What is your most pressing power supply design challenge today? What is that one thing your boss always asks for? How can you make your power supply cheaper, or smaller? How can your design be more efficient and create less heat?
If you’re considering these questions, you’re not alone. The cost/size/performance trade-off has been around for decades. It will always be around as long as we are still designing power supplies, but it’s also what drives innovation in the power-supply arena. What innovations are occurring today?
Cost: The integration of the power supply is not new. And it still makes sense most of the time. Including more functions inside the power-supply integrated circuit (IC) reduces the number of components in the bill of materials (BOM). This reduction decreases the time spent on the pick-and-place line during assembly, eliminates the costs associated with maintaining many components in a warehouse, and eliminates the cost of these components from the BOM cost.
What is new is what is being integrated. Modern DC/DC converters for portable applications like electronic point of sale (ePOS) devices and wearables integrate, in some cases, all of the components required for a given power supply. This integration includes not just small signal components like soft-start capacitors and loop-compensation passives, but the inductor and input and output capacitors.
Size: A primary driver of integration is not only cost but solution size. Smaller components are generally cheaper. This point is especially true of power-supply output filters. The easiest way to make the power supply’s output filter smaller is to increase the switching frequency. But this increases the losses, which lowers efficiency and creates excessive heat.
Performance: If performance is judged by efficiency and the corresponding heat generated, then it can be a real issue in ultra-small, high-power systems like solid state drives (SSDs) and tablets. There simply isn’t enough space to properly dissipate the heat generated, so the only solution is to create less heat by being more efficient. Power-supply IC vendors are creating ever-improving power-save modes and are even lowering switching frequencies (under some operating conditions) to get better efficiency. Furthermore, packaging technologies are improving to combine good thermal performance with better efficiency in a smaller size.
What’s your greatest power-supply design challenge these days? The technology is rapidly changing, so it’s critical to keep up with it and always look for the latest and greatest power supply for your current design. Applications engineers around the world like myself are ready to assist you in navigating through the trade-offs and compromises in every design to get you the best solution for your customers.