A bias-driven approach for automated design of operational amplifiers

This paper presents a transistor-level automation to perform component sizing, power optimization and layout generation for fully-differential operational amplifiers (op-amps). The design variables of the component sizing are bias voltages and bias currents. The free space of the variables is easy to be restricted by circuit constraints. A lookup-table-based scheme is presented to translate the variables into transistor dimensions without much preparing effort. The layout generation employs analog layout skills, such as device matching, dummy cell and guard ring, to have good quality.