The BQ25185 integrates a linear charger that allows the battery to be charged with a resistor configurable charge current of up to 1 A. In addition to the charge current, other charging parameters can be programmed through external resistors such as battery regulation voltage and input current limit.

The power path allows the system to be powered from a regulated output, SYS, even when the battery is empty or charging, by drawing power from IN pin. It also prioritizes the system load in SYS, reducing the charging current, if necessary, in order support the load when input power is limited. If the input supply is removed and the battery voltage level is above V_BUVLO, SYS will automatically and seamlessly switch to battery power.

Charging is done through the internal battery MOSFET. There are several loops that influence the charge current: constant current loop (CC), constant voltage loop (CV), input current limit, thermal regulation, VDPPM, and VINDPM. During the charging process, all loops are enabled and the one that is dominant takes control.

The device supports multiple battery chemistries for single-cell applications, through adjustable battery regulation voltage regulation (V_BATREG) and charge current (I_CHG) options.