INSIGHT: A Universal Neural Simulator Framework for Analog Circuits with Autoregressive Transformers

The compute-intensive nature of SPICE simulations hinders effective analog design automation. This paper introduces INSIGHT, a data-efficient, adaptive, high-fidelity, technologyagnostic universal neural simulator framework that formulates analog performance prediction as an autoregressive sequence generation task to accurately predict performance across diverse circuits. INSIGHT achieves test $\mathbf{R}^{\mathbf{2}}$ scores $\geq \mathbf{0. 9 5}$, outperforming existing neural surrogates. Cross-technology transfer learning experiments show that INSIGHT can preserve model performance with $\sim \mathbf{6 0 \%}$ less training data. Low-Rank Adaptation (LoRA) integration further reduces memory footprint by $\sim 42 \%$ and training time by $\sim 25 \%$, maintaining high performance. Our experiments show that INSIGHT-based RL sizing framework achieves $100-1000 \times$ lower simulation costs over existing sizing methods for identical benchmarks and target specifications.