The junction temperature (T_J) of the device is monitored by an internal temperature sensor. If T_J exceeds 170°C (typ), the device goes into thermal shutdown. Both the high-side and low-side power FETs are turned off and PG goes low. When T_J decreases below the hysteresis amount of typically 15°C, the converter resumes normal operation, beginning with soft start. During PFM, the thermal shutdown is not active.