The High Efficiency Portable Media Player (PMP) Docking Station reference design showcases National Semiconductor’s PowerWise® power converters, battery charging circuitry, audio drivers and display interface. The reference design saves more power by initiating a power-saving mode when the PMP is unplugged from the wall power, automatically reducing the maximum brightness of the display as well as the output power of the audio drivers. See Figure 1 which shows the power management and audio segments of the reference design. ..