Design and optimization of package inductor for efficient power rail merger

The need of ultra-thin and light package form-factor pushes electrical solutions to a new height. In the past, package size grows with features and power increase from generation to generation. Following the launch of IPhone®, Ipad® and McBook Air®, many engineering community started to realize that big is not winning. Package size took a sharp reversal, and making the smallest possible form-factor with aggressive power scaling becomes the motto motivation to achieve design win. The paper discusses one of the techniques in achieving a smaller package form-factor design by eliminating redundant pins, adopting existing package structure to optimize power rail merger and introducing package inductor to provide the proper isolation needed which was previously done with adding pins on package.