inverting dc-dc converter circuit

I have 60 or so oscillscopes, but no 2465s.

I rarely use an analog scope. The only one I occasionally use is a Tek

The old Tek storage CRTs don't hold up very well.

My favorite scope is probably my 11802, a 20 GHz sampler. It's digital, but actually uses a magnetic-deflection CRT for waveform display.

John

Have you contacted the apps engineer and complained about the lack of high voltage FET drive? Specs have to start someplace. Now generally the product definer does some tear downs and tries to find common ground between a few products on the market already.

Often the designer gets a project like do the blah blah blah chip, but make it do blah blah blah voltage, or some other spec. The task comes from a customer that liked a certain part, but needed a better spec.

Price is always negotiable, especially if you buy other parts from the same manufacturer. If you buy from disty, well, I guess that isn't an option. Is LTC so big you can't talk to someone?

Well yeah, but that's National. ;-) TI is a good jelly bean company.

You can whack a power supply once and most customers won't notice and probably no harm done, especially in your proprietary product. For a stand alone chip, somebody would spot the thunk and complain.

Back in '64, my best electronics technician student, Jim Foster, told of having aluminum poured _in_ his shoe when he worked in a foundry in Michigan. When he got out of hospital he came to Arizona, and my class. Naturally, when he graduated, I hired him. Except for some moving hiccups, where he worked for Widlar for almost a year, he worked for me from 1964-1989... he is the secretary of my extensive design notes over all those years :-) ...Jim Thompson

Spammers and trolls use that fake address, along with thieves as a reply too address when they are phishing and want you to visit a website to give them your personal information. A lot of people filter it out. I do, on some other newsgroups.

It's not in my filter file, but maybe Supernews rejects it.

John

Well, ok, then I have to revert to the old NOTTHIS and REMOVETHAT trick like you do. But that had caused complaints in foreign-language NGs. Maybe I should learn to ignore such complaints :-)

Yes.

IMHO that wrong VCC is a true blooper. If you market stuff in the HV world you've got to look at the available power devices. Simple.

Sometimes even customers are wrong. When they say "I want to drive this and that FET with it" you've got to look at the datasheets. And they will say 10V Vgs. As a consultant I do such diligence all day long, for the sake of my customer. I can't count anymore how many times I've heard "Oh dang! Thanks for pointing that out."

No, LTC is a fine company. One of my favorite suppliers. But you can't negotiate $3 down to 75c and that's where some of my designs have to be, and usually are ;-)

I stumbled on this while looking for something else and thought of this thread.

If you want a dedicated controller with integrated features look at the the UC3572. They dont say what the minumum frequency is; the max is 300kHz.

Larkin's circuit can be improved by making it PWM'd control. I've done that sort of thing with a pack of LM339's, plus a TL431 for accurate voltage. ...Jim Thompson