SLUSEK7 September 2024 BQ25773
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The charger supports 10 mΩ and 5 mΩ for input current sensing . By default 10 mΩ is enabled by POR setting RSNS_RAC=0b. If 5-mΩ sensing is used, configure RSNS_RAC=1b. Lower current sensing resistor can help improve overall charge efficiency especially under heavy load. At same time, PSYS/IADPT pin accuracy and IINDPM/IOTG regulation accuracy get worse due to effective signal reduction in comparison to error signal components.
The charger supports 5 mΩ and 2 mΩ for charge current sensing . By default 5 mΩ is enabled by POR setting RSNS_RSR=0b. If 2-mΩ sensing is used, configure RSNS_RSR=1b. Lower current sensing resistor can help improve overall charge efficiency especially under heavy load. At same time, PSYS/IBAT pin accuracy and ICHG/IPRECHG regulation accuracy is reduced due to effective signal reduction in comparison to error signal components.
When RSNS_RAC=RSNS_RSR=0b, 10 mΩ is used for input current sensing and 5 mΩ is used for charge current sensing, the pre-charge current upper limit is clamped at 2016 mA through IPRECHG() register, the maximum IIN_HOST setting is clamped at 8.2 A, and the maximum charge current is clamped at 16.32 A.
When RSNS_RAC=RSNS_RSR=1b, 5 mΩ is used for input current sensing and 2 mΩ is used for charge current sensing, the maximum IIN_HOST setting is clamped at 16.4 A. The maximum charge current is clamped at 30 A (with 20 mA LSB , 5DCh for CHARGE_CURRENT[13:3]). System note: Under 2-mΩ charge resistor, the pre-charge current upper limit is compensated and still clamped at 2040 mA through IPRECHG() register (66H). However IBAT_SHORT does not need to be compensated should increase from 128 mA (RSR=5 mΩ) to 320 mA(RSR=2 mΩ).
If PSYS function is needed, practical input current sensing and charge current sensing should be consistent with RSNS_RSR and RSNS_RAC configuration. This is necessary because of the PSYS calculation method referring to Equation 2.