THIS STILL NEEDS TO BE VERIFIED - STAY TUNED
The Vin pin and PVIN pin can be powered from different voltages based on the abs max rating information on the datasheet.
If there was a limitation on voltage applied that would be listed here (for example Vin to PVIN range would be limited by 0.3V because of ESD diode protection)
Also the EC table shows that both VIN and PVIN can be powered from 2.7V to 6.5V.
The main limitation is the fact that PVIN does not have an UVLO but VIN does have the UVLO at 2.6V.
So if you have power on PVIN (5V) and VIN rises to 2.6V then the regulator starts switching at Vin = 2.6V.
If you have power at VIN (5V) the converter will start switching even if PVIN is not powered and therefore as soon as power is applied to PVIN the regulator will most likely be running at 100% duty cycle and draw maximum current.
So ideally you apply PVIN before VIN or you can use a resistor divider on PVIN to EN to guarantee that you do not start switching until PVIN has sufficient voltage on it. A delay can be applied to the EN pin also with a cap)
Best Regards,
LucaV
Message was edited by: Luca Vassalli