Title :
Techniques for improving the accuracy of geometric-programming based analog circuit design optimization
Author :
Kim, Jintae ; Lee, Jaeseo ; Vandenberghe, Lieven ; Yang, Chih-Kong Ken
Author_Institution :
Dept. of Electr. Eng., Californica Univ., Los Angeles, CA, USA
Abstract :
We present techniques for improving the accuracy of geometric-programming (GP) based analog circuit design optimization. We describe major sources of discrepancies between the results from optimization and simulation, and propose several methods to reduce the error. Device modeling based on convex piecewise-linear (PWL) function fitting is introduced to create accurate active and passive device models. We also show that in selected cases GP can enable nonconvex constraints such as bias constraints using monotonicity, which help reduce the error. Lastly, we suggest a simple method to take the modeling error into account in GP optimization, which results in a robust design over the inherent errors in GP device models. Two-stage operational amplifier and on-chip spiral inductor designs are given as examples to demonstrate the presented ideas.
Keywords :
analogue circuits; circuit optimisation; convex programming; geometric programming; piecewise linear techniques; active device models; analog circuit design optimization; analog circuit synthesis; bias constraints; convex optimization; convex piecewise-linear function fitting; error reduction; geometric programming; monotonicity technique; nonconvex constraints; on-chip spiral inductor; operational amplifier; passive device models; Analog circuits; Circuit synthesis; Design automation; Design optimization; Estimation error; Inductors; Optimization methods; Robustness; SPICE; Spirals;
Conference_Titel :
Computer Aided Design, 2004. ICCAD-2004. IEEE/ACM International Conference on
Print_ISBN :
0-7803-8702-3
DOI :
10.1109/ICCAD.2004.1382695