Optimizing power consumption of embedded systems using smart power supply solutions
Power management is increasingly becoming an essential part in most of today's computer systems, focusing on the reduction of electric losses. Processor clock rates are lowered, core voltages are reduced and unnecessary peripherals are even turned off completely to reduce the power consumption during stand-by or light load scenarios. The proposed SmartPM principle introduces a further optimization utilizing an adjustable system supply voltage depending on the current power distribution. The physical background is a special characteristic of the numerous point-of-load (POL) DC/DC converters, since their efficiency does not only depend on the output current, but also on the input voltage. High load scenarios require high supply voltages to ensure low-loss power transmission while POL converters operate in a high efficiency range. In stand-by or under light load conditions, their efficiency drops significantly. Smart power supply solutions can reduce this influence by decreasing the system supply voltage in those scenarios. For this purpose, the system power supply has an additional communication interface that allows the computer system or an external power management unit to sweep the intermediate system and output voltage in order to identify the highest overall system efficiency. It also grants access to measured power consumption values for monitoring purposes.