Abstract: An equivalent circuit is capable of, while having a simple configuration, accurately expressing a superposition characteristic and having excellent practicality and workability. A current sensor and a voltage source are connected in series between external terminals of an equivalent circuit. A reference state element having an impedance forms a closed loop with a current source. A current flowing through the equivalent circuit and detected by the current sensor is reproduced by the current source and then applied to the reference state element, so that a potential difference is generated across the reference state element. A voltage obtained by multiplying the potential difference by a correction coefficient is outputted by the voltage source. By setting the correction coefficient to be dependent on the current or an inter-terminal voltage, the impedance represented by the equivalent circuit can be reproduced as a characteristic dependent on the current I or the inter-terminal voltage.

Abstract: An equivalent circuit is capable of, while having a simple configuration, accurately expressing a superposition characteristic and having excellent practicality and workability. A current sensor and a voltage source are connected in series between external terminals of an equivalent circuit. A reference state element having an impedance forms a closed loop with a current source. A current flowing through the equivalent circuit and detected by the current sensor is reproduced by the current source and then applied to the reference state element, so that a potential difference is generated across the reference state element. A voltage obtained by multiplying the potential difference by a correction coefficient is outputted by the voltage source. By setting the correction coefficient to be dependent on the current or an inter-terminal voltage, the impedance represented by the equivalent circuit can be reproduced as a characteristic dependent on the current I or the inter-terminal voltage.

Abstract: In a capacitor equivalent circuit model for when a DC voltage is superimposed on a signal, using an equivalent circuit for when the DC voltage is not applied as a baseline, a voltage-controlled current source or voltage source that adjusts the signal in accordance with the superimposed DC voltage is substituted with a portion that represents the capacitance of the equivalent circuit. The voltage-controlled current source or voltage source is then modeled using a current or voltage approximation formula that describes the change in the signal resulting from the changes in the characteristics of the capacitor due to superimposition of the DC voltage, and a device that represents the capacitance of the equivalent circuit behaves similar to a variable device due to superimposition of the DC voltage. This approximation formula reduces computational load on a simulator and prevents issues such as divergence.