Pseudo transient analysis method of direct current operating point of nonlinear circuit and device

Abstract

The invention relates to a pseudo transient analysis method of a direct current operating point of a nonlinear circuit and a device. The analysis method comprises the following steps: a PN node of each MOS pipe in the nonlinear circuit is connected with a parallel conductance in parallel, and a bypass conductance and a bypass capacitance are connected between each node of the MOS pipe and the ground; the initial values of the parallel conductance and the bypass conductance are set to be more than a predetermined default value; zero setting is carried out to all independent sources; the values of the independent sources are gradually rose to the original value of the independent sources within a specific multiple time of a time constant formed by the bypass conductance and the bypass capacitance; the iteration is carried out in a manner of gradually reducing the bypass conductance until the bypass conductance is finally and completely eliminated; the iteration is carried out in a manner of gradually reducing the parallel conductance until the parallel conductance is equal to the default value predetermined by the parallel conductance; the transient analysis is continuously carried out, and whether the current of the bypass capacitance is smaller than a given error is checked to judge whether the pseudo transient analysis is finished.

Description

technical field [0001] The invention relates to a nonlinear circuit analysis method and device, in particular to a pseudo-transient analysis method and device for a DC operating point of the nonlinear circuit. Background technique [0002] The circuit simulation software (Simulation Program with Integrated Circuit Emphasis, HSPICE) needs to perform DC analysis before performing any form, so as to establish the DC bias point of the circuit. With this as a starting point, other performance simulations such as transients, AC small signals, and noise can be performed. The essence of the calculation of the DC operating point of the circuit is to solve a nonlinear algebraic equation system in mathematics. In order to establish the DC analysis point of the circuit, HSPICE must solve a set of nonlinear equations describing the behavior of the circuit, which can be numerically solved by commonly used nonlinear algebraic equations: direct Newton-Raphson Algorithm (N-R algorithm) , c...

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Problems solved by technology

However, the pseudo-transient method increases the probability of oscillation due to the addition of pseudo-inductance and pseudo-capacitance during the simulation, resulting in a situation that takes more time to converge or is difficult to converge, and after these steps, the node voltage or The current may still not converge causing the simulation to break

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