Here is a great application note from Maxim describing the process of designing a high voltage LED driver. The guide goes step by step so it’s easy to follow it.
This application note details a step-by-step design process for the MAX16833 high-voltage high-brightness LED driver. This process can speed up prototyping and increase the chance for first-pass success. A typical design scenario is presented, along with example calculations based on the design constraints. Component selection trade-offs are discussed. A spreadsheet calculator is included to help calculate external component values. This application note focuses on the boost converter topology. However, the same process can be applied to other topologies as long as the underlying equations are understood.
Step-by-Step Design Process for the MAX16833 High-Voltage High-Brightness LED Driver - [Link]