Electronics > Projects, Designs, and Technical Stuff
LM399 - die analysis
Noopy:
Hi all,
I have took a closer look on a LM399 shunt reference.
Actually it´s a HP-part...
You can find the whole story here:
https://www.richis-lab.de/REF02.htm
(german)
A nice die with big structures! 8)
Reverse engineering is not a big deal:
And here is the buried zener:
I found a circuit that´s not in the datasheet:
It seems they had to do some fancy compensation. :-/O
And here the heater-circuit:
I wrote a lot about the circuit but it´s too late to translate all that words to english. Please use the google translator and ask me whatever you want. :popcorn:
BTW:
I also have a PMI REF01:
https://www.richis-lab.de/REF01.htm
Interesting point: The new ones are ADR01 named REF01.
Have fun! :popcorn:
…does anybody want to donate me a (dead) LTZ1000? ;D
Update: Hey, it seem´s that I´ll get one out of the german mikrocontroller.net-Forum! :clap: :clap: :clap:
iMo:
--- Quote ---Bei der Z-Diode D1 handelt es sich anscheinend um die gleiche Subsurface-Diode wie im Shuntregler.
--- End quote ---
Yes, the Dobkin's paper confirms that.
2 burried zeners there.
PS: I can send you a MAC199 (TESLA's highest grade LM399 clone) for de-capping if interested.
PPS: TESLA's schematics show the missing transistor and resistors, there is even one additional transistor more :)
rhb:
What is a 1991 die doing in a 1985 date code package? Where did the device come from?
Squiddaddy:
Looks like 199 I to me, not 1991.
chickenHeadKnob:
--- Quote from: rhb on January 18, 2020, 12:02:22 am ---What is a 1991 die doing in a 1985 date code package? Where did the device come from?
--- End quote ---
The original part was LM 199
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