LED DRIVER DEMOBOARD INPUT 230VAC // OUTPUT 350MA, 40V (14W)

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.

Nominal input voltage for the DB1 is 120VAC, for the DB2 230VAC. Design for universal input (85 to 265VAC) is by all means possible but does increase cost and size while lowering efficiency. The input EMI filter was designed to suppress the differential mode switching noise to meet CISPR15 requirements. No specific components were added to suppress currents of common mode nature. Common mode current can be controlled in many ways to satisfy CISPR 15 requirements.