What this part does on the board
The Texas Instruments TPS65013RGZT is a multi-function controller designed to manage a single-cell Lithium Ion or Lithium Polymer battery in portable equipment. It communicates over I²C and USB, so the host microcontroller can read battery status and handle charging profiles through the same bus.
It is a current-production TI part, ROHS3 compliant, and available through independent distribution.
The 48-VFQFN exposed-pad package (supplier device package 48-VQFN, 7x7 mm) is a surface-mount part. Without those vias, the junction temperature climbs faster than expected when the charge controller is sourcing current.
Interface fit — I²C and USB on the same chip
Having both I²C and USB on the same multi-function controller simplifies the BOM for portable devices that charge over USB and communicate battery data over I²C. The host reads the battery fuel gauge and charge state through the I²C registers, while the USB interface handles the charging protocol negotiation. This consolidation saves a separate charge-controller IC and a fuel-gauge IC in many designs.