OASYS: a tool for aiding in design of high performance linear circuits

A circuit-optimization tool, OASYS, and the way it has helped in the design of high-performance linear circuits is discussed. Performance requirements may be conflicting in nature; improving one performance may degrade another performance or the circuit may be so complex that it is impossible to analyze it to obtain correct device sizes. These problems are faced in the design of TLE2027/37 op amps, where the goal was to maximize the gain bandwidth of the op amps while keeping the phase margin within the desired constraint limits. Conventional techniques had failed to do this in a reasonable amount of time. The methodology in OASYS is to use sensitivities (with regard to design parameters) generated by SPICE2 and the mini-max algorithm to tune the design parameters to achieve the desired goal. OASYS was used to optimize the performance of the TL2027/37 op amps. The OASYS methodology is described with special emphasis on the algorithms used. Results for the TLE2027/37 op amps predicted by OASYS and those extracted from the lab are compared to prove the accuracy of this tool