detrimental capacitance formed under reverse bias by the metallic gate, the extending oxide layer and the semiconductor in the unstable, ionic, ferroelectric P-N junction and in the even more metallic, wide band gap Schottky barrier.

Instead, appropriate charge excitation is primarily accomplished by the technologically advanced design of the critical gate-source interface intended to reduce electrostatic shielding. The silicon dioxide dielectric layer is located between the gate electrode and the semiconducting layer, which is also located between the source and the drain electrodes.

In the absence of distortive P-N junction, the source and drain electrodes are attached directly to the semiconductor that makes up the capacitive channel, the channel length defined by the thin dielectric layer rather than by the semiconducting layer. The electrodes being stacked vertically in separate layers, and the gate not being positioned between the source and drain, it is a true vertical structure.

The result is small inter-electrode capacitances, wide operational frequency range, high saturation velocity, low amplification factor, low gate series resistance, high drain-source channel resistance, rigid electronic coupling, smooth transition of electronic states, preciseness and small losses in the signal formation.
__________________
Any intelligence I may appear to have is purely artificial!
Some of my photos
  Reply With Quote
Old 23rd June 2018, 05:18 AM   #15
N101N is offline N101N
diyAudio Member
 
Join Date: May 2018
Thank you for the readability boost!
  Reply With Quote
Old 2nd July 2018, 12:14 AM   #16
N101N is offline N101N
diyAudio Member
 
Join Date: May 2018
[IMG]C:\Documents and Settings\Administrator\Desktop\MOSFET.png[/IMG]

Standard MOSFET architecture showing numerous muddying layers, contacts and materials.

Inspired by the working principle of electron tube, the technical realization of VFET is indeed a remarkable achievement. Not every device sorted under the hollow label Static Induction Transistor meets the above criteria for membership in the class.

An exposition worth its salt explaining the connection between voltage-current curves and device performance in understandable language is yet to be presented. It is going to be a challenging enterprise.

The one dimensional mathematical term linearity has come to mean low signal distortion. There is nothing linear (proportional) about amplification whatsoever. Current, voltage, conductance designate a static state and become nonsensical in a dynamic context. Consisting of myriads of spontaneous ephemeral changes, a signal is neither current nor voltage.

I-V curves do not say anything about signal transfer. They have practical relevance to a single stationary operating point. The DC level shifts are actuated dynamically, mainly by the load standing in an indeterminable relation. The strong dependence on energy level and temperature randomizes all parameters. The idealized linear graphs on the paper can be considered to be tube-like, but physical performace can scarcely be tube-like. The electromagnetic field produced by vibrations in the highly dispersive, noisy, contaminated crystal lattice is quite unlike the clean, well shielded, low pressure environment produced by thermionic emission.

Frequency range is inversely related to overall energy level as frequency (velocity = distance per time) is inversely related to both charge separation distance and mass density. Due to exponential distributions, velocity drops rapidly with increasing voltage and with increasing current. That is why transistors devoted to voltage amplification are designed to operate at small currents, and that is why transistors conducting a large current exhibit poor frequency response.

The plain mass times velocity in various old and new disguises: E = mv = ma = mv² = IV = mc² = hv
If my memory serves me correctly, Descartes used it, Leibniz used it (in the form mv²) before Newton, also Maxwell and Poincaré used it before Einstein.
It is up to everyone to deem if it denotes impetus, momentum, force, power, work, energy, electricity or something else.
  Reply With Quote
Old 5th July 2018, 02:12 AM   #17
N101N is offline N101N
diyAudio Member
 
Join Date: May 2018
By the way, the Siliconix VMPXX and 2N665X series are certainly suitable for audio, especially the ones with a higher drain to source resistance and smaller capacitances (lower power handling capability), so I would not feel disappointed.
  Reply With Quote
Old 5th July 2018, 07:12 AM   #18
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
"Readability" is a bug of mine. My Mom was a newspaper editor, trained in the days before tabloid click-bait; Dad was an engineer who worked to put his thinking into words to influence bosses and customers.

I use gut-sense but also tools. I used to have a good suite of text-tools but alas. MS Word (at least my old copy) has "something". It can be exceptionally stupid so you have to see if the counts even make sense. (Note the paragraph counts!)

Flesch Ease is very easy to compute. Flesch-Kincaid Grade is easy and maybe more "accurate" for most texts; it is also scaled to the US school-grades 1-12.

Mom would want 90% of a newspaper to be readable at a 9th-grade level. Not that the readers were all drop-outs; for ease-of-reading.

The "It comes down to how charge density is modulated.." post scores as Grade 18, nominally post-graduate college. I have seen higher, but from a bunch of PhDs who were not really saying anything. "Ease" is a low 9. (It may also be "wall of words", and paragraphing helps my eyes, but does not change the computed scores, at least to MS-Word's tiny mind.)

haiqu’s post scores Grade 12, ease 56. This may be quite appropriate for technical matter with many jargon words.

Curious, I hunted for one of Stephen Hawking’s non-pop papers. WOW! Grade 6, Ease 66! It is possible Hawking or his editors "massaged" the text for computed Readability (it was hot stuff at that time), but it does not read as manipulated.

Note particularly the "Passive Sentences" scores. It is IMpossible for a computer to truly know passive from active voice. However there is a trend I agree with. For his murky topic, Hawking is marvelously active-voice. (So is haiqu, but he’s talking about his system and his feelings and thoughts.)
Attached Images
File Type: gif Readabilty-texts.gif (133.5 KB, 220 views)

Last edited by PRR; 5th July 2018 at 07:17 AM.
  Reply With Quote
Old 11th July 2018, 07:42 PM   #19
haiqu is offline haiqu  Australia
diyAudio Member
 
haiqu's Avatar
 
Join Date: Oct 2005
Location: Brisbane
Interesting stuff PRR. I was taught to separate distinct thoughts into different paragraphs for readability so it comes naturally. Observation of good writing through extensive reading also helps here.

Writing well seems to be something of a lost art.
__________________
[VK9VK] With great power comes great current squared times resistance.
I spent most of my money on fast cars, hot girls, hi-fi gear and booze. The rest I just wasted.
  Reply With Quote
Old 11th July 2018, 07:44 PM   #20
haiqu is offline haiqu  Australia
diyAudio Member
 
haiqu's Avatar
 
Join Date: Oct 2005
Location: Brisbane
Quote:
Originally Posted by N101N View Post
By the way, the Siliconix VMPXX and 2N665X series are certainly suitable for audio, especially the ones with a higher drain to source resistance and smaller capacitances (lower power handling capability), so I would not feel disappointed.
Not sure why a high D-S resistance would be desirable, except perhaps that this indicates they weren't intended for switching.

Noting that the ones I bought both have small input capacitance, they should be usable. It's a pity I didn't find some with higher power ratings though.
__________________
[VK9VK] With great power comes great current squared times resistance.
I spent most of my money on fast cars, hot girls, hi-fi gear and booze. The rest I just wasted.
  Reply With Quote

Reply


New VFET buildHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sony Vfet Illustrated build guide 6L6 Pass Labs 664 Today 12:08 AM
VFET-X (or my 1/3 40th Anniversary Sony VFET Clone) WalterW Pass Labs 177 28th April 2018 12:14 AM
IC: 2x sony vfet essentia kits, PSU PCB's, vfet part 2 PCBs and other acessories MASantos Swap Meet 7 15th April 2018 05:34 PM
FS: Matched 2SK2013, 2SJ313, IRFP240 and IRFP9240 pairs for the VFET amp build NicMac Swap Meet 4 22nd December 2016 12:54 AM
VFET PP amp juma Pass Labs 89 12th April 2014 10:26 AM


New To Site? Need Help?

All times are GMT. The time now is 09:00 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki