Hi,
We found the abnormal spike seems related to PU resistance.
When pull up resistance 1K, the threshold is about 1.4V which causes data to stop pulling low.
We found an abnormal signal which will lead to PSU non-ACK.
The MCU on PSU seems to abort the I2C package once the symptom occurred.
Could you please let us know if there is any design limitation for the TI PCA9515A?
Below is schematic and block diagram for reference.
MB
PDB
C1= PMBUS_CLOCK(before TI I2C buffer)
C2= PMBUS_CLOCK(after TI I2C buffer)
C3= PMBUS_DATA(after TI I2C buffer)
When pull up 2K, the threshold is about 1.2V which is close to the boundary condition.
