SLUUDA0 April 2026 BQ27Z855
The integrating delta-sigma ADC in the gauge measures the charge/discharge flow of the battery by measuring the voltage drop across a small-value sense resistor between the SRP and SRN pins. The 18-bit integrating ADC measures bipolar signals from –0.10 V to 0.10 V with 923nV resolution. The gauge reports charge activity when VSR= V(SRP) – V(SRN) is positive, and discharge activity when VSR = V(SRP) – V(SRN) is negative. This data is scaled and translated into mA using CC Gain and reported through Current(). The gauge uses this information for gauging and lifetime data logging functions. In NORMAL and SLEEP modes, the gauge continuously monitors the measured current and integrates the digital signal over time using an internal coulomb counter (also known as the integrated ADC), which handles the gauging.
In addition, the integrating ADC (CC2 filter of CCADC) is sampled during voltage measurements and converted to mA in the same manner. This data is used for gauging (but not coulomb counting) and reported through Cell 1 Current in DAStatus1().