To overcome the design and performance challenges of high step-down DC-DC converters, a novel quadratic step-down converter is developed using an unorthodox approach of topology superimposition. The resulting superimposed quadratic buck (SQB) converter utilizes minimal component count while delivering power in parallel paths and minimizing RMS current for high efficiency. The converter on-time is substantially extended thanks to its quadratic conversion ratio, while the output ripples are largely reduced by inductor current ripple cancellation techniques. An experimental prototype delivers a maximum load of 20A with a 94.5% peak efficiency in direct 48V/1V conversion.
