ZHCSIJ0B July 2018 – February 2022 BQ25601D
PRODUCTION DATA
The device has built-in safety timer to prevent extended charging cycle due to abnormal battery conditions. The safety timer is 2 hours when the battery is below VBATLOWV threshold and 10 hours when the battery is higher than VBATLOWV threshold.
The user can program fast charge safety timer through I2C (CHG_TIMER bits). When safety timer expires, the fault register CHRG_FAULT bits are set to 11 and an INT is asserted to the host. The safety timer feature can be disabled through I2C by setting EN_TIMER bit
During input voltage, current, JEITA cool or thermal regulation, the safety timer counts at half clock rate as the actual charge current is likely to be below the register setting. For example, if the charger is in input current regulation (IDPM_STAT = 1) throughout the whole charging cycle, and the safety time is set to 5 hours, the safety timer will expire in 10 hours. This half clock rate feature can be disabled by writing 0 to TMR2X_EN bit.
During the fault, timer is suspended. Once the fault goes away, timer resumes. If user stops the current charging cycle, and start again, timer gets reset (toggle CE pin or CHRG_CONFIG bit).