A precorrected-FFT method for simulating on-chip inductance

The simulation of on-chip inductance using PEEC-based circuit analysis methods often requires the solution of a subproblem where an extracted inductance matrix must be multiplied by a current vector, an operation with a high computational cost. This paper presents a highly accurate technique, based on a precorrected-FFT approach, that speeds up this calculation. Instead of computing the inductance matrix explicitly, the method exploits the properties of the inductance calculation procedure while implicitly considering the effects of all of the inductors in the layout. An optimized implementation of the method has been applied to accurately simulate large industrial circuits with up to 121,000 inductors and nearly 7 billion mutual inductive couplings in about 20 minutes. Techniques for trading off the CPU time with the accuracy using different approximation orders and grid constructions are also illustrated. Comparisons with a block diagonal sparsification method in terms of accuracy, memory and speed demonstrate that our method is an excellent approach for simulating on-chip inductance in a large circuit.