Investigation and Optimization of Spiral Inductor Design for On-Chip Buck Converter

摘要

This paper introduces the design of a square shape spiral inductor to replace the floating inductor in a buck converter (switching voltage regulator). A feasibility study of the on-chip implementation of the spiral inductor for the integration of the buck converter is presented. Thepaper also investigates the impacts of the electrostatic and electromagnetic interference within the spiral inductor structure. Inductor is the primary bottleneck of the on-chip implementation of a switching regulator. Since inductors require large chip area and exhibit various parasitic issues,inductors are normally implemented off-chip or fabricated as part of the package. The paper focuses on the on-chip implementation of the spiral inductor and the effects of capacitive and inductive coupling noises inside the spiral inductor. For next generation on-chip voltage regulator, asolution to minimize these coupling noises due to the parasitic effects that are prominent at high frequency are presented. The simulation results are verified using ANSYS Q3D simulator. The skin effect related parasitic problem is also investigated. In addition, a comparative analysis ofthe performance of Copper (Cu), Aluminum (Al), and Carbon Nanotube (CNT) based spiral inductors is performed.