New Analysis Posting

Very nice. Was there ever a 2nd source for the LM195 / LM395?

Thanks, - Win

whill_at_picovolt-dot-com

Not that I know of.

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

There are a number of interesting things in the die photo, figure 4.

For example, the 45V zener is made from seven Veb transistor zeners in series. Q9 is larger, befitting its higher mirror current. And the Q17 Q18 transistor island is smaller, despite its PNP carrying higher currents. (Q18 enhances the output base-current drive when Q19 sees high currents. Widlar described this in his LM12 design article, AN-446B. Hans Camenzind wrote about the scheme's stability issues when describing his enhanced low-voltage zsct1555 design for Zetex.)

One of the Q20 power collector connections is right in the middle of the die, is that very common? C1 is a giant 30pF part, is it really necessary?

Thanks, - Win

whill_at_picovolt-dot-com

...Jim Thompson

Is ICE still around? They used to do cool "teardown" analysis of ICs, which they published in multi-kilobuck, very slick booklets with neat color chip photos and discussions. Somebody, a rep I think, snuck me a few once.

John

They're pretty much out of the technical consulting business, opting instead to do "business" consulting... how to fund your own foundry and other such useless drivel ;-) I think they were acquired by Chipworks.

I wrote and presented a bunch of their analog seminars from about

Glen Madland and Howard Dicken haven't been active in the company in quite a while. They left Motorola in 1965 and hired me on-the-side.

...Jim Thompson

I attended one of their seminars in NYC either in the late '70s or early '80s. Good stuff, when it was possible for a reasonably sized company to have their own failure analysis lab. and be able to perform many of the procedures by hand with simple fixtures and tools. When I started asking for ion beam etchers, my company said, "Forget about it!" My most modern tools were a SEM, computer controlled die probe and a Jupiter Plasma etcher.

Al