A Theoretically Sound Approach to Analog Circuit Sizing

Abstract

We consider the problem of determining the sizes of electrical components in analog circuits, such as operational amplifiers, that maximize a primary performance measure while satisfying some conditions on secondary performance measures. We propose a method that uses a circuit simulator, such as SPICE, to evaluate the performance measures exactly and updates the sizes of the electrical components iteratively using an optimization procedure, which is a variant of the Lagrangian method. The proposed approach guarantees convergence to a local optimal solution under mild conditions. Numerical results demonstrate that the proposed method finds optimal sizes successfully in various circuits including one-stage and two-stage operational amplifiers, a voltage-controlled oscillator, and an inverter chain.