Thermal protection is also integrated to help prevent the device from getting damaged during overload and short-circuit conditions on the isolated output. Under these conditions, the device temperature starts to increase. When the silicon junction temperature T_j sensed at the primary side die goes above the threshold TSD_THR(typical 165°C), thermal shutdown activates and the primary controller turns off which removes the energy supplied to the V_ISO load, which causes the device to cool off. When the junction temperature drops approximately 27°C (TSD_HYST) from the shutdown point, the device starts to function normally. If an overload or output short-circuit condition prevails, this protection cycle is repeated. Make sure the design prevents the device junction temperatures from reaching such high values.