Point of Load Regulation
Point of load regulation has been used in electronic systems for many years. You can easily find that in radio receivers it is a common practice to isolate sensitive loads from power supply noise. And dedicated point of load regulators have been a necessity in military and aerospace applications where modularity and sub circuit isolation are required for reliability, serviceability and low susceptibility to interference.
The current generation of digital televisions presents several challenges to the power designer, while focusing on the benefits of using a point-of-load power architecture can add design flexibility. For example, many set-top-boxes are flat-panel designs consisting of individual modules in separate locations. These modules may consist of tuner units, main system boards, display drivers, audio sub-systems, and other components. Each of these sub-systems can contain sensitive analog circuits, processors, application specific integrated circuit and other circuitry, each with their own unique power requirements. The voltage of alternating current line is converted to an intermediate bus voltage and then routed to each module within the set. This voltage is typically in the range of 12 to 15V direct current. Point-of-load regulators in each module are used to convert this intermediate bus voltage to the voltages required by the individual components.