drift for periods longer than 1000 hours?
Here is the equation for an estimation of a reference’s output long-term drift
for periods longer than 1000 hours.
LTD= √drift period in hours * (drift @ 1k hours)/√1000
For ADR01/ADR01A: For a 1,000-hour LTD typical spec of 50 ppm and a term of
250800 hours, the estimated drift is:
LTD = √250800 * 50/√1000 = 791 ppm
You need to check the electrical tables for the listed parts. If they are 50ppm
for 1k hours, then the numbers are the same. If the 1k hour drift is different,
then you need to plug in that number.