Voltage reference datasheets specify output voltage hysteresis by certain temperature cycle.
My questions are
1. What is the temperature curve used for testing Vref? - lets say 25°C to 125°C to 25°C (half cycle)
- What is the ramp rate from 25->125
- How log must stay at 125?
- what is the ramp-down rate 125-> 25
- how long must stay back at 25C before taking measurement.
2. Is there an industrial standard defining the test procedure for voltage hysteresis?
I did caracterization of few voltage references. Results shows that they srongly depend on temerature curve - e.g. - tests 25->70->25 - gives anything between 2...90 ppm. I wonder how AD tests it and is numbers cross comparable between deferent manufacurers.
Best Regards,
Mirtcho