Researchers at the University of California, Davis have developed voltage converters systems – with associated control schemes – that span a broad spectrum of potential applications.
Switched-capacitor power converters are non-linear circuits that can transition quickly to another circuit configuration under certain conditions. For overall system efficiency reasons, switched-capacity power converters have not been used historically as part of high-density power solutions. More recently, switched-capacitor-inductor (LC) converters have demonstrated improved performance at high conversion ratios and found some appropriate applications in this space. Split-phase Dickson converters have been introduced in the literature which are efficient under heavy loads but which suffer increased component voltage stress with increasing conversion ratio ,. Additionally, like most conventional DC-DC converters, split-phase converters suffer reduced efficiency at light load due to maximized switch utilization.
Researchers at the University of California, Davis have developed a converter which leverages three key innovations to yield an improved solution:
First, this technology applies split-phase switching to a Cockcroft-Walton ladder variant; dramatically reducing voltage stress and allowing for a significantly smaller solution size.
Second, a new highly efficient clocking scheme, termed “N-Phase” switching, was developed for the exact same hardware and which offers improved light-load efficiency relative to split-phase switching due to its reduced switch utilization .
Lastly, this technology allows for optimal merging of switching between N-phase and split-phase control yielding the advantages of both. The control system automatically selects the most appropriate switching scheme based on the operating point and associated power load.
Since both N-phase and split-phase converters employ identical hardware, a control method that selects the optimal conversion technique for any operational environment provides the highest energy efficiency across a wide and variable load range. This technology thus has applications in mobile devices, aviation, biomedical markets and power distribution.