The device includes a temperature sensor on each power FET and within the controller portion of the device to monitor the temperature of each FET (T_J,FET) and the temperature of the controller (T_J,CONTROLLER). There are two cases that the device will consider to be a thermal shutdown fault:

• Relative Thermal Shutdown (T_REL): T_J,FET – T_J,CONTROLLER > T_REL
• Absolute Thermal Shutdown (T_ABS): T_J,FET > T_ABS

If either the above faults occur, the relevant switch will be turned off. Each channel is turned off based on the measurement of the temperature sensor for that channel. As result, if the thermal fault is detected on only one channel, the other channel continues operation.

Relative Thermal Shutdown (T_REL)

A relative thermal shutdown event can occur when there is a large peak power event such as a short-to-ground event where the FET temperature (T_J,FET) quickly rises relative to the controller temperature (T_J,CONTROLLER). Once the relative temperature (T_J,FET – T_J,CONTROLLER) exceeds T_REL the relevant channel will be turned off.

Absolute Thermal Shutdown (T_ABS)

An absolute thermal shutdown occurs when the FET temperature (T_J,FET) rises above T_ABS. This can occur when a channel is subjected to long durations of overcurrent such as a permanent short use case. Once the FET temperature (T_J,FET) exceeds T_ABS the relevant channel will be turned off.