A Multi-objective Optimization Methodology Applied to the Low-power Cmos Operational Amplifiers

This paper presents a novel design methodology for optimizing the performance of CMOS op-amp topologies by using Multi-Objective optimization Methodology. This methodology is used to find the optimal transistor dimensions in order to acquire operational amplifier performances for analog and mixed signal circuit applications. The goal is to automatically determine the device size in order to meet the given performance specifications while minimizing the design time, Area, power and cost function. This strongly suggests that the approach is capable of determining the globally optimal solutions to the problem. Accuracy of performance prediction in the sizing program (implemented in MATLAB) is maintained. These operational amplifiers were simulated by using cadence virtuoso spectre circuit simulator in 0.18μm CMOS technology with power supply ±1.8v. In this paper six performances are considered i.e.., Open loop Gain(Av), Unity gain bandwidth(UGB), Phase Margin (PM), Slew rate(SR), Area(A) and Power consumption(Pc). Finally a good agreement is observed between the program optimization and electric simulation.