ZHCSDI4D March 2015 – October 2022 BQ25890 , BQ25892
PRODUCTION DATA
The device monitors the internal junction temperature TJ to avoid overheat the chip and limits the IC surface temperature in buck mode. When the internal junction temperature exceeds the preset thermal regulation limit (TREG bits), the device lowers down the charge current. The wide thermal regulation range from 60°C to 120°C allows the user to optimize the system thermal performance.
During thermal regulation, the actual charging current is usually below the programmed battery charging current. Therefore, termination is disabled, the safety timer runs at half the clock rate, and the status register THERM_STAT bit goes high.
Additionally, the device has thermal shutdown to turn off the converter and BATFET when IC surface temperature exceeds TSHUT. The fault register CHRG_FAULT is set to 10 and an INT is asserted to the host. The BATFET and converter is enabled to recover when IC temperature is below TSHUT_HYS.