Never Buy Maxim (again)

Or just scrunch your eyes closed really, really hard, to minimize what you learn.

The Boonton is plenty sensitive to measure 0.4 pF, or whatever the Maxim amp actually is.

But I was going to do it some other ways too:

Make a non-inverting amp, G=5, and drive its + input with a fast step through a big resistor, and see what the output looks like.

Build an inverting amp with big feedback resistors and look at gain/freq and noise peaking.

I especially enjoyed the Maxim engineer's "not characterized for dual supply operation" comment. I now know who *I* am dealing with.

Last time I used Maxim parts, we had to recall hundreds of timing modules and replace about 3000 pieces of MAX9690 comparators. They started failing after roughly a year of use, and eventually every one would have failed. The parts were actually fabbed (and maybe designed?) by a subcontractor, in Minnesota I heard.

We had to make 3000 of these to replace them:

It was rather an expensive nuisance.

Which is to say more of Greegor's contentless drivel.

It's strictly for your own good. The shameless information manipulation that lead you to believe that socialism and communism are the same thing needs to be shown up.

This thread started off on the defects of Maxim. A little bit of off-topic deviation is tolerable, but you are away with the fairies - of the old-fashioned asexual kind.

It's the quality of his content which is despicable, and earns him shame of place.

And what did FA say? Well assuming you contacted them. It is quite easy to find damage to chips given tools like emission microscopes. Generally failed parts are due to the customer, and you can get some good diagnostics by asking the factory how the part failed.

I had Moto bitching about one of my parts. They used 4 per board. Only one position on the board would have a failed part. Moto felt a bit stupid not noticing that and simply went away, presumably finding the problem since they kept buying the parts long after the incident. Pilot error. It is nearly always pilot error.

Designing ESD devices for interface chips, I spent some time in the FA lab destroying parts to understand what exactly fails. Emission microscopy detects stressed junctions, but some failures cause the juction to do ohmic. You can find those with a simple CCD, but liquid crystals is a better technique. The crystals will "boil" over the hot spot. You can pulse the chip to make the hot spot toggle, or my technique was to just leave it powered and bring a soldering iron close to the chip. The iron would get the crystals just ready to change state, making it a very sensitive technique.

Minnesota parts were from VTC. To my knowledge, they didn't have any designers, just a fab.

The outputs got erratic at high temperature, looked like a problem in the latch circuit. As the parts aged, the fail temperature descended, ultimately reaching room temp after about a year. All the parts did this. A good hi-temp bake would push the fail temperature up, and it would begin slowly descending again from there. What would cause that?

Our first indication that something was wrong was when parts wouldn't ship, with no explanation. Then the part was discontinued, delivery infinite days ARO, again without explanation. That was about the time they started failing.

I eventually found a guy at Maxim who explained the Minnesota problem. He sent me 3000 samples of the MAX9691. The 9691 is a *comparator* with back-to-back diodes across the inputs (!!!!???) which is why we had to make the adapter boards.

That would be correct. Quite a nice fab. Excellent BiCMOS processes. ...Jim Thompson

BS > Jim-out-of-touch-with-reality-Thompson strikes again. BS > John Larkin exhibits a much broader spectrum of BS > ignorance than krw, and has been known to post BS > circuit diagrams and LTSpice net-lists. BS > BS > We may be arguing precedence between a flea BS > and a louse, but Larkin is definitely the BS > performing flea and krw the crawling louse. G > Has your wife been catching on to you, slow man? BS > I wonder what that was intended to mean? G > It was open ended. BS > Which is to say more of Greegor's contentless drivel. Flatterer. G > Your rundown seems like a catharsis for you. BS > My mother just died, and my kidney stone BS > has been lithotripted into a very small BS > pieces, which also seemed to turn off BS > my right kidney for three days. BS > BS > Losing a parent - or what was left BS > of her at 95 - probably qualifies BS > as catharsis, but I don't need BS > purification or cleansing to find BS > an excuse to be rude about krw who BS > must rate as the most despicable BS > non-contributor to this usegroup. BS > BS > He doesn't like me much either. G > Slow Man: When avowed socialists from G > other countries start manipulating G > information to try to sell Socialism G > to people in the USA, we don't like it. BS > It's strictly for your own good. Socialists and Stateists say that a lot! BS > The shameless information manipulation BS > that lead you to believe that socialism BS > and communism are the same thing needs BS > to be shown up. I compared you to another avowed SOCIALIST, not a communist and what was your reaction? BS > I'm starting to think you are more dishonest than I thought. G > I know that Jim Thompson thinks that G > this usenet group is dominated by G > left wing posters, but it's not as G > left wing dominated as the rest of G > usenet is. G > G > My personal belief BS > Just put your fingers in your ears and make childish noises, Slow man. BS > This thread started off on the defects of BS > Maxim. A little bit of off-topic deviation BS > is tolerable, but you are away with the BS > fairies - of the old-fashioned asexual kind. You ad-hommed 3 regular posters all at once. Typical of Socialists and Aspies you frequently put on aires of superiority, disrespect others and present YOUR prejudices as enlightenment. When I pointed out that you are an avowed Socialist, you tried danced around that fact, comparing different political parties in Australia, none of which had any bearing on the simple fact that you are an outright Socialist. Why do you try so hard to weasel out of that?

I make all sorts of "useless" measurements. Some of them turn out to be very useful.

You define yourself by the things that you are not interested in.

Slow man: In 5,000 words or less could you please explain why you think your fecal matter doesn't smell bad? No dissertation on your diet or semantic arguments about the relative meaning of the word "bad", please.

JL > The outputs got erratic at high temperature, JL > looked like a problem in the latch circuit. JL > As the parts aged, the fail temperature JL > descended, ultimately reaching room temp JL > after about a year. All the parts did this. JL > A good hi-temp bake would push the fail JL > temperature up, and it would begin slowly JL > descending again from there. What would cause that? Hygroscopy - tending to absorb moisture from the air Did somebody get the wrong polymer for the chip packages? The porosity or permeability of plastics are counter intuitive. Jim Thompson: Please tell us what you would suggest could cause such odd symptoms. In the middle 80's there were reports of water droplets inside of DRAM chips causing intermittent failures. Was that likely the real issue?

Ahhh, this subject remind me one of the funny Max device... let say deviceX

The spec saying that device X has an output pin to indicate its input signal presents or not (kind of LOST signal)... and somewhere the spec say it's an open collector

We didn't care it's open drain or not, since we do not use that damn pin for any purpose.. just simple as we don't care like an X in logic, no micro controller on board, or anyone who cares about that LOST... So we let it float

Guess what? we get the board built - and power it up, device X kept sleeping as it has been slept for age since its birth

Anyone knows why it didn't wake up?

AFAIUI, MOSFETs slowly shift threshold a bit when you apply continous DC voltage to the gate. Something to do with trapped charges. Annealing at high temperature can reverse some of that.

It was a big problem with CMOS-input op-amps used as precision comparators, but less of a problem with ideal op-amp circuits because the inputs would usually be balanced, so the shifts would cancel out.

AFAIUI chips are normally passivated (there's effectively a layer of glass- actually SiOx/SiNx- on top of the chip with "holes" for the bonding pads. Conformal coating at the chip level. So, moisture is unlikely to be an issue in a low impedance circuit.

Because you let that "output" float? What was the p/n?

I was sure he meant the new one, but the old one with George C. Scott is a pretty good ghost story, thanks mostly to him.

MOSFET threshold shift due to crappy or too-thin oxide, maybe. Or possibly die stress due to the package swelling from moisture. If it were a passivation problem, it would be unlikely to be (temporarily) fixed so easily, and anyway it isn't very difficult to fix a passivation step.

Sounds like somebody realized they had a threshold shift problem.

Cheers

Phil Hobbs

They used to have own-brand parts, including a really nice 70 MHz dual OTA.

Cheers

Phil Hobbs

that's right

Input has valid signal, power pins has good clean supply all are normal, but the chip refuse to work because the LOST pin doesn't have pull up

Their logic is this, if LOST signal is low, output must shutdown...

they don't care if the input present or not.. even they don't care to say something about the auto-shutdown at the outputs in their spec

:-)))

Anyway, we gave up our "don't care' and we must use their 'don't care'

after that I dont care anything from Max