Recently, Pareto-based multi-objective optimization methods are widely used in optimizing several complex engineering problems. In this paper, we present a Non-dominated Sorting based global optimization algorithm combined with novel efficient Constraint analysis to design ultra-low-voltage and low-power operational Transconductance Amplifiers (OTAs) for the application of LV, LP and medium speed biomedical analog to digital converters. Using Highlevel simulation-based multi-objective GA, several feasible optimal designs are achieved for a circuit topology in a given technology, considering process and temperature variations. The presented approach has lead to the significant reduction of the design time (nearly, 12 times the time required for weighted sum GA approach). To illustrate the effectiveness of this approach, a 0.5-V DTMOS-based Sub-threshold OTA has been designed in 0.18μm n-well CMOS process which consumes only 2.98μW power while having 95dB DC gain and 481 KHz GBW.

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