FD-MAGRPO: Functionality-Driven Multi-Agent Group Relative Policy Optimization for Analog-LDO Sizing

This paper introduces the Functionality-Driven Multi-Agent Group Relative Policy Optimization (FD-MAGRPO) algorithm, which is designed to enhance exploration efficiency in reinforcement learning (RL) for analog integrated circuit sizing. Our proposed method integrates two key innovations: (1) a critic-free multi-agent optimization framework based on Group Relative Policy Optimization (GRPO), that eliminates the critic network and achieves stable and efficient policy updates; and (2) a functionality-driven grouping strategy, that enables agents to coordinate exploration by functional roles instead of circuit blocks, thereby improving credit assignment and cooperation. Experimental results on practical low-dropout regulator (LDO) circuits with 65–179 design parameters show that the proposed method achieves rapid convergence with only 800–3000 simulations, yielding a 4.8×–13.0× speedup over state-of-the-art methods. Mathematical analysis and empirical studies validate that the combination of critic-free optimization and functionality-based grouping leads to higher exploration efficiency and faster convergence. The proposed method enables the discovery of higher circuit performances that are inaccessible to conventional approaches, establishing FD-MAGRPO as a robust and efficient solution for complex analog-LDO sizing tasks.