7.4.11.3 Protections on RDM and RTZ pin Faults

Since RDM and RTZ pins are the critical programming pins for ZVS control, UCC28780 offers both open and short protections to those pins. After V_VDD reaches V_VDD(ON), a fixed voltage level is applied to the pin and the corresponding current level flowing out of the pin is sensed to detect the pin fault event. As a result, too small of a current represents the pin-open state, and too large of a current represents the pin-short state where the short current level is self-limited. When the fault event is identified, one UVLO cycle of VDD is triggered as the protection response.