The ISOW774x devices have multiple protection features to create a robust system level solution.

• The Enable DC-DC / FAULT protection feature (EN/FLT) can be used as either an input pin, to enable or disable the integrated DC-DC power converter, or as an output pin, which works as an alert signal if the power converter is not operating properly. In the /FAULT use case, an alert is reported if V_DD > 7 V, V_DD < 2.5 V, or if the junction temperature >170°C. When a fault is detected, this pin will go low, disabling the DC-DC converter to prevent any damage.
  Figure 9-4 EN/FLT Fault Pin Diagram

• An over-voltage clamp feature is present on V_ISOOUT which will clamp the voltage at 6 V, when VSEL = V_ISOOUT, or 4 V, when VSEL = GND2, if there is an increase in voltage seen on V_ISOOUT. It is recommended that the V_ISOOUT stays lower than the over-clamp voltage for device reliability.

• Over-voltage lock out on V_DD will occur when a voltage higher than 7 V is seen. The device will go into a low power state and the EN/FLT pin will go low.

• The device is protected against output overload and short circuit. Output voltage starts dropping when the power converter is not able to deliver the current demanded during overload conditions. For a V_ISOOUT short-circuit to ground, the duty cycle of the converter is limited to help protect against any damage.
• The device is protected against output overload and short circuit. Output voltage starts dropping when the power converter is not able to deliver the current demanded during overload conditions. For a V_ISOOUT short-circuit to ground, the duty cycle of the converter is limited to help protect against any damage.
• The device is protected against output overload and short circuit. Output voltage starts dropping when the power converter is not able to deliver the current demanded during overload conditions. For a V_ISOOUT short-circuit to ground, the duty cycle of the converter is limited to help protect against any damage.
• 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 temperature goes above 165°C, thermal shutdown activates and the primary controller turns off which removes the energy supplied to the V_ISOOUT load, which causes the device to cool off. When the junction temperature goes below 150°C, the device starts to function normally. If an overload or output short-circuit condition prevails, this protection cycle is repeated. Care should be taken in the design to prevent the device junction temperatures from reaching such high values.