Thank you, Andreas, however the ADR01 is a refined band-gap, pin compatible with the REF01.
I'm looking at that particular reference as it has a temperature monitor output and can be compensated to almost zero tempco in a narrow range, I think.
Hello,
sorry for mixing up. I only know ADR as XFET (ADR445, ADR435, ADR425, ADR4550 ...)
But Band-Gap references also suffer from larger ageing than buried zeners.
(at least for the reference element itself).
If you want to compensate the T.C. to get further improvement then 2 other effects will annoy you:
1. humidity: may be up to 0.5ppm/% relative humidity for plastic packages
(you can see this in the curve for the LT1027CCN8-5 of ADC4 + ADC8)
2. Thermal hysteresis. This depends on IC package but may be
in the 10-30ppm range especially for non stiff (small) packages
for a small temperature range (e.g. 10-40 deg C).
Thermal hysteresis is also dependent on temperature change speed (gradient).
I have already thought of using the trimming pin of a LT1236AILS8-5 as temperature output to compensate its T.C.
But this needs buffering and probably a 2nd high resolution ADC to get a temperature resolution high enough to
get good results without additional temperature steps in the output.
Another possibility for temperature compensation is described on the page of geller labs.
http://www.gellerlabs.com/Voltage_References/SVRTH/SVR%20THR%20Sch.jpgThis can be used with every reference with a trim pin for a small temperature range.
with best regards
Andreas