INTO-OA: Interpretable Topology Optimization for Operational Amplifiers

This paper presents INTO-OA, an interpretable topology optimization method for operational amplifiers (op-amps). We propose a Bayesian optimization-based approach to effectively explore the high-dimensional, discrete topology design space of op-amps. Our method integrates a Gaussian process surrogate model with the Weisfeiler-Lehman graph kernel to extract structural features from a dedicated circuit graph representation. It also employs a candidate generation strategy that combines random sampling with mutation to balance global exploration and local exploitation. Additionally, INTO-OA enhances interpretability by assessing the impact of circuit structures on performance, providing designers with valuable insights into generated topologies and enabling the interpretable refinement of existing designs. Experimental results demonstrate that INTO-OA achieves higher success rates, a 1.84× to 19.10x improvement in op-amp performance, and a 3.20x to 14.33× increase in topology optimization efficiency compared to state-of-the-art methods.