As the use of smart electronic gadgets increases in our lives, we have grown used to having them available for use at any instant necessary. Nowadays, no one is ready to switch on a piece of equipment and wait for it to become operational—we need them instantly on and active. This functionality means the equipment must remain always on, consuming power.
However, this posed an additional problem for battery-powered equipment, as the always-on status drained batteries very fast. Therefore, the design of electronic equipment required a standby status, which reduced its power consumption to a substantially low level. This standby power loss is also known as vampire power loss.
Considering the total number of electronic equipment each one of us uses at home, at the office, on the move, etc., the total amount of vampire power loss is a substantial amount, enough to strain our infrastructure at the power level, while costing people and businesses lost money in wasted energy. This is largely on account of electronic devices being constantly connected and being on standby when not in direct use.
For instance, a legacy consumer product like a TV set, could consume upwards of several hundred dollars every year. Almost all modern products can waste money. That means an apartment building may be wasting thousands of dollars a year on products only waiting for their owners to use them. This not only affects operating costs but also impacts performance aspects like power factor corrections to every home.
Energy Star, an initiative of the US DOE or Department of Energy and the US Environmental Protection Agency program is addressing this issue. One can find the Energy Star label on over 75 certified product categories at homes, commercial buildings, and industrial plants. Another is the EU Directive 92/75/EC, which established a labeling scheme of energy consumption—mostly for white goods, cars, and televisions—that must display an EU Energy Label.
Design engineers are addressing this vampire power loss in two ways—a top-down approach, and a bottom-up approach. The top-down approach uses advanced circuit topology that is microcontroller-based. The microcontroller manages closely each on-chip peripheral and shuts down any unnecessary components like the display driver when entering standby mode. However, this strategy is useful in larger circuits, where there are many non-essential subsystems to be powered down when not in use.
Although the top-down approach is necessary and important, this is mostly a reactive approach. The method’s address of energy consumption is based on its power circuit. If the power circuit is not effective, the overall performance of the system remains limited.
On the other hand, the bottom-up approach begins with the power electronic components on the board. In this approach, operating at a higher efficiency level and using advanced subsystem power management has a much better effect when using a low standby power baseline. Using a system with better efficiency at its base level, the designer can effectively leverage several circuit-optimization methodologies. For instance, modern switching transistors offer performances that bring a cascading benefit to the rest of the subsystem.
