Comparison of Custom-Designed Converters and RECOM R1SX

Another significant advantage that specialized suppliers bring to converter modules is their high efficiency and outstanding reliability, proven in thousands of applications. Modern designs often require a large number of converters, so developers are advised to pay close attention to the energy efficiency of each such component. Large converters typically operate at energy efficiency ratings exceeding 90%, a level that is difficult to achieve with smaller DC/DC converters in the 1W to 2W range, as each converter has a fixed quiescent power dissipation, and this dissipation ratio is relatively higher for smaller converters than for larger ones. Therefore, depending on the actual power and topology, the energy efficiency of an optimized DC/DC converter is approximately 85% to 92%. However, in this case, focusing solely on the absolute rated energy efficiency at full load without considering the energy efficiency at lower load ranges can be risky. Generally, all converters achieve their highest energy efficiency when operating close to their rated load. The lower the load, the lower the energy efficiency. However, well-designed converters maintain consistently high energy efficiency, especially in the critical medium to low load range. The new, fingernail-sized R1SX-0505 1W converter was tested and compared to a custom converter of the same power rating, revealing a significant difference in energy efficiency. At full load, the custom design achieved an acceptable efficiency of approximately 70%. However, at half load, efficiency dropped to just over 55%, while the RECOM module achieved 72% efficiency even at half load, a difference of 17 percentage points. The custom device had a power loss of 409 mW, more than double that of the R1SX's 195 mW. In this case, choosing the "off-the-shelf" module not only reduced energy consumption but also lowered the thermal load on the PCB.