Why no depletion mode LDOs?

May 06, 2012 102 Replies

Yep. I just posted a model (that you might be able to scale) under your other thread. ...Jim Thompson

| James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.

I had a case where any probe would make it work. The equivalent capacitor wouldn't. Turns out it was a broken wire. The probe flexed the board just enough to make it work.

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They are also big bureaucracies, think it through.

?-)

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So you frequently create designs where common LDOs do not work properly. Is that what you are saying?

?-)

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Dropbox is getting screwed up. It might be requiring cookies or scripts with no failure protection to alert the user/querant/person that such is required. this seems to be fairly common recently. =20

?-)

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This is Usenet, complaining about its nature is soooo weenie. =20

?-)

I'm complaining about a slimy old fool who keeps saying he's killfiled me and keeps lurking and cheating. Mostly I'm miffed about the waste of a perfectly good six-pack of Widmer wheat beer I sent him. If I'd known what a coarse redneck asshole he'd turn out to be, I'd have let him die of thirst in that hideous house in that Godforsaken bleak desert he lives in.

How's that for a Usenet rant?

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

I love Dropbox. I have a 100G folder on all of my computers, and anything I drop there appears on all of them. No more memory sticks to worry about! I can synchronize all my projects and datasheets and mail folders. It's just not very good for posting public files.

I also use it to swap files with other people, things like FPGA builds that are too big for email.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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Most pnp/pmos LDOs are pickey about the ESR of the load caps. They really don't need to be.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

Yeah, bureaucracy usually stifles everything in its path.

But, what can I say, one of them did come through: Infineon. In Germany there is one of those eternal jokes going around, that Siemens (from which they were spun off) is in reality a huge bank with an attached electric division. Long story short, their customer service used to be the pits and now their web site is thoroughly screwed up. Even the support form does not work. Then I usually write to their investor relations folks or whatever, because their clientele won't put up with captchas annd such nonsense. Got an answer and ... SPICE models! They have a whole line of depletion mode FETs, the BSP1xx series. It's like going to a Levy's jeans rack, you just pick you size. In this case Rdson and channel saturation current.

Regards, Joerg http://www.analogconsultants.com/

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No, I sometimes encounter designs where the complaint is that it occasionally does a tarantella dance and sometimes a pop is heard and a puff of smoke comes out. Part of a consultant's life is (usually) being the emergency room for such things. Several times I found an LDO to be the culprit. Things like this: "It used to work for all those years and now all of a sudden, poof" ... "Did you release a new capacitor for this board?" ... "Umm, why, yes because the old one was discontinued".

As John said, LDO chips can be designed properly but they typically aren't.

Regards, Joerg http://www.analogconsultants.com/

Is that safe in terms of data security and confidentiality? What's the catch? There must be a catch, there is no free lunch with web services.

For huge files I use FTP, and clients that are not used to that can download a little Mozilla thingamagic that allows them easy access. But I was amazed what email can do. The biggest one was when a client overseas sent me the whole chebang in one fell swoop instead of in chunks. 65MB, and it all arrived ok.

Regards, Joerg http://www.analogconsultants.com/

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Nothing is absolutely safe. I could lose a memory stick, too.

It's free for the first couple of GB of storage. I signed up for 100G for some modest annual fee. It really works well. It uses some very smart change detection algorithm, so I can copy a huge file or folder into my D:\Dropbox folder, and it only uploads the bits that changed.

I used to be limited to 10M in emails, but I don't know if they have changed that.

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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True. But in my case that's not the only backup and if someone beats me over the head and steals the stick he can only sell it as ... a stick. Because the data won't come off, the only thing a thief can do is re-format.

I think in this earthly life I won't entrust my data to some cloud. But I know companies who do.

That is very nifty. I wish that existed for sticks and stuff so it wouldn't take so long. It can run in the background but I had cases where I had a file open and the backup stalled at that location, had to be closed and repeated (all of it). IOW it only really works at night.

Best method is to try it out. Maybe have Rob send you an email with a really big attachment as a test.

Regards, Joerg http://www.analogconsultants.com/

I've sent myself 200+ MB e-mails through GMail (I haven't sent someone else a file that big, but I have no reason to doubt the same is available between GMail accounts). Not exactly secure, but you could encrypt a ZIP, then their ads wouldn't know what to make of it.

Tim

Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms

Google snoops the contents of email, don't they? I don't like that idea.

What happened to "do no evil" ?

John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

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and everything in cloud could be gone in an instant, the service could go broke or as with megaupload FBI gets a call from riaa/mpaa and they just shut it down with no way for people to get their data

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The funny thing is, for all the sheer privacy invasion capacity they have, they haven't abused it... much... ...yet.

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In the last five years or so, it seems TLAs are only beginning to appreciate how useful a resource they can be. Note that Google updated their privacy policy recently (last 6 mo.'s I think) which basically says "we look at everything", to whatever degree of "look" is met (most likely just algorithms primarily for advertising, but I'm sure an increasing number of more nefarious keywords are being tagged). This uniformly spans all services, from GMail to their cloud thing.

Tim

Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms

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If Dropbox vanished, everything I keep there is still present in files on at least three physically separated computers. When I put a file into any Dropbox folder on any drive, the others are immediately updated.

John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation

No

=46reaky.

?-)

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