The power grid transient simulation in linear time based on 3-D alternating-direction-implicit method

The rising power consumption and clock frequency of very large scale integration technology demand robust and stable power delivery. Extensive transient simulations on large-scale power delivery structures are required to analyze power delivery fluctuation caused by dynamic IR drop and Ldi/dt drop as well as package and on-chip resonance. In this paper, we develop a novel and efficient transient simulation algorithm for the power distribution networks. Our algorithm, three-dimensional (3-D) transmission-line-modeling alternating-direction-implicit (TLM-ADI) method, first models the power delivery structure as 3-D transmission line shunt-node structure and transfers those equations to the telegraph equation. Finally, we solve it by the alternating direction implicit method. The 3-D TLM-ADI method, with linear runtime and memory requirement, is also unconditionally stable, which ensures that the time steps are not limited by any stability requirement. Extensive numerical simulation results show that the proposed algorithm is not only over 300 000 times faster than SPICE but also extremely memory saving and accurate.