Power supply engineers are certainly familiar with optimizing the light-load efficiency of switching power supplies. In most cases, switching power supply designs are set at 70% to 80% load, especially since home appliances and consumer electronics are mostly in idle mode. However, the problem is that idle-mode losses account for a significant portion of the overall energy consumption. In this situation, achieving additional functionality while meeting the European (ErP) Directive 2009/125/EC presents a challenge.