How to generate clean +/-12V for op-amps from +5/3.3V?

This part apparently has a compound cmos-bipolar output stage. Ron is high when measured at low current, near the rails, but it can still furnish 3/7 amps once a junction drop is exceeded, or something like that. It behaves similarly to a push-pull cmos driver followed by complementary emitter followers.

Can you get 3 amps in 12 ns from that?!

OK, but that takes more room, and then you have placement costs. It costs me about 25 cents to place a part, which changes my economics.

John

That would be ok. I got spooked by the RDSon versus supply voltage graph which doesn't look that encouraging.

No, but usually I don't have to.

Sounds like hand-placement pricing. Then it's a different game. I mostly calculate under 1/2c (China).

What I like about the LM5112 is the brown-out feature. Maybe I should use it some day.

We have two Essemtec semi-auto pnp machines, which move along pretty well, but we build in smallish batches, and pay people well, and have health insurance and 401Ks and running water and stuff. Not to mention the fleet of executive jets, and the yacht, and the limos.

So parts count is a major factor in design. We run, overall, roughly

It's a pretty spiffy part, especially for something so tiny. The schmitt input makes it a power oscillator, too.

John

Probably it's the amortization versus stand-still times that kills cost efficiency. Although if you have two machines they should be quite busy. Can't farm that out? Maybe get a quote from W.D.Burch or places like that, they did a really nice job on one of my larger board designs this year (the one with the short VME form factor). Seems like a good old American family business.

If that's placed, mounted, crated and OTD versus revenue that is very healthy indeed. That ought to leave some budget for that black stretch limo with the glistening lights.

It is spiffy. I wonder why many other parts don't have Schmitts, without that you can't easily use a part for any unorthodox stuff. Except truly analog like with a CD4049UBE.

Another inexperienced youngster ;-)

It's an SCR.

...Jim Thompson

Well, I know that it's an SCR. Thing is, SCRs aren't exactly rockets when it comes to switching times. More like a stage coach.

How was San Diego? I used to go to Rancho Bernardo a lot but then our company bought the one down there and eventually re-located it to up here.

Wouldn't matter if it accidentally fired. It's a flyback diode function. It'd only bypass the other diode that was supplying current to the negative load.

Cold ;-)

I used to go all the way out to Grass Valley/Nevada City when SSI/TI was still there.

...Jim Thompson

Hmm, looking at the schematic again, when M1 turns on while X1 hasn't cleared its throat yet ... +12V=GND ... phssst ... BOOM. But I don't know this particular SCR, probably ok if SWControl is slow and loads are defined.

Reminds me of a brief period where TV mfgs did the H-stages with SCRs. All peachy during normal operation until something innocent happened like a loose contact or solder joint at the CRT connections. Even tube TVs couldn't display such a pyrotechnic show, usually a total loss. That's how I got an almost new CRT for a set that I bought off a TV tech (his son had taken up an active role during Bonanza, with a huge sling shot, and got the bad guy).

When I went with folks to pick out a new set I asked "...'tis not an SCR-chassis, is it?" Sweat beads showing up on sales guy's forehead, owner joins in. "Ahm, let's look at the brochure one more time to make sure we find a perfect fit for you guys".

Much in this area is gone. Except for medical where there are still a few high-tech companies. For me this means more travel. It's weird, getting to a client in L.A. (500 miles) takes less time than driving to a client in the Bay Area (120 miles). I always look down before landing at LAX and then tell the cab driver which routes looked plugged up.