A charge oriented mixed multirate method for a special class of index-1 network equations in chip design

Multirate methods make use of latency that occurs in electrical circuits to simulate more efficiently the transient behaviour of networks: different stepsizes are used for subcircuits according to the different levels of activity. As modelling is usually done by applying modified nodal analysis (MNA), the network equations are given by coupled systems of stiff differential-algebraic equations. Following the idea of mixed multirate for ordinary differential equations, a ROW-based 2-level multirate method is developed for index-1 DAEs arising in circuit simulation. To obtain order conditions, P-series are generalised to MDA-series for partitioned DAE systems.