Procedural analog design (PAD) tool

This paper presents a new procedural analog design tool called PAD. It is a chart-based design environment dedicated to the design of analog circuits aiming to optimise design and quality by finding good tradeoffs. This interactive tool allows step-by-step design of analog cells by using guidelines for each analog topology. At each step, the user modifies interactively one subset of design parameters and observes the effect on other circuit parameters. At the end, an optimised design is ready for simulation (verification and fine-tuning). Furthermore, PAD provides a layout generator for matched substructures such as current mirror, cascode stage, differential pair, etc. The analog basic structures calculator embedded in PAD uses the complete set of equations of the EKV MOS model, which links the equations for weak and strong inversion in a continuous way. The present version of PAD covers the procedural design of transconductance amplifiers (OTAs) and different operational amplifiers topologies.