We are in the process of bringing up a power board using the TPS65185 PMIC and are seeing an issue which we could use some help with. Specifically we are seeing that i2c communication with the device becomes unreliable when the PMIC is powered up and generating high voltage. We find that polling registers within the device can result in random interrupt status bits being reported or occasional NACK’s being returned when writing the subaddress byte to select a, valid, register to read.
If we poll the same registers when the PMIC is not generating high voltage there are no observable issues after 90 minutes of continuous running. When HV is being generated we see issues within 90 seconds.
The data sheet lists no restrictions on polling registers over i2c and lists no circumstances under which the device would return NACK on bytes written to it.
We have checked the PMIC power supplies and it they are clean during the period in question.
Has anyone had any similar issues with this device?