CMOS Operational Ampli er Design and Optimization via Geometric Programming

| We describe a general method for optimized design of CMOS operational ampli ers. We observe that a wide variety of design objectives and constraints have a special form, i.e., they are posynomial functions of the design variables. As a result, the ampli er design problem can be expressed as a special form of optimization problem called geometric programming, for which very e cient global optimization methods have been developed. As a consequence, we can e ciently determine globally optimal amplier designs, or globally optimal tradeo s between competing performance measures such as power, open-loop gain, and bandwidth. Our method, therefore, yields completely automated synthesis of (globally) optimal CMOS ampli ers, directly from speci cations. In this paper, we apply this method to a speci c common two-stage ampli er architecture. We compute globally optimal tradeo curves relating performance measures such as power dissipation, crossover frequency, and open-loop gain.