On page 7 of the (discontinued) LF351 datasheet, they have the
schematic:
http://cache.national.com/ds/LF/LF351.pdf#page=7
Overall, the architecture looks pretty similar to every other OA. It's
JFET input. There are current limiters at the output. etc. etc.
However, I don't understand the purpose of Q17. In fact, I can't
imagine a time when it would ever become active!
I have a feeling it's there to protect the JFETs somehow, but it's
unclear to me how it could.
Could someone help?
Thanks --
Ted
