ZHCSO20 may 2021 BQ25723
PRODUCTION DATA
The charger supports 10 mΩ and 5 mΩ for both input current sensing and charge current sensing. By default, 10 mΩ is enabled by POR setting RSNS_RAC=0b and RSNS_RSR=0b, if 5 mΩ sensing is used please configure RSNS_RAC=1b and RSNS_RSR=1b. 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 9-6:
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.
| INDUCTANCE (IADPT Pin Resistance) | EN_FAST_5MOHM | RSR_RAC BIT | MAXIMUM INPUT CURRENT LIMIT (IINDPM) |
|---|---|---|---|
|
1.0 uH(90.9 kΩ) 1.5 uH(121 kΩ) 2.2 uH(137 kΩ) |
Xb | RSNS_RAC=0b | 6.35 A |
| 1b | RSNS_RAC=1b | 6.35 A | |
| 0b | RSNS_RAC=1b | 10 A | |
| 3.3 uH(169 kΩ) | Xb | RSNS_RAC=0b | 6.35 A |
| Xb | RSNS_RAC=1b | 10 A |