The UCC33421-Q1 has under voltage protection feature to protect the part when overload condition occurs. If an overload or a short circuit occurs at VCC such that VCC < 0.9 ×VCC condition occurs, the converter will go into the duty cycle limit mode as in the soft-start operation then will shutdown after a certain deglitch time. The deglitch time is added to accommodate for any instantaneous overloading or short circuit conditions that might be removed quickly and normal operation can resume. Once the part shuts down, the part will attempt an auto-restart after 160ms. If the fault condition remains, the part will shutdown again and attempt another auto-restart.