Summary

The HV9931 LED driver is primarily targeted at low to medium power LED lighting applications where galvanic isolation of the LED string is not an essential requirement. The driver provides near unity power factor and constant current regulation using a two stage topology driven by a single MOSFET and control IC. Triac dimming of this design is possible with the addition of some components for preloading and inrush current shaping.  The HV9931DB2 demoboard is designed for a fixed string current of 350mA and a string voltage of 40V for a load power of about 14W. The board will regulate current for an output voltage down to 0V.