In this thesis, a custom 120A, 50V power converter board for a brush-less drone motor is designed as part of the Bachelor Graduation Project. The control and embedded systems parts of the project are handled by other subgroups. The power converter consists of three main parts: the inverter, the sensors and the low voltage DC to DC converters. These were implemented respectively with a triple half bridge controlled by high-/low-side gate drivers, analog current en voltage sensors, a digital temperature sensor, buck converters and an LDO. This thesis describes the design choices made for these parts and the development of a PCB temperature model. Two prototypes have been assembled and tested, showing the power converter works as intended. High voltage and current tests are still to be performed to ensure perfect operation. The temperature model yields figures that are high but realistic and the required active cooling has not been quantified. As a final note, the fully integrated ESC was able to make the motor spin at low speeds.