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 by the hysteresis amount of typically 15°C, the device resumes normal operation, beginning with soft start. During a PFM pause, the thermal shutdown is not active. After a PFM pause, the device needs up to 9 µs to detect a too-high junction temperature. If the PFM burst is shorter than this delay, the device does not detect a too-high junction temperature.