The BQ27500DRZT-V120 is a single-cell Li-Ion battery monitor from Texas Instruments' Impedance Track™ series, communicating over an I²C interface.
Package and mounting — the 12-SON footprint
Housed in a 12-VFDFN exposed pad package, the supplier device package is 12-SON measuring 2.5x4 mm. Surface-mount assembly with the exposed pad also serves as the primary heat path. The small footprint suits space-constrained designs, but the pad's copper area on the board determines the effective thermal resistance.
Fault protection and chemistry support
The device includes over-temperature fault protection and is designed specifically for Lithium Ion chemistry. It monitors a single cell, so a 2-cell pack requires a different gauge or an external balancer.