Thermal shutdown is active when the absolute temperature T_J > T_SD. When thermal shutdown occurs, the respective output turns off. The THER pin is used to configure the behavior after the thermal shutdown occurs.

• When the THER pin is low, thermal shutdown operates in the auto-retry mode. The output automatically recovers when T_J < T_SD – T_HYS, but the current is limited to I_{CL_TSD} or I_{CL_INTERNAL_TSD} (depending if the internal or external current limit is used) to avoid repetitive thermal shutdown. The thermal shutdown fault signal is cleared when T_J < T_{SD_RST} or after toggling the related ENx pin.
• When the THER pin is high, thermal shutdown operates in the latch mode. The output latches off when thermal shutdown occurs. When the THER pin goes from high to low, thermal shutdown changes to auto-retry mode. The thermal shutdown fault signal is cleared after toggling the related ENx pin.

Thermal swing activates when the power FET temperature is increasing sharply, that is, when ΔT = T_FET – T_LOGIC > T_SW, then the output turns off. The output automatically recovers and the fault signal clears when ΔT = T_FET – T_LOGIC < T_SW – T_HYS. Thermal swing function improves the device reliability when subjected to repetitive fast thermal variation. As shown in Figure 8-10, multiple thermal swings are triggered before thermal shutdown occurs.

Figure 8-10 Thermal Behavior Diagram