Single-cell Li-Ion fuel gauge with Impedance Track™
The Texas Instruments BQ27545YZFR-G1 is a single-cell Lithium Ion battery monitor that uses the Impedance Track™ algorithm to report state-of-charge, state-of-health, and remaining capacity. It communicates over HDQ or I²C to a host controller, and the algorithm self-learns battery impedance over aging cycles — so the reported charge stays accurate without periodic full-discharge recalibrations.
Industrial temperature range — outdoor and portable gear
The DSBGA-15 package (15-UFBGA) keeps the footprint small — about 2.5 mm per side — which matters when the gauge sits directly on the battery cell tab in a tight assembly.
Active production — no LTB watch needed
That means standard lead times through the franchised channel, no premium for broker stock, and no pressure to last-time-buy. For a BOM line that runs for years in a field-replaceable battery pack, this is the right lifecycle posture.
Interface options and pack topology
The part supports both HDQ (single-wire) and I²C (two-wire) host interfaces — the firmware team picks the bus that matches the MCU peripheral map. It monitors exactly one series cell; a 2S pack requires a different gauge or a stacked configuration. The base product number BQ27545 covers the family; the -G1 suffix indicates the specific firmware variant and DSBGA-15 package.