Hi Experts,
Good day.
We have few questions about the ADC128S102QML-SP part.
If the analog inputs are active before the power up is complete are there any known issues?
I notice there is a power up sequence. Is a power down sequence required?
Thank you for your guidance.
Regards,
Archie A.
Hello Archie,
I must point out that driving the inputs of the ADC before VA is against the operating conditions.
In this scenario, the inputs have ESD diodes that turn on when Vin>VA, and redirect the input current to the power supply, VA. To protect the device, the input current needs to be limited, note the datasheet outlines an Abs Max of 10mA to any one pin, we suggest a more conservative limit of 2 mA. Also, this means that the source of VA will need to be able to sink the redirected input current.
As for a power down sequence, there is no defined sequence, simply maintain operating conditions. a suggested power down sequence would be to power down analog inputs, then VD, followed by VA, or all simultaneously would be acceptable as well.
Regards
Cynthia
