This document provides preliminary information on a new product under development or evaluation. The product is a high power 3-phase auxiliary power supply evaluation board based on L5991 and ESBT STC08DE150HV. It features an input voltage of 400Vac +/- 20%, output voltage 1 of 24V, 6.25A @ 90kHz, output voltage 2 of 5V, 0.075A @ 90kHz, auxiliary output voltage of 15V, 0.01A, maximum output power of 150W, efficiency greater than 85%, switching frequency greater than 90kHz, and standby switching frequency greater than 35kHz.