The BQ25798 is a fully integrated switch-mode buck-boost charger for 1-4 cell Li-ion batteries and Li-polymer batteries. The integration includes 4 switching MOSFETs (Q1, Q2, Q3, Q4), input and charging current sensing circuits, the battery FET (QBAT) and all the loop compensation of the buck-boost converter. It uses NVDC power path management, regulating the system slightly above the battery voltage without dropping below a configurable minimum system voltage. When system power exceeds the input source rating, battery supplement mode supports the system without overloading the input source. BQ25798provides a simple interface to small photovoltaic panels using its built-in VOC scaling MPPT algorithm.