Super duper hype fast FET driver?

[Joerg]

I'm just proving that Phil's statement is false. There is no argueing
about that. There is wrong everywhere but the way the church tries to
cover things up is beyond sickening.

Visit a Lutheran church some day

 

[Joerg]

Well, if you want to see unhappy women you should go to the red-light
district. However, your information is a bit outdated. Many laws and
regulations have been put in effect to minimize the possibility of
human trafficking and enslavement. It is very difficult to get a
permit to open a sex-club (aka massage salon). Even the well known
Yab-Yum has been closed down by the local authorities because there
where rumours the owners had ties with the criminal circuit.

Outdated? From what I have heard they have discovered a new source of
"revenue" and are now taxing the redlight districts:

http://www.breitbart.com/article.php?id=D9KMSBS81&show_article=1

 

[Joerg]

Joerg wrote:

[...abortion talks...]

IMHO they condoned murder, plain and simple. "Oh, you
in there, you may have a heartbeat but you are too small so we have
deemed you unworthy of being called a human being". It's sickening.

A person does not have a right for a body of another person. Mother
provides her body as a favor.

The mother made the choice of conceiving and with that come certain
obligations. One is to protect the unborn. Or do you think it would also
be perfectly ok for a pregnant woman to drink lots of alcohol and smoke?

 

[Nico Coesel]

Outdated? From what I have heard they have discovered a new source of
"revenue" and are now taxing the redlight districts:

http://www.breitbart.com/article.php?id=D9KMSBS81&show_article=1

Yup. Its a legal profession and people make money so they have to pay
tax and charge VAT. OTOH they can deduct expenses like condoms and
breast implants

 

[Joerg]

it's a job/business, why shouldn't they pay tax like everyone else?

So we look the other way when the question regarding the residency
permit comes up?

at least it is legal and regulated, so there's hope those who work
there
do it of their own free will

just like drugs prostitution won't go aways just because you ban it,
it
just means criminals will make money providing it, with no regulation
what so ever

Oh yeah, if we give up fighting it we just make it legal. Sorry, but you
will not convince me of that. I have lived in the Netherlands for about
6 years and seen the sad aftermath of that. Including some funerals.

 

[Nico Coesel]

Makes no sense. Equipment is cheap, and people are expensive.

Indeed. The most succesfull companies I worked for never cut on
measuring equipment.

I buy as much equipment as I (financially) can. Even though I use some
of my equipment less than once a year its still worth it because of
the time saved.

 

[Joerg]

Joerg wrote:

[...abortion talks...]


IMHO they condoned murder, plain and simple. "Oh, you
in there, you may have a heartbeat but you are too small so we have
deemed you unworthy of being called a human being". It's sickening.

A person does not have a right for a body of another person. Mother
provides her body as a favor.

The mother made the choice of conceiving and with that come certain
obligations.

No. That was just carelessness.

How does that justify killing the unborn?

One is to protect the unborn. Or do you think it would also

It's not OK for anyone to enforce his moral on anybody else. Especially
if this moral is "because my invisible friend said so". BTW, how about
you pay your money to that woman for not doing the abortion, and then
you raising her kid?

She certainly does not deserve to be paid for that. What moral would
that instill?

As for adoption of unwanted babies, we have tried exactly that. Were
deemed "too old" :-( ... There are tons and tons of people who would do
that right now. But lots of roadblocks are put up.

 

[Joerg]

There are several old-line PNP saturated switches that are gold-
doped. I don't remember the part numbers off hand, but they're in the
old Nat'l Semi transistor book. 2n4209, maybe?

* DROOL *

Anyone aware of one that's still made, and small?

They're pretty fast, ~1 or 2 nS edges IIRC, but not saturating them is
better still.


I measured some GHz rf transistors for a pulse application a couple
decades ago. They're VERY slow if you let them saturate--don't let
them!--but scream if you don't.

The old-fashioned brute-force way was a long-tailed NPN with a vicious
L-R pull-up (or current source) collector load.

When you break the 1nsec barrier all those measures are off-limits.
Everything must be shorter than 1/10", impedance-controlled, and zero
nanohenries. All it takes is a wee bouncy-bounce into saturation and
game's over.

 

[Nico Coesel]

The Pope is just a CEO of the Catholic Church, Inc.

Not really. Way too old. The book 'Il Principe' by Machiavelli gives
an interesting insight in the politics in Italy around 1500. At that
time the Pope was a warlord and the church just invented how to make
money by charging people for not visiting the church and other
'taxes'.

Life after death is another way for not paying the bills. The efficient
doctrine should produce the results now, here and for real.

I told my grandfather to send a postcard if there is an afterlife. So
far the mailbox has been empty :-(

 

[Joerg]

of course not, why should it be any different than if they were
working
cleaning hotelrooms, picking strawberries or something else? if they
work
they should pay tax and have the permit to live and work in that
country

I have heard they are simply issued some sort of registration pass.

do you think a ban would fix that?

Yes. I have lived in countries with bans and without. With bans there
were less people who fried their brains via drugs and less durg-related
funerals. I prefer that.

 

[Joerg]

Fairchild refers to MMBT4209 in their cross-reference .PDF, if that's
any kind of clue.

But that one is unobtanium :-(

Oh this was well under 1nS--that was the whole idea. The application
needed a <500pS pulse. When signal paths are short, ordinary SMD
parts are surprisingly close to ideal.

How did you keep the PNP out of saturation? Or did you still have some
of those rare doped ones?

I should've mentioned these particulars were PNP rf transistors, too,
in addition to measuring NPNs.

I had a 12Ghz sampling digital storage 'scope for recording waveforms,
all waveforms being recorded manually with my 10 digits . (I later
made an interface to drive the 'scope's X and digitize the Y output at
the computer.)(None of that works any more, no thanks to Bill.)

It might be surprisingly easy to get that going again, depending on the
ADC sampling rate needed it could be as simple as one of the cheap uC
eval kits. Those comes with USB nowadays.

 

[Joerg]

Oh, here's what they're calling it these days:
http://www.fairchildsemi.com/ds/MM/MMBT3640.pdf

Don't believe the timing specs, those are absurd. You have to drive
the ever-lovin'-snot out of it, but I've gotten its MMBT2369 brother
to switch an order of magnitude faster than those specs.

Thanks. Although storage and other times look really ghastly. I'll have
to try it but I don't quite see how to get that down to a nanosecond or
less.

The 2369 held true to it's data. When driving the living daylights out
of it it'll switch much faster but there was always that small dreaded
storage time of 10nsec or so.

It's still better to not saturate them. Even a simple b-c schottky
makes a world of difference. I think I drove my test samples with
74ACxx logic, series resistor, || a few pF, Vdd=+5v.

74AC is too slow for my case. How did you keep it out of saturation? The
old Schottky Baker clamp usually doesn't work on those. A two-diode
Baker makes it all sluggish, too much total inductance in the drive.

 

[Joerg]

[snip]
Now if someone had the opposite sex of the 2N7002 or a PNP with 15V+ and
no "saturation hold" that would be great. The BSS84 and it's siblings
ain't that hot.
If you find a useful complement to the 2N7002 please let me know. Thanks!

Oh I will. But don't hold your breath :-(

It's easy if you're not looking for sub-ns edges. We use

FDV302 SOT23 logic-level drive

BSS83 SOT23 gp gumdrop

NDT2955 SOT223 for more power

These all run around 25 cents each, as opposed to a 2N7002 at 3 cents.

The n-ch FDV301, complement to the 302, is only 10 cents. Holes must
cost more than electrons.

I'll test them for switching speed, eventually.

Careful, the BSS83P (the P-channel version) has and end-of-life notice
on Mouser. They have about 17,000 left, maybe time for hoarding those?

http://www.mouser.com/search/Produc...c9Nlz4g==&amp;cm_mmc=findchips-_-na-_-na-_-na

 

[Joerg]

Joerg wrote:
Vladimir Vassilevsky wrote:
Joerg wrote:
[...abortion talks...]
IMHO they condoned murder, plain and simple. "Oh, you
in there, you may have a heartbeat but you are too small so we have
deemed you unworthy of being called a human being". It's sickening.
A person does not have a right for a body of another person. Mother
provides her body as a favor.
The mother made the choice of conceiving and with that come certain
obligations.
No. That was just carelessness.

How does that justify killing the unborn?

One is to protect the unborn. Or do you think it would also
be perfectly ok for a pregnant woman to drink lots of alcohol and smoke?
It's not OK for anyone to enforce his moral on anybody else. Especially
if this moral is "because my invisible friend said so". BTW, how about
you pay your money to that woman for not doing the abortion, and then
you raising her kid?

She certainly does not deserve to be paid for that. What moral would
that instill?

As for adoption of unwanted babies, we have tried exactly that. Were
deemed "too old" :-( ... There are tons and tons of people who would do
that right now. But lots of roadblocks are put up.

it does seem odd that for adoption you basically have to be mr and
mrs
perfect parent, but for artificial insemination and such there's no
questions
asked

but I guess it does give come some confidence to those who put a baby
up for adoption

That I understand though. And except for being well over 30 we were Mr
and Mrs Perfect. Financially secure, home owners, no court convictions,
even clean driving records. But, too old.

 

[Joerg]

I don't think you'll get it under 1nS--I chimed in here where you were
asking for a gold-doped PNP in general. I didn't me to imply it's
going to meet your "sub-nS" in both directions requirement-its
capacitances are too high. I don't remember getting it that fast
either.

Yeah, I'll have to sledge-hammer a capacitance around anyhow. Requires
at least an amp to do that.

Sub-nS edges, measured. That's too slow?

I meant loaded down with the gate capacitance of a FET and such. That's
when AC runs out of steam.

The fastest way is to use an emitter current sink that doesn't allow
the collector to swing the load far enough to saturate the BJT.

Slightly slower is a good schottky, c-b. I think I used microwave
diodes. Another incremental improvement: the drive waveform had a big
initial current pulse, then starved the BJT d.c. so it'd turn off
faster.

I'll have to look into the emitter sink. The current spike is something
I did a lot but sometimes when I overdid it ... *PHUT* ... gone.

Change diodes! Or bypass them with good caps. A schottky c-b and a
slow trr diode in series could be interesting too, using the diode's
Qrr to yank the transistor off.

Capacitance c-b has to be extraordinarily low--Miller really kills it.

In my case Miller might not be too bad because I only need to swing 12V
or so.

 

[Joerg]

[email protected] wrote:

[...]

74AC is too slow for my case. How did you keep it out of saturation? The
old Schottky Baker clamp usually doesn't work on those. A two-diode
Baker makes it all sluggish, too much total inductance in the drive.

A 74ACT octal buffer makes a damned fine high-speed output driver or
fet gate driver. Use 4 or better all 8 sections in parallel.

Can it rival the NL37 series? The advantage would be that those come in
octals. In the old days I have sometimes soldered several on top of each
other but only in experiments. I know that was naughty but it did drive
the big pulser (the super expensive lab grade driver box had croaked).
It was 74AC though.

 

[Joerg]

I was thinking, some years ago, about stacking cmos gates to get more
voltage swing. Imagine, say, one 74ACT240 type buffer, all 8 sections
in parallel, driving the ground pin of a second one.

I was seriously thinking about doing such a bootstrap ride. But it'll
add too much inductance to the whole game, more so than good magnetics.

 

[Joerg]

There was a hiss, a kaboom and then a clean-up on Otis Street.

http://www.boston.com/news/local/massachusetts/gallery/asbestos?pg=3

Oh wait, wrong city

But seriously, that stuff does work. You need a higher voltage source
and a TL431 style shunt for the one riding up. And of course a gate
drive transformer to drive it, probably would have worked with a cap,
too. Back in the early ultrasound days we tried a lot of such tricks
because we had to cram umpteen pulsers onto a board, cost was an issue,
and FETs were fairly poor and simply didn't work well with 6V or so in
drive amplitude.

Later someone tried it with non-CMOS logic. Forgot which one, ABT or so.
The lid on one of the chips flew off, probably latched up. I was
surprised the substrate paths on the CMOS parts held up.

This was all 8-10nsec stuff and it was just about drive oomph and
amplitude. Really, really slow compared to what I need now.

 

[Nico Coesel]

Watch out for them. One day "friends" will come over and bring some
other stuff. "Hey, try this, gives you a much better buzz". From there
it'll all be downhill, and fast.

I think they already kicked that sort of friends out

Maybe their parents are not competent enough? It's sad. Reason I brought
it up and will never be for free drug use are all tthe stuff I witnessed
while living in the Netherlands. People whove fried their brains out and
all that. But the worst was the son of a woman in her 50's. One day she
got the call, that they found his bloated body in a canal in Amsterdam.

Well, if I see how American teenagers behave at places like Fort
Lauderdale... I doubt things are much different. I'm sure it is
possible to buy any kind of drugs no matter where you are.

He should read the bible again. It clearly spells out what is sin and
what isn't. And that we have forgiveness if only we ask for it. Yup,
also for the gal who had an abortion done years ago. But that doesn't
mean it wasn't a sin.

Well, a lot is a matter of interpretation. But you should be aware
that NL priests are also very progressive and do not always follow the
rules set by Rome. There will never be a 'Dutch' pope

That is because they do not properly recognize Jesus and the New Testament.

To me different religion = different set of rules.

I sure hope nobody will ever muck around with it. It is God's word and
not supposed to be "updated" by us.

Okay, you may call it re-interpreted. I guess there are a lot of
appendices already for cases where science came up with facts which do
not concur with the contents c.q. previous interpretation of the
bible.

They had similar issues to deal with. Read about Paul's "thorn in the
side" and about his eyesight failing. Yet he never ever thought about
ending his life. Remember Bonhoeffer? Cyanide pills were handed out in

No, but that probably has to do with me not being German

his group in case the Nazis would catch and torture them. He refused to
carry a cyanide pill.

Well, some people kill themselves for less. Someone I used to know had
everything going well for him. He was about to get married, started to
get his life back together and he still found it necessary to step in
front of a train after taking sleeping pills didn't work. Everyone has
his/her own limit.

No, they did not. IMHO they condoned murder, plain and simple. "Oh, you
in there, you may have a heartbeat but you are too small so we have
deemed you unworthy of being called a human being". It's sickening.

I agree its a slippery slope and I hope I never have to face such a
decision. I can understand that it is an option for some people. If
there really is no-one to care for the child then maybe its better off
not being born. But that really should be the last option and I doubt
it is really necessary. There are so many couples who cannot have
children of their own or people who are willing to take care of an
extra kid. We actually took care of someone else's child for a while
knowing it could be 'permanent' but in the end it didn't.

There is an interesting movie on the subject:
http://www.imdb.com/title/tt0467406/

 

[[email protected]]

John Larkin wrote:
[email protected] wrote:

[email protected] wrote:

[...]

http://www.kexin.com.cn/pdf/KC846S.pdf
No useful specs.

That is normal with many Asian suppliers, got to get used to it and test
a lot for yourself. You can sometimes obtain additional data from them
but sometimes you'd have to be married to the CEO's cousin's daughter or
something like that.
"Test a lot?" What does that tell me? It went against my grain to use a
green LED (GaN) at 3.3V. "Because one works..." Well, at least if the next
lot doesn't work we'll know.

I didn't mean a lot as in production lot, but as in "a lot of testing"

Meaning some of the properties have to be measure. In some designs that
is the only way to succeed because there are no parts that can
"formally" do what you need them to do.


http://www.rohm.com/products/discrete/transistor/complex/#03
"Very small package with two transistors."

All those aren't fast though.
Me? I don't need fast. ;-)

Lucky you

Almost all my stuff is RF nowadays.
We buy modules for all that stuff. I wouldn't attempt it with the shoestring
capital budget we're on (we're down a scope and it doesn't appear that they're
going to even replace it).

A scope? That's scary. I hope that doesn't mean any bad news. You can
nowadays get a lotta scope for $1-2k.
Or a Rigol, for $350.

That may be bit skimpy. I often find myself debugging and finding things
on the digital side, where everyone was 110% sure it couldn't possibly
be a software issue. That's mostly SPI and other serial buses where 2ch
won't really work. Also, I found that 100MHz BW ain't enough. Glitches
in systems where a 8051 screams along at 80MHz or so are specterally
above that.

That's been my point when management (and the other engineer) suggest that
100MHz is enough. Gotta have at least 3X, 5x is better.

No need for 3x or 5x here. I have a 200MHz BW scope with 1GSPS realtime,
cost me about $1800 including tax. If things get any faster then I can
usually make them repetitive, at least on a temporary basis, and fire up
the old HP. That only has a 40MHz converter but a very good one and its
BW is 1GHz.

It's just so weird to see the words "8051 screams along" run together like
that. ;-)

Like this

I am not a gigital guy but AFAIK there aren't too many other uCs that
you can clock at 100MHz.

We use an NXP ARM LPC1754, and it can clock at 100 MHz. Since it's a
register-rich 32-bit RISC thing, it really screams. We buy them
programmed with our code and laser marked from Arrow for $4.75 each.

The last board I designed really screams too. It's one of those 32MHz 8051
things. ;-) At least it's a SiLabs part.

We're also using LPC3250s, which clock at 270 MHz or some such, around
$8.

BTW, I had a scan done on the board with the 13 ADI Iso-Power (180 and 300MHz
chip-scale switching regulators). It looks pretty quiet! I'll take a closer
look tomorrow but the worst stuff has at least a 20dB margin (maybe 30). It's
odd because the worst frequencies are way too low to be the ADI things. I'll
have to look closer.

The bad the thing I went up to test failed conducted emissions. The
stupid wall wart evidently doesn't like to be unloaded (the thing draws <10mA
at 5V). We use it elsewhere and it's always passed. :-(