It really is LM108 and LM112 (internally compensated) and there is admittedly no trick there. It has 1nA enter bias which happens to be quite secure with temperature as in most bipolar opamps simply because β truly enhances with temperature. Afterwards iterations like LT1008/LT1012 or OP97 pushed it down to https://jacquesc344cxq7.newbigblog.com/profile