Power supply circuit in an inverter for driving an electrical machine, method of operating the power supply circuit and safety control device

A power supply circuit in an inverter for driving an electrical machine includes a high-voltage branch, a low-voltage branch, a backup supply branch, an operating DC/DC converter, which is connected on the one hand to the high-voltage branch and on the other hand to the low-voltage branch, a backup supply DC/DC converter, which is connected on the one hand to the high-voltage branch and on the other hand to the backup supply branch, an inverter circuit for connecting the electrical machine to the high-voltage branch, and a safety control device which is set up to switch the inverter circuit to a safe state when a shutdown situation is present, wherein the inverter circuit and the safety control device are supplied with energy from the low-voltage branch, wherein the inverter circuit and the safety control device are additionally supplied or can be supplied with energy from the backup supply branch.