A high efficiency single-cell cascaded charge pump topology-the competitive alternative to inductive boost converters

A single cell, efficiency optimized switched capacitor converter is presented. By means of a "modified cascaded" topology which supports additional conversion ratios and an automatically conversion ratio alignment to the V/sub OUT//V/sub IN/-ratio an overall average efficiency above 80% and a peak efficiency close to 90% is achieved. A current-mode control helps to stabilize the operating voltage on the "flying" capacitors independent on the conversion ratio. This reduces current spikes on the input and output of the converter and keeps the output voltage glitch-free when the conversion mode is changed. To optimize the efficiency at light loads a current-saving "LinearSkip" control is implemented. The converter was realized, in a 10-Pin MSOP package and needs 5 tiny 1 uF ceramic capacitors to build a complete single cell to 3.3 V converter.