Operational amplifiers (op-amps) are widely used in circuit systems. The increasing complexity of the power supply network has led to the susceptibility of the power supply port to electromagnetic interference (EMI) in circuit systems. Therefore, it is necessary to investigate the electromagnetic susceptibility (EMS) of op-amps at the power supply port. In this paper, we assessed the effect of EMI on the operational performance of op-amps through the power supply port by a bulk current injection (BCI) method. Firstly, we conducted the continuous sine wave into the power supply port by a current injection probe and measured the change in the offset voltage under EMI. Secondly, we proposed a new method of conducted susceptibility and obtained the susceptibility threshold regularities of the op-amps at the power supply port under the interference of different waveform signals. Our study provided conclusive evidence that EMI reduced the reliability of the op-amp by affecting the offset voltage of op-amps and demonstrated that the sensitivity type of op-amps was peak-sensitive at the power supply port. This study contributed to a deep understanding of the EMS mechanism and guided the design of electromagnetic compatibility (EMC) of op-amps.

During circuit conduction immunity simulation assessments, the existing black-box modeling methods for chips generally involve the use of time-domain-based modeling methods or ICIM-CI binary decision models, which can provide approximate immunity assessments but require a high number of tests to be performed when carrying out broadband immunity assessments, as well as having a long modeling time and demonstrating poor reproducibility and insufficient accuracy in capturing the complex electromagnetic response in the frequency domain. To address these issues, in this paper, we propose a novel frequency-domain broadband model (Sensi-Freq-Model) of IC conduction susceptibility that accurately quantifies the conduction immunity of components in the frequency domain and builds a model of the IC based on the quantized data. The method provides high fitting accuracy in the frequency domain, which significantly improves the accuracy of circuit broadband design. The generated model retains as much information within the frequency-domain broadband as possible and reduces the need to rebuild the model under changing electromagnetic environments, thereby enhancing the portability and repeatability of the model. The ability to reduce the modeling time of the chip greatly improves modeling efficiency and circuit design. The results of this study show that the “Sensi-Freq-Model” reduces the broadband modeling time by about 90% compared to the traditional ICIM-CI method and improves the normalized mean square error (NMSE) by 18.5 dB.

This article addresses the challenge of modeling the conducted immunity of mixed analog-digital integrated Circuits under electromagnetic interference (EMI). We propose a black-box modeling method, integrated circuits for RF immunity behavioral simulation—conducted immunity modeling using particle swarm optimization and piecewise Volterra series [ICIM-CI(PSVIB)]. This method leverages particle swarm optimization (PSO) and piecewise Volterra Series to enhance the immunity behavior module of the ICIM-CI model, aimed at simulating RF immunity in integrated circuits for conducted immunity scenarios. The proposed model accurately describes the nonlinear behavior of integrated circuits using the piecewise Volterra series and significantly improves model accuracy and generality by optimizing the segmentation threshold with the PSO algorithm. This approach overcomes the limitations of traditional ICIM-CI models, which assume linearity and thus struggle to precisely capture the nonlinear response of mixed analog-digital integrated circuits under EMI. Additionally, the proposed model addresses deficiencies in quantitative sensitivity analysis, output of quantitative information, and parametric cascade simulation. Experimental results demonstrate that the ICIM-CI (PSVIB) model provides accurate quantitative sensitivity analysis, outputs comprehensive quantitative information, supports parametric cascade simulation, and exhibits high generality. Compared to the traditional ICIM-CI model, the normalized mean square error of broadband modeling improves by at least 7.3 dB.

The existing chip RF conduction immunity modeling method, integrated circuit immunity model conducted immunity (ICIM-CI), in mixed analog-digital integrated circuit (MADIC) is restricted by insufficient model nonlinearities, including large deviations between predictions and actual circuit performance under specific conditions, and the inability to carry out cascade quantization sensitivity simulations. This study presents an improved ICIM-CI modeling method, called ICIM-CI (nonlinear immunity behavior-NIB), which incorporates the concept of poly-harmonic distortion (PHD) to account for the conduction sensitivity of ICIM-CI in MADIC. This novel approach involves introducing multi-harmonic nonlinear coefficients into the immunity behavior (IB) module of the conventional ICIM-CI model, resulting in enhanced nonlinear characteristics of the IB module. The conventional ICIM-CI model can be improved from a binary judgment result model to a cascade simulation model with a nonlinear quantized output response. The proposed method can generate a broadband model on the conduction immunity of the chip in the frequency domain, and it supports cascade simulation. Measurements on a standard chip showed that compared with the traditional ICIM-CI method, the normalized root-mean-square error of this method is improved by 18.5 dB, while the modeling time is reduced by about 98%.