ZHCSHR0B September 2017 – September 2019 BQ25910
PRODUCTION DATA.
The device charges the battery in two phases: constant current, and constant voltage. At the beginning of a charging cycle, the device checks the battery voltage and regulates current / voltage as needed. If the battery voltage is below VBAT_LOWV, it is the master charger responsibility to increase VBAT up to VBAT_LOWV so the parallel charger can initiate fast charging. As BAT increases to VBAT_LOWV, the master charger can stay in HIZ and the BQ25910 can start fast-charging the battery with up-to 6-A ICHG. Alternatively, the master charger can remain on to maintain the system load from adapter, while the BQ25910 charges the battery. The default charging settings can be found in Table 2.
VBAT | CHARGING CURRENT | REG DEFAULT SETTING | CHRG_STAT |
---|---|---|---|
< 2 V | Master controlled (IBATSHORT ) | BQ25910 off | 000 |
2 V – VBAT_LOWV | Master controlled (IPRECHG ) | BQ25910 off | 000 |
> VBAT_LOWV | ICHG | 3.500 A | 011 |
VREG | TAPER down to ITERM | 4.350 V | 100 |
If the charger device is in DPM regulation or thermal regulation during charging, the charging current can be less than the programmed value. In this case, termination is temporarily disabled and the charging safety timer is counted at half the clock rate.
After the device signals charge termination done (CHRG_TERM_FLAG = 1), the master charger may choose to continue charging in CV mode or finish the charging cycle completely. The BQ25910 will not start a re-charge cycle automatically, and a toggle on EN_CHG bit is required to restart a charge cycle.