SOLID POLYMER ALUMINUM CAPACITOR CHIPS IN DC-DC CONVERTER MODULES REDUCE COST AND SIZE AND IMPROVE HIGH-FREQUENCY PERFORMANCE By

The new, 125 °C, solid polymer aluminum (SPA) capacitors have performance advantages over other types of low ESR capacitors when used as output filters in DC-DC modules. The principal advantage of an SPA capacitor is that its ultra low ESR permits filtering in a DC-DC converter with fewer capacitors. This reduces the cost and size of the converter. Other advantages are ignition free, open circuit failure mode, better filtering from lower ESR, higher peak current capability and more rapid energy transfer. The new type is available as Cornell Dubilier Type ESRH. While SPA capacitors are inherently reliable, they do have a wear out mechanism. Entrapped moisture causes a steady increase in ESR. However, the new 125 °C version has eliminated most of the moisture entrapped during manufacturing and can provide an expected life of more than 10 years in typical, hot running, DC-DC modules. 1