Has anyone checked performance of the REF voltage of temperature stabilised buried zener inside the LM723?
Hmm,
I cannot find the term "buried zener" in the current data sheet.
I am reading only "temperature compensated zener".
So from where do you have the term "buried zener" for the LM723?
On the other side: the specified ageing of 0.05%/1000 hours (500 ppm or 3.5 mV per 1000 hours)
would correspond to the measured data with drift in the mV range.
Buried zener references are usually specced with 30 ppm/1000 hours or better.
with best regards
Andreas