The RD-157 reference design board is a USB charger with an average active efficiency of 73.9%, exceeding the Energy Star 2 standard. This design also provides a no-load energy consumption of 28 mW with an input voltage of 120 VAC, and 32 mW with an input voltage of 230 VAC. This is also better than the Energy Star 2 requirement of < 300 mW no-load energy consumption.