With rising fuel prices, increasing electrification, and imminent fines on CO2 emission within the EU, the requirement for energy and cost efficient supply concepts is becomingmore and more important in the automotive industry. This thesis presents an assessmentof, and improvement for energy and cost efficient power supply concepts for low-end automotiveand light e-mobility electronic control units, containing small µCs, and analogand logic components. Specifically, linear regulators, synchronous and non-synchronous buck converters, andswitched capacitor converters are investigated and assessed theoretically. The mostpromising concept, namely a discrete buck converter, is further studied using theoreticalassessment, experiment, and simulations. The key result of this work is a concept for replacing commonly used linear regulatorsin small electronic control units (ECUs) by a more efficient supply with only a smallcost adder. Specifically, since no low-end switched converter ICs are available today, wedeveloped a buck converter with discrete control circuit. This concept provides a cheap,yet efficient alternative to linear regulators for a wide range of applications. In addition,the application of this concept is supported by component selection criteria, and also bythe developed simulation models.