A Distributed Filter Within a Switching Converter for Application to 3-D Integrated Circuits

A design methodology for distributing a buck converter filter for application to 3-D circuits is described. The 3-D filter exploits transmission line properties, permitting the generation and distribution of power supplies to different planes. As compared to a conventional LC filter, the proposed filter only requires on-chip capacitors without the use of on-chip inductors. Additionally, the physical structure of the filter simultaneously enables the distribution of the current to the load while filtering the switching signal at the input. A case study in a 0.18- μm CMOS 3-D technology demonstrates the generation of a 1.2 V power supply delivering 700 mA peak current.