Effective Analog/Mixed-Signal Circuit Placement Considering System Signal Flow

Placement is among the most critical steps in analog/mixed-signal (AMS) circuit layout synthesis. It implicitly determines the wiring topology and therefore has considerable impacts on post-layout parasitics and coupling. Existing analog placement techniques are mainly focusing on geometric constraints in analog building blocks. However, there yet lacks an effective way to consider the system-level signal flow for sensitive AMS circuits. Leveraging prior knowledge from schematics, we propose to consider the critical signal paths in automatic AMS placement and present an efficient framework. Experimental results demonstrate our proposed framework's efficiency and effectiveness with a 22.8% reduction in routed wire-length compared to state-of-the-art AMS placer and 10 dB improvement in the signal-to-noise-and-distortion ratio (SNDR) for an ADC.