A Practical Approach to Top/Down Analog Circuit Design

Since the advent of the behavioral modeling languages in the analog domain, a practical paradigm for Top/Down analog design bringing the benefits already found in the digital domain has been sought. The difficulty to harness the power of the behavioral modeling languages has however been a limiting factor to their widespread usage in the design flow. The approach presented in this paper combines a graphical access to the most commonly used behavioral funcitons and a framework-based integration supporting the Top/Down design paradigm in the analog domain with a clear design methodolgy. These three components are key to a practical Top/Down design, encompassing the system level study, the architectural and structural decisions, and the implementation and verification of the circuit using analog multi-level and mixed-signal simulations. The benefits of this approach are demonstrated in the Top/Down design of a phase-locked loop presented in this paper.