Empirical Analytical Inductance Calculation and Inductance to DC Resistance Ratio Optimization of On-Chip Solenoid Magnetic-Core Inductors

In this paper, two empirical analytical formulas are proposed for inductance calculation of on-chip solenoid magnetic-core inductors. Compared with traditional formula, the percentage of samples achieving within 10% accuracy (compared with simulation results) is greatly improved from 17% to 94% and 65% using the proposed formulas. Based on analytical inductance calculation, on-chip solenoid magnetic-core inductors are then systematically analyzed for inductance to dc resistance ratio optimization. Results show that a magnetic core length to width ratio of over 10 is preferred. The impacts of inductance value and device area are also studied. The analytical calculation agrees well with numerical simulation, and is useful for design optimization.