SLVSB64I November 2011 – March 2018 TPS65217
Under some circumstances, the charger current is decreased to ensure support when changes in the system load or junction temperature occur. Two events can decrease the charging current. The first event is an increase in the system load current, which causes the DPPM loop to decrease the available charging current. The second event is when the junction temperature exceeds the temperature regulation limit (TJ(REG)), which causes the device to go to thermal regulation.
In each of these events, the timer is clocked with half-frequency to extend the charger time by a factor of 2, and charger termination is disabled. Normal operation starts again after the device junction temperature decreases to less than (TJ(REG)) and the system load decreases to a level where enough current is available to charge the battery at the desired charge rate. This feature is enabled by default and can be disabled by resetting the DYNTMR bit in the CHGCONFIG2 register to 0b. Figure 14 shows a modified charge cycle with the thermal loop active.