The present document relates to efficient DC/DC converters with a modular structure for providing different levels of output currents. A controller for controlling a power converter which is configured to convert electrical power at an input voltage into electrical power at an output voltage is described. The power converter comprises first and second inverter stages comprising high side switches and low side switches which are arranged in series between the input voltage and a reference voltage. The midpoints between the high side switches and the low side switches are coupled. The electrical power at the output voltage is drawn from the midpoint. The controller is configured to determine an indication of a requested level of the electrical power at the output voltage, and to activate or deactivate the second inverter stage based on the indication of the requested level of the electrical power at the output voltage.