This is regarding the selection of voltage reference IC for TI DSP TMS320F2808. TI recommends using high precision external reference TI part REF3020/3120 or equivalent. REF3020/3120 has temperature drift of 50ppm/=B0C (max) from 0=B0C to +70=B0= C and initial accuracy of 0.2%.
Would you please tell me how the temperature drift and initial accuracy are selected here?