7.4.4.2 Thermal Regulation and Thermal Shutdown

The device monitors internal junction temperature T_J to avoid overheating the chip and limits the device surface temperature in buck mode. When the internal junction temperature exceeds the preset thermal regulation limit (TREG bits), the device reduces charge current. A 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 value in ICHG registers. Therefore, termination is disabled, the safety timer runs at half the clock rate, the status register TREG_STAT bit goes high, and an INT is asserted to the host.

Additionally, the device has thermal shutdown to turn off the converter when device surface temperature exceeds T_SHUT. The fault register TSHUT_STAT is set and an INT pulse is asserted to the host. The converter turns back on when device temperature is below T_{SHUT_HYS}.