A Fast and Accurate Method of Redesigning Analog Subcircuits for Technology Scaling

In this paper, we present an efficient approach for technology scaling of MOS analog circuits by using circuit optimization techniques. Our new method is based on matching equivalent circuit parameters between a previously designed circuit and the circuit undergoing redesign. This method has been applied to a MOS operational amplifier. We were able to produce a redesigned circuit with almost the same performance in under 4 hours, making this method 5 times more efficient than convent iona l methods . representing the variance caused by the manufacturing process, source voltage, and temperature, and have capabilities of performing fast worst-case analysis; they are reasonable approaches for design in the actual working environment. But these models and the fast worst-case analysis are not precise enough to find the optimal design points for a very wide range of circuit parameters. Presently, we must use time-consuming circuit parameter optimization and worst-case analysis by circuit simulators like SPICE to obtain the required preciseness. Thus, more improvement is necessary. In this paper, we present an improvement of the automatic redesign method by fast circuit parameter optimization to make quick redesign of an operational amplifier possible. We describe problems of the conventional method and present the methodology for the improved method. We also describe the results obtained by applying this method to the redesign of an operational amplifier.