A supercapacitor based enhancement technique for stand-alone surge protection circuits

With the International Technology Roadmap for Semiconductors predicting below-25nm feature-size VLSIs, powered by DC power supplies of less than 1V, protection against transients has become mandatory for modern electronic systems. Surge protection circuits are usually designed using non-linear devices such as metal oxide varistors and semiconductor devices and these devices are rated for short-term energy absorption, based on transient waveforms defined by standards such as IEEE C62.41. Despite their very low voltage DC ratings, supercapacitors are characterized by large time constants and significant continuous energy absorption ratings. This paper presents details of a patent-pending technique where multi-winding magnetic core with a supercapacitor based energy absorber stage can be combined with the commonly used non-linear devices, for enhanced protection. Comparison of the supercapacitor-enhanced circuit together with a commercial surge protection circuit is provided