Hello,
already did similar with a BCV62 (current mirror) with zener connected transistor and diode.
https://www.eevblog.com/forum/projects/low-cost-voltage-reference-experiment/msg633042/#msg633042
As they only guarantee the zener voltage is > 5V it will be usually not in a useful range for tempco compensation.
I got 8-9V on a simple test which is much too high against the ~6.25V needed.
So I think you will have to buy many MAT01 to find a pair with such low breakdown voltage.
You have many ideas.
Why not build your own low noise amplifier and report your measurement results?
with best regards
Andreas
thanks for the input. a couple of points though.
1. since I am located in Pakistan, it is generally difficult to get hold of quality parts, so my proposals may sound funny.
2. yes noise testing is the key, that is probably the first piece of equipment any serious volt-nutter should have or build.
(point me in the right direction here.)
3. MAT01AH is already guaranteed to breakdown at the usual five to six volt region (zener as opposed to avalance breakdown).
4. i tend to think that if you did your selection from low-noise transistors otherwise, you may get much better long term drift specs,
and MAT01AH is already pretty lownoise, along with guaranteed long term drift rates. (availability might be an issue).
so using the MAT01AH's transistors as zener + diode combination and doing a sweep on the operating current while monitoring
noise may be worthwhile.
regards, and thanks again for your input.