Efficient and robust path tracing algorithm for DC convergence problem

Finding the initial operating point information is one of the major problems for circuit simulators. New techniques to overcome this problem are developed. To reduce the iteration count, a new method of maintaining the tangent line directionality without taking small steps is developed. Different embedding functions are shown to have different paths; by choosing a proper embedding function, it is possible to avoid the critical points. The technique is tested on a set of DC nonconvergence circuits ranging from a few to several thousands of transistors. The results show that this method is very robust