The junction temperature (T_J) of the device is monitored by an internal temperature sensor. If T_J exceeds 170°C (typical), the device goes into thermal shutdown. Both the high-side and low-side power FETs of both converters are turned off and PG goes low. When T_J decreases below the hysteresis amount of typically 20°C, the converters resume normal operation, beginning with soft start. When both converters are in a PFM pause, the thermal shutdown is not active. After the 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. As long as one converter is in PWM, thermal shutdown is always active.