Single-cell Li-Ion gas gauge with Impedance Track
The BQ27500DRZR-V120 is a single-cell (1S) Li-Ion battery monitor from Texas Instruments' Impedance Track™ series, communicating over an I²C bus. It reports state-of-charge, voltage, current, and temperature to the host controller without requiring a separate coulomb-counter IC.
Housed in a 12-VFDFN exposed-pad package (supplier device package 12-SON, 2.5x4 mm), the BQ27500DRZR-V120 is surface-mount only. The exposed paddle must be soldered to a PCB copper land for both thermal dissipation and the ground return — a cold joint here lifts the gauge accuracy. Cut Tape works for prototype or repair-bench runs where you only need a handful.
No pin-compatible second source or official successor is recorded — the BQ27500 family uses TI's proprietary Impedance Track algorithm, so a swap to a different gauge IC requires firmware changes.