AUTOMATIC SYNTHESIS OF OPERATIONAL AMPLIFIERS BASED ON ANALYTIC CIRCUIT MODELS.

Abstract

An automatic synthesis tool for CMOS op amps (OPASYN) is presented. The program starts from one of a number of op-amp circuits and proceeds to optimize various device sizes and bias currents to meet a given set of design specifications. Because it uses analytic circuit models in its inner optimization loop, it can search efficiently through a large part of the possible solution space. The program has a SPICE interface that automatically performs circuit simulations for the candidate solutions to verify the results of the synthesis and optimization procedure. The simulation results are also used to fine-tune the analytic circuit descriptions in the database. OPASYN has been implemented in Franz Lisp and demonstrated for three different basic circuits. Experiments have shown that OPASYN quickly produces practical designs that meet reasonable design objectives.