Super duper hype fast FET driver?

[[email protected]]

[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"

But that means you need a lot of lots! ;-)

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.

In my former life, we would specify what was needed. Sometimes it got
expensive but the groundrules for such designs was "worst case". Life is much
simpler now. ;-)

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

I don't think it's permanent bad news. I think it's more prudence, given the
Obama recession. I really can't argue much. The scope we lost was a 300MHz
model. The remaining one is only 100MHz (there is another but it's usually
tied up with firmware stuff) and they seem to think that's good enough. Of
course, I'm holding out for a MSO3034. ;-)

I really need other stuff, too. I'm going up to Atlanta for compliance
testing on a design I know will fail ESD. It was never designed to pass (the
JTAG port is exposed on an external connector) but the requirements changed at
the last minute (well, the last week). I really need an ESD gun.

Maybe, after Obama gets the boot. ...or I retire again. ;-)

 

[[email protected]]

[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.

[...]

Starting at a Ghz bw ?

We don't need anything like that. Who looks at the carrier? ;-)

 

[Jamie]

Looking at the 2N7002 data sheets, one would never expect the sorts of
speeds I'm seeing. All you can do is get some parts and try them.

The ones that switch fast seem to have low Cg, modest Rds-on, and peak
drain current ratings under an amp (which doesn't stop me from going
above an amp.)

I recall Win Hill getting kilovolt edges in a couple of ns from fets
that, from the data sheets, shouldn't do that.

John

Good thing you have some Cg there to help clamp those kilovolt
edges...Assuming they were short to begin with.

Jamie

 

[Jamie]

[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.

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.

[...]

Starting at a Ghz bw ?

Jamie

 

[Joerg]

[...]

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.

[...]

Starting at a Ghz bw ?

Jamie

You can get a Tek 11801C and an SD14 plugin (3 GHz, with built-in FET
probes) for $1k total on eBay. Of course that's a stroboscopic sampling
scope and not a single-shot digitizing one, but it's beautiful for
repetitive signals.

Yup. It pays to not always insist on the latest, best, tallest, most
expensive gold-plated gear. I do have a GHz BW scope here but it is
repetitive sampling, HP from the early 90's. Good enough for work and I
do a very wide variety of projects, including pulse stuff.

I never felt the urge to own a 5-10 GSPS super-expensive scope. Sure, at
times it would have been nice but I was always able to make a signal
reptitive enough that the HP displayed it.

One does not need a Lamborghini to haul some stuff from town

 

[[email protected]]

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

You can't lay off a scope. ;-)

 

[Joerg]

[...]

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

You can't lay off a scope. ;-)

Sure you can. On Ebay. And the upside is the scope, once sold, won't
turn around and serve you with a lawsuit about half a gazillion hours of
overtime that the scope feels it should have been paid for.

 

[[email protected]]

[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.

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

But IIRC there was that Dave Jones tuning

For SPI and particularly I2C, I'd really like to see both the analog and data
domains, particularly for triggering.

 

[Clifford Heath]

Unfortunately, my 600 ps mystery driver is only good for 6.5 volts
maybe

I don't know why you reckon your use of TinyLogic is secret, given
you've talked about them here more than once before? Do you use the
Schmidt trigger versions, or normal inverters? 6.5V is a little more
than Vmax, but that's never been known to stop you before .

Clifford Heath.

 

[Clifford Heath]

Looking at the 2N7002 data sheets, one would never expect the sorts of
speeds I'm seeing. All you can do is get some parts and try them.

The ones that switch fast seem to have low Cg, modest Rds-on, and peak
drain current ratings under an amp (which doesn't stop me from going
above an amp.)

I recall Win Hill getting kilovolt edges in a couple of ns from fets
that, from the data sheets, shouldn't do that.

I recall that was in response to a big discussion I triggered here when
I mentioned Tom McEwan's patents. He used various tricks, including
inductive peaking to drive the gate to what should have been twice
Vgs(max), saved by the source lead inductance.

Clifford Heath.

 

[Clifford Heath]

I won't judge anyone who does that, that's not up to me. Personally I
would not do it because it is squarely against biblical teaching, and I
try to live by that.

Would that be the biblical teaching in favor of genocide, or witch-burning?

What you think is Christian is predominantly the interpretation and ideology
of your chosen cultural group, with some ideas drawn from another stone-age
group; neither of which is informed by rational inquiry or material realities.

No, I'm not just bashing on religion from the outside. I've been there too,
got the t-shirt. I have no problem with people trusting G*d... but to do that
they must first trust themselves and other humans, and that's where the whole
edifice fails.

 

[Clifford Heath]

Far from true.

Whhooooosh. So far over your head, you've got no idea there's even a place where such ideas could exist. BTDT.

BTW, I have nothing against any individual, and respect you and Joerg more highly than almost anyone else here. Just don't get the impression that means I think you're right . I merely believe Jeremiah, that "The human heart is more deceitful than all else". It's incredibly difficult to clearly see and understand the things we can see or interact with physically, and impossible for things we can't - about those we can only have opinions. And luckily, that doesn't even matter much, and certainly doesn't impede our ability to lead an ethical and productive life.

 

[Joerg]

[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.

For SPI and particularly I2C, I'd really like to see both the analog and data
domains, particularly for triggering.

Well yeah, but sometimes if you want more and more features it gets more
expensive and then da boss says no. I'd rather have a simpler scope than
no scope at all. Some of the newer baseline models have a feature or an
option for purchase that adds 4-16 digital inputs for logic analysis. I
never felt the urge since I have a logic analyzer. That has a trigger
output for the scope but I haven't needed that in years.

 

[Joerg]

Well there are the socialist kind of trade unionized scopes that don't
work; so they won't sell from Ebay. However, they ask for expensive
genuine parts and an authorized shop for repair

And the li'l green line on the screen only shows up if a PLA is in
place. Oh, and you can't sell the old scope if cash-strapped. No, you
must sell the newest one first because of the seniority rule,
performance or usefulness if no interest

 

[Joerg]

Far from true. There's a continuous interpretive and theological
tradition that goes back to the apostolic period. The Church is the
mother of science and the inventor of the university.

I couldn't have said it any better than Phil. Just want to add that we
Christians try to follow Jesus' teachings, not witch burning or Old
Testament eye-for-eye type punishment. Unfortunately even the Christian
(Catholic) church did not follow Jesus in medieval times which is why
Mrtin Luther had to start reforming the church.

Far from it. Properly, the Church is organized so that no one is
without supervision, precisely because all of us, ministers and laity
and religious and all, are fallen human beings who sin every day despite
our best efforts.

It sounds like you had some bad experience, either through someone
else's sin, or through yours (or maybe both), and I'm sorry about that.
But unforgiveness like that will eat you alive, whether you return to
the church or not.

Goodness and faithfulness are difficult, and are made even more
difficult if one doesn't have the help of the Holy Spirit.

Amen.

 

[Nico Coesel]

Far from it. Properly, the Church is organized so that no one is
without supervision, precisely because all of us, ministers and laity

Keep on dreaming. Over here in NL and in Belgium there is a big
scandal going on concerning pedophiles in the church. There are dozens
of victims!

And its not limited to NL and Belgium:

http://www.thefreelibrary.com/HOUSE...r+abuse+at+Goldenbridge+orphanage.-a060662525
http://www.scribd.com/doc/53545205/...rafficking-Conducted-By-Nuns-Around-The-World

Right now its dinner time over here but I suddenly lost my appetite!

 

[Nico Coesel]

I didn't say that. I said I am personally against it. So, naturally, I
wish my tax Dollars not be used for that either. If someone commits a
sin it is not up to me to judge them but it is up to me not to support
that. Just like I do not support free drug use.

I wish the neighbours would think the same They are on holiday and
from the smell it seems their kids smoke a kilo of pot each day.

Of course there will always be triage type situations where there are
only two choices, between the yet unborn's survival and the mother's
survival. That's very different. What I meant was "doing it" and then,
whoops, "got to get rid of it". That is a grave sin.

I believe that labeling things as a sin usually ends up making the
wrong choices by not considering the circumstances. One of my former
teachers (a former priest) had an interesting example. One of his
parishioners had been living with his sister all his life. He was
afraid that he would not go to heaven because of that. My former
teacher told him that this sin would be forgiven because its not THAT
serious. His motivation was simple: true love between two adults can
never be wrong.

The real problem is ofcourse that the ofspring from a brother and
sister is prone to genetic defects. Much practical knowledge from
ancient times has been embedded as rules in religion. Like the Moslims
not eating pork and demand animals to be killed without being sedated.
Very few seem to wonder whether these rules still have value in a
modern society where food hygiene is way better.

I won't judge anyone who does that, that's not up to me. Personally I
would not do it because it is squarely against biblical teaching, and I
try to live by that.

The problem is that the bible never got updated. Remember that in the
old days most people didn't get much older than 35. Most died quickly
of diseases, wars or hard work. At old age your body slowly shuts down
organ by organ. Some organ failures like the kidneys cause a very slow
death (I'm talking months here!).

You mean abortion with that? Ever looked at an ultrasound before "legal"
abortion deadline? I have, I design part of those machines.

I'm sure the people who set the legal limit looked at all the facts
(and images) and made a well informed decision.

 

[Joerg]

Keep on dreaming. Over here in NL and in Belgium there is a big
scandal going on concerning pedophiles in the church. There are dozens
of victims!

Yeah, so now the arguments run out and you try to find a hair in the
soup. Sure there are sinful people in a church. If anyone in a church
claims to be without sin, run, because he or she is lying.

 

[Nico Coesel]

I'd certainly have had to be asleep to miss it, especially since it came
out in 2002 in the US. Nor is it limited to the Church--schoolteachers,
for instance, have a far worse record, at least over here.

As a Dutchman, if you really want something to turn your stomach, try
investigating the origins of all those trafficked slave women in the red
light district of Amsterdam. IIRC about 4 out of 5 were trafficked from
Russia and eastern Europe, and they suffer rape and worse, continually,
until they're too sick or too worn out to be worth anything any more.

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.

 

[Nico Coesel]

Yeah, so now the arguments run out and you try to find a hair in the
soup. Sure there are sinful people in a church. If anyone in a church
claims to be without sin, run, because he or she is lying.

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.