This paper presents a new method to automate the sizing of analog circuits. The method emulates the manual design procedure. The sizing task is formulated as a constraint programming problem. Two new algorithms are introduced: First, a hierarchical structural analysis of functional blocks that automatically sets up the analytical equations for the sizing. And second, a heuristic to guide the branching process of a constraint programming solver. We achieve a reproduction of the manual proceeding of designers and at the same time an automation of the set-up of the design problem, reducing the set-up effort to seconds. The method is primarily designed for operational amplifiers. More than 20 circuits, including different variants of two-stage, folded-cascode, telescopic and symmetrical op-amps, are considered at this time. This paper presents a runtime comparison of the newly developed branching heuristic with a generic branching heuristic on 20 different circuits. Furthermore, sizing results for a two-stage op-amp with transistors in weak inversion and a folded-cascode op-amp with common-mode feedback circuit are presented to show the effectiveness of the approach.

本文提出了一种自动调整模拟电路大小的新方法。该方法模拟手动设计过程。大小确定任务被公式化为约束编程问题。引入了两种新算法：首先，对功能块进行分层结构分析，该结构自动设置大小的分析方程式。其次，启发式方法指导约束编程求解器的分支过程。我们实现了设计师手动程序的复制，同时实现了设计问题的自动设置，从而将设置工作减少到几秒钟。该方法主要设计用于运算放大器。目前考虑的电路超过20种，包括两级折叠共源共栅，伸缩和对称运算放大器的不同变体。本文介绍了新开发的分支启发式算法与在20个不同电路上的通用分支启发式算法的运行时比较。此外，提出了具有弱反相晶体管的两级运算放大器和具有共模反馈电路的折叠共源共栅运算放大器的尺寸确定结果，以证明该方法的有效性。