Point-of-Load: One for All

The increase in worldwide energy prices together with the rise in operating expenses associated with electronic goods are becoming a larger portion of equipment and/or consumer goods purchasing decisions. Therefore, R&D engineers are continuously looking for ways to reduce the power consumption of their products. In the past, this was mainly true for battery-powered applications since efficiency heavily influences the operational run time of a device. However, this trend has expanded over recent years to include many off-line powered consumer goods. 'Green' has changed from a 'buzz word' to a market trend that needs to be addressed by today's power solutions. Most look for architectural changes or lower power technologies to incrementally improve the efficiency of their systems while maintaining or improving performance levels. In this article we will examine a DC/DC controller in conjunction with the latest generation of NexFET power MOSFETs to address the higher efficiency aspect with additional functionality to increase the overall performance.

There are many non-isolated DC/DC controllers on the market that can convert from a 3.3 V, 5 V or 12 V power rail down to a processor core voltage. Existing solutions that have worked well in the past may not meet the requirements of today's high-performance processors. With further integration and increased performance, processor core voltages are beginning to drop sub 1 V while their current consumption increases up to multiple amps. These advancements of process technology must be matched with readily available point-of-load solutions. We will address these challenges in greater detail in order to show the advantages of the latest controller and MOSFET technologies. These advanced products are able to support ceramic bulk, bypass and filtering capacitors, in rush currents, active EMI reduction to pass FCC approval specifications, tight voltage regulation accuracy and, and last but not least, the support of pre-charged capacitor banks during start-up. All while achieving high efficiency, a small form factor and increased reliability.