Studies on design automation of analog circuits : performance metrics

Sammanfattning: The trend of today is to integrate large systems containing analog and digital circuits on a single chip. This has the advantages of decreased power consumption and cost. In order to reduce the design time for these systems, efficient design automation tools are required.In the digital domain, design automation tools are well developed and widely used in industry. Typically, the layouts of digital circuits are performed using design automation tool and a standard cell library. This is not the case in analog domain since a large number of performance metrics is required to characterize an analog circuit. Further, analog circuit design lack formal design methodologies. Typically, time-consuming manual trial-and-error approaches are used in the design process. Hence, more efficient analog design tools are needed.In this thesis, the design automation of analog circuits is addressed. The main focus is on implementing a tool, which determines the device sizes of a circuit that meet a certain specification within reasonable time. This is performed using an optimizer together with equations for the performance metrics.Key features of the tool are the use of accurate device models and automatic generation of equations for the performance metrics. Further, the tool is built in modules in order to ease experimentation and be able to exchanged modules with more efficient implementations. In the current version of the tool continuous-time CMOS amplifiers can be designed.The tool can also be used to explore the available design space to determine limitations and possible trade-offs. This also allows comparisons of several topologies in order to determine the best circuit for a given specification.A simple template-based layout generator has also been implemented. It allows interconnect parasitics to be taken into account during the design phase. Hence, the circuit will meet the specification after the layout is completed.