I want to use bq24753A (https://www.ti.com/lit/ds/slus920/slus920.pdf) battery charger to charge 2 LiPo in series. But my input voltage can vary from 9V to 15V. Will it cause any problem because there are some pins whose voltage depend on input voltage. But the charger also has a buck converter. So, I am not sure if need a extra regulator for the input voltage or not. Could someone explain?