Dear Experts:
My customer is asking us whether there is any power up sequency requirement of OPA2314. During the power up, both the input voltage and OPA 5V power supply ramp up. The input voltage at pin 3 (positive input) has chances to be higher than the power supply as below:
The input of OPA2314 is driven from on board voltage reference IC, and the output of OPA2314 will drive multiple DACs' reference input. Customer report that some devices(3 out of 200) can not buffer out the reference input voltage correctly. By repeating power up sequence, they found that sometimes the output of OPA2314 ramp up to 3V for 1 seccond, then fall back to and stay at 0.65V. At this stable state, pin3(posistive input pin of OPA) stays at 2.5V and negative pin stays at 0.54V. I am suspecting whether this board has soldering problem while customer denies it.
Could you please help to comments whether the device has special power up sequence? Thank you.
Yarn