This board implements an offline power converter based on a single stage high-PF flyback topology using the HVLED001A controller. A very slim form factor is achieved with innovative magnetic componentry. The output voltage is controlled by the primary side, thus reducing the need for costly opto-couplers. The HVLED001A PSR precision and the innovative structure of the transformer makes for highly accurate output voltage regulation against load and line changes. A very high efficiency is obtained and a full set of protections including output short circuit and input overvoltage is included. Power factor and THD are optimized to be respectively higher than 0.95 and lower than 10% at full load over the entire input voltage range. The main application for this converter is for bus power supplies in a LED string driver providing 4 kV isolation.