Single-cell fuel gauge with Impedance Track™
The BQ27421YZFR-G1A is a battery monitor from the Impedance Track™ series, designed for single-cell Lithium Ion packs. Its I²C interface reports state-of-charge without the learning cycle typical of voltage-based gauges — the algorithm compensates for discharge rate, temperature, and cell aging from the first full charge.
Package and footprint constraints
Housed in a 9-bump DSBGA — a wafer-level chip-scale package that requires a clean PCB land pattern and a solder-mask-defined pad for reliable assembly. Surface-mount only; no through-hole variant.
ROHS3 compliant.