SLUSBL5A February 2015 – June 2019 UCC28730
The HV pin connects directly to the bulk capacitor to provide startup current to the VDD capacitor. The typical startup current is approximately 250 µA which provides fast charging of the VDD capacitor. The internal HV startup device is active until VVDD exceeds the turn-on UVLO threshold of 21 V at which time the HV startup device turns off. In the off state the HV leakage current is very low to minimize stand-by losses of the controller. When VVDD falls below the 7.7-V UVLO turn-off threshold the HV startup device turns on.