The charger supports 10 mΩ and 5 mΩ for both input current sensing and charge current sensing. By default, 5 mΩ is enabled by POR setting RSNS_RAC=1b and RSNS_RSR=1b, if 10-mΩ sensing is used please configure RSNS_RAC=0b and RSNS_RSR=0b. Lower current sensing resistor can help improve overall charge efficiency especially under heavy load. At same time PSYS,IADPT,IBAT pin accuracy and IINDPM/ICHG/IOTG regulation accuracy get worse due to effective signal reduction in comparison to error signal components.

When RSNS_RAC=RSNS_RSR=0b and 10 mΩ is used for both input and charge current sensing, the pre-charge current clamp is 384 mA (2 A for 1S if VSYS_MIN>VBAT>3 V ), the maximum IIN_HOST setting is clamped at 6.35 A, and the maximum charge current is clamped at 8.128 A.

When RSNS_RAC=RSNS_RSR=1b and 5 mΩ is used for both input and charge current sensing, the charger will internally compensate pre-charge current clamp to be 384 mA (2 A for 1S if VSYS_MIN>VBAT>3 V ) under 5-mΩ current sensing which keeps consistent between 10 mΩ and 5 mΩ. Under 5-mΩ current sensing application charge current range is doubled to 16.256 A. Based on EN_FAST_5MOHM register bit status and IADPT pin resistor the maximum input current can be configured referring to Table 8-6:

For defined current sense resistors (10 mΩ/5 mΩ), PSYS function is still valid when unsymmetrical input current sense and charge current sense resistors are used. But RSNS_RAC and RSNS_RSR bit status have to be consistent with practical resistors used in the system.