Transient sensitivity computation in controlled explicit piecewise linear simulation

This paper presents a general method for computing transient sensitivities using both direct and adjoint methods in controlled explicit event driven s imulation algorithms that employ piecewise linear device models. Sensitivit y information provides first order assessment of circuit variability with r espect to design variables and parasitics, This information is particularly useful for noise analysis, timing rule generation, and circuit optimizatio n. Techniques for incorporating transient sensitivity into adaptively contr olled explicit simulation, a general piecewise linear simulator, are presen ted. Sensitivity computation includes algorithms to handle instantaneous ch arge redistribution due to the discontinuous conductance models of the piec ewise linear elements, and the loss of simulation accuracy due to the nonmo notonic responses in autonomous adjoint circuits with nonzero initial condi tions. Results demonstrate the efficiency and accuracy of the proposed tech niques.