# FUBOCO: Structure Synthesis of Basic Op-Amps by FUnctional BlOck COmposition

arXiv: https://arxiv.org/abs/2101.07517 · HTML: https://mlsanity.com/paper/2101.07517/

## Key facts

- Cited by 2 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 19 Jan 2021.

## Built on by (most cited first, 2 of 2)

- [AMSnet-KG: A Netlist Dataset for LLM-based AMS Circuit Auto-Design Using Knowledge Graph RAG](https://mlsanity.com/paper/2411.13560/) (2024)
- [GENIE-ASI: Generative Instruction and Executable Code for Analog Subcircuit Identification](https://mlsanity.com/paper/2508.19393/) (2025)

## Abstract (arXiv)

This paper presents a method to automatically synthesize the structure of an operational amplifier. It is positioned between approaches with fixed design plans and a small search space of structures and approaches with generic structural production rules and a large search space with technically impractical structures. The presented approach develops a hierarchical composition graph based on functional blocks that spans a search space of thousands of technically meaningful structure variants for single-output, fully-differential and complementary operational amplifiers. The search algorithm is a combined heuristic and enumerative process. The evaluation is based on circuit sizing with a library of behavioral equations of functional blocks. Formalizing the knowledge of functional blocks in op-amps for structural synthesis and sizing inherently reduces the search space and lessens the number of created topologies not fulfilling the specifications. Experimental results for the three op-amp classes are presented. An outlook how this method can be extended to multi-stage op-amps is given.