AD violates the Prime Directive: Never Buy Maxim

Stodgy New England tech company. I expect they will continue to be a stodgy New England tech company.

ADI makes a lot of great parts.

Comparators, chopamps, references, fast amps, adcs, dacs, isolators.

So does TI. It's good we have both.

I don't think they've mucked too much with LTSpice. yet.

I like AD's isolated gate drivers better than the equivalent parts from Silicon Labs, the AD devices are rugged, and don't have to bake them in an oven because you took them out of the bag for 5 seconds.

Interesting. Makes sense.

The demise of formerly second-sourced chips is a live issue, because as we all know, not every part with a similar name is actually similar.

The poster child is the On Semi version of the TLV431, which is unstable over a whole lot of the (I_anode, C_load) range you'd want to use, whereas the Diodes Inc version is much much better. TLV431 fans should hope that On Semi doesn't merge with Diodes. ;)

Must have been really really tight if that little bit of area was a deal breaker.

I've done one downhole design--it was an ultrastable cavity-locked diode laser for an interferometric gravity sensor intended for exploration and oil field management. A different operating regime than my usual, for sure.

I tried pretty hard to convince the customer's customer (Baker Hughes) to fund the development of a thermoacoustic fridge--no moving parts, all metal and ceramic--that would have gotten us a 25C cold plate in a 200C ambient.

TA friges are magic--you heat one end with e.g. a Chromalox element, the other end gets cold, and you take the heat out in the middle. Their construction would easily survive being pulled out of the ground, uncoupled, chucked into the back of a truck, and driven miles over washboard to the next hole.

However, BH wasn't having it--apparently there was some 'wisdom' in the field that fridges were junk. Of course, it was based on anecdotal experience with free-piston Stirling fridges, which are about the furthest thing from robust.

I'd very much like a chance for another crack at it--I still think it would make a big dent.

Cheers

Phil Hobbs

VTC. They were a spinoff of Control Data, I think. CD used to make high end disk drives IIRC, which needed really fast comparators. I remember having a VTC databook, but gifted it long ago, along with two copy-paper boxes of other old databooks. As I recall their offerings were rather limited. I don't remember who fabbed their parts, they might have done it themselves. I believe I know someone who used to work for them.

Did a little digging. VTC was originally the Control Data Microelectronics Division, with their own fab. It still exists, now known as Polar Semiconductor, and appears to be a wholly-owned subsidiary of and captive supplier to Sanken Electric.

Huh. Long time before my time this "Control Data" (I was born at the end of the 70s...), at one time everyone in my area of Massachusetts knew someone who worked for DEC. I learned about DEC in the early 90s just because maybe one of my buddy's fathers had worked for them, or knew someone etc. and he had got his hands on a big pile of DEC-branded three-ring binders from somewhere. They were free for the asking for us and we used them to store our Dungeons & Dragons character sheets.

I used to really like their fast OTAs--VT713 iirc. About 70 MHz bandwidth at maximum bias, in about 1990. That sort of performance didn't resurface till the LT1228 came out.

Cheers

Phil Hobbs

VA2713, it was. A true thing of beauty.

Cheers

Phil Hobbs

Polar is right next to the mall of america. I was real excited to see the outside of their plant. It's all analog stuff being made there, mostly for automotive as I understand.

Years ago I needed some high voltage Sanken rectifiers- it was surprisingly hard to find a distributor and then actually get the parts. I think Sanken also owns Allegro too.