SLUSEG4B December 2022 – February 2024 BQ25628 , BQ25629
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The BQ25628 and BQ25629 terminate a charge cycle when the battery voltage is above recharge threshold, the converter is in constant-voltage regulation and the current is below ITERM. Because constant-voltage regulation is required for termination, the BQ25628 and BQ25629 do not terminate while IINDPM, VINDPM or thermal regulation loops are active. After the charging cycle is completed, the BATFET turns off. The converter keeps running to power the system, and the BATFET can turn on again to engage supplement mode. Termination can be permanently disabled by writing 0 to EN_TERM bit prior to charge termination.
At low termination currents, due to the comparator offset, the actual termination current may be 10 mA to 20 mA higher than the termination target. In order to compensate for comparator offset, a programmable top-off timer can be applied after termination is detected. The top-off timer follows safety timer constraints, such that if the safety timers suspend, so does the top-off timer. Similarly, if the safety timers count at half-clock rate, so does the top-off timer. Refer to Section 8.3.5.5 for the list of conditions. The host can read CHG_STAT to find out the termination status.
Top-off timer gets reset by any of the following conditions:
The top-off timer settings are read in after is detected by the charger. Programming a top-off timer value after termination has no effect unless a recharge cycle is initiated. CHG_FLAG is set to 1 when entering top-off timer segment and again when the top-off timer expires.