AoE x-Chpaters - 1x.3 Capacitors

[Jan Panteltje]

On a sunny day (Wed, 7 Aug 2019 02:31:22 -0500) it happened "Tim Williams"
<tiwill@seventransistorlabs.com> wrote in <qiduoc$qk$1@dont-email.me>:

There's also poled (electret) capacitors, which are still pretty boutique as
far as I know, but they're out there. TDK CeraLink for example.
Temperature sensitive, although I see some rated for reflow temperature now,
without needing to be re-poled? What's up with that? Hmmm...

Thank you, did not know that, found this:
https://www.tdk-electronics.tdk.com/en/1195576/products/ceralink-presentation---overview
https://www.tdk-electronics.tdk.com/download/1195592/b0aaa3ec145bc06268d74c400bcf3f4d/ceralink-presentation.pdf

Have you tried those?

 

[John Larkin]

On Wed, 7 Aug 2019 02:31:22 -0500, "Tim Williams"
<tiwill@seventransistorlabs.com> wrote:

Hmm, thought this sent, but it seems to have gone lost.

Overall very good, to the best of my knowledge.

Fig 1x.51 -- should be Al2O3, Ta2O5?

I suppose supercaps could be broken out into a few types as well, including
those weird hybrid-ion thingies. Or further into batteries and general
electric charge-based energy storage media... haha, well, that figure would
span multiple pages, no need to go that far.

Varactors -- curious, has anyone made a MEMS variable cap yet? That would
be interesting, probably not competitive with varactors though? I digress.

Yes, MEMS variable caps and switches keep getting introduced, but
don't seem successful.


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[boB]

On Wed, 07 Aug 2019 08:27:26 -0700, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Wed, 7 Aug 2019 02:31:22 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

Hmm, thought this sent, but it seems to have gone lost.

Overall very good, to the best of my knowledge.

Fig 1x.51 -- should be Al2O3, Ta2O5?

I suppose supercaps could be broken out into a few types as well, including
those weird hybrid-ion thingies. Or further into batteries and general
electric charge-based energy storage media... haha, well, that figure would
span multiple pages, no need to go that far.

Varactors -- curious, has anyone made a MEMS variable cap yet? That would
be interesting, probably not competitive with varactors though? I digress.

Yes, MEMS variable caps and switches keep getting introduced, but
don't seem successful.

Were vacuum capacitors in there ?

 

[Phil Hobbs]

On 8/7/19 11:27 AM, John Larkin wrote:

On Wed, 7 Aug 2019 02:31:22 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

Hmm, thought this sent, but it seems to have gone lost.

Overall very good, to the best of my knowledge.

Fig 1x.51 -- should be Al2O3, Ta2O5?

I suppose supercaps could be broken out into a few types as well, including
those weird hybrid-ion thingies. Or further into batteries and general
electric charge-based energy storage media... haha, well, that figure would
span multiple pages, no need to go that far.

Varactors -- curious, has anyone made a MEMS variable cap yet? That would
be interesting, probably not competitive with varactors though? I digress.

Yes, MEMS variable caps and switches keep getting introduced, but
don't seem successful.

I wouldn't design one in, despite the attractively low capacitances. No
track record, for one thing, and too many conflicting requirements, for
another. Good processing characteristics != good operating characteristics.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Piotr Wyderski]

Winfield Hill wrote:

Please report back with comments, suggestions,
and by all means, typos and errors.

Al2O5?!

Best regards, Piotr

 

[John Larkin]

On Wed, 7 Aug 2019 13:40:28 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 8/7/19 11:27 AM, John Larkin wrote:
On Wed, 7 Aug 2019 02:31:22 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

Hmm, thought this sent, but it seems to have gone lost.

Overall very good, to the best of my knowledge.

Fig 1x.51 -- should be Al2O3, Ta2O5?

I suppose supercaps could be broken out into a few types as well, including
those weird hybrid-ion thingies. Or further into batteries and general
electric charge-based energy storage media... haha, well, that figure would
span multiple pages, no need to go that far.

Varactors -- curious, has anyone made a MEMS variable cap yet? That would
be interesting, probably not competitive with varactors though? I digress.

Yes, MEMS variable caps and switches keep getting introduced, but
don't seem successful.



I wouldn't design one in, despite the attractively low capacitances. No
track record, for one thing, and too many conflicting requirements, for
another. Good processing characteristics != good operating characteristics.

Cheers

Phil Hobbs

I think the problem with MEMS switches is that they tend to stick
closed. The proposed parts that I've seen had fabulous specs.

Varicaps are cheap and not very microphonic!

 

[Phil Hobbs]

On 8/7/19 2:37 PM, John Larkin wrote:

On Wed, 7 Aug 2019 13:40:28 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 8/7/19 11:27 AM, John Larkin wrote:
On Wed, 7 Aug 2019 02:31:22 -0500, "Tim Williams"
tiwill@seventransistorlabs.com> wrote:

Hmm, thought this sent, but it seems to have gone lost.

Overall very good, to the best of my knowledge.

Fig 1x.51 -- should be Al2O3, Ta2O5?

I suppose supercaps could be broken out into a few types as well, including
those weird hybrid-ion thingies. Or further into batteries and general
electric charge-based energy storage media... haha, well, that figure would
span multiple pages, no need to go that far.

Varactors -- curious, has anyone made a MEMS variable cap yet? That would
be interesting, probably not competitive with varactors though? I digress.

Yes, MEMS variable caps and switches keep getting introduced, but
don't seem successful.



I wouldn't design one in, despite the attractively low capacitances. No
track record, for one thing, and too many conflicting requirements, for
another. Good processing characteristics != good operating characteristics.

Cheers

Phil Hobbs

I think the problem with MEMS switches is that they tend to stick
closed. The proposed parts that I've seen had fabulous specs.

Yeah. You have to be able to make the contacts by etching or liftoff,
which makes it sort of hard to have the right contact plating for a
relay. Also of course the actuators aren't that stiff.

Varicaps are cheap and not very microphonic!

Plus you can use two back-to-back to cancel the even-order nonlinearity.
At a fixed frequency you can do pretty well on the odd orders by
adding an inductor in series and another in parallel. You resonate the
series inductor just off the high-capacitance end, and then resonate the
parallel inductor with the series combination just off the
low-capacitance end. Makes good phase shifters.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 8/7/19 4:12 AM, Jan Panteltje wrote:

On a sunny day (Wed, 7 Aug 2019 02:31:22 -0500) it happened "Tim Williams"
tiwill@seventransistorlabs.com> wrote in <qiduoc$qk$1@dont-email.me>:


There's also poled (electret) capacitors, which are still pretty boutique as
far as I know, but they're out there. TDK CeraLink for example.
Temperature sensitive, although I see some rated for reflow temperature now,
without needing to be re-poled? What's up with that? Hmmm...

Thank you, did not know that, found this:
https://www.tdk-electronics.tdk.com/en/1195576/products/ceralink-presentation---overview
https://www.tdk-electronics.tdk.com/download/1195592/b0aaa3ec145bc06268d74c400bcf3f4d/ceralink-presentation.pdf

Have you tried those?

Of course poling the cap is going to make the piezo problem much, much
worse.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Winfield Hill]

Gerhard Hoffmann wrote...

While I'm at it:
Win, what for is R3 = 2R2 in the transistor noise test
circuit Fig 8.92 of AOE3, with the jumper across it?

From the caption: "The gain-calibrating input signal is
replaced by a 0 Ω shorting plug during noise measurement."

IIRC, the fixture is capable of making effective noise
measurements below 2.2 ohms.


--
Thanks,
- Win

 

[Metabastler]

Am 05.08.2019 um 23:57 schrieb Winfield Hill:

Here's another x-Chapter DRAFT section to examine
and think about. This is 1x.3, about capacitors.
The x-Chapters are about parasitic aspects, etc.
Please report back with comments, suggestions,
and by all means, typos and errors.

https://www.dropbox.com/s/q9jn6jeplmg9ler/1x.3_Capacitors_DRAFT.pdf?dl=1

In fig. 1x.51 I missed air capacitors in the fixed section.
While rare and expensive, they are commonly used as reference standards.
Genrad Type 1404


Greetings from Germany
Henrik

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