This paper presents a systematic methodology for developing structural macromodels expressing the linear and weakly nonlinear performance of analog circuits. The models are in the frequency domain. The methodology includes two steps. First, building-block behavioral (BBB) concept is used to describe the basic building blocks of a circuit, and a decoupling technique is used to generate uncoupled BBB structural circuit models. Then, a nonlinear system is represented as a system with nonlinear inputs and linearly coupled blocks, and the linear couplings are removed. Experiments are offered for single-stage OpAmp, three-stage OpAmp, and operational transconductor amplifier (OTA) circuits. The produced models are tunable for the required accuracy, offer insight into the circuit operation, and offer simulation time speedup as compared to SPICE simulation.

This paper presents a systematic methodology for producing reconfigurable ΔΣ modulator topologies with optimized flexibility in meeting variable performance specifications. To increase their flexibility, topologies are optimized for performance attributes pertaining to ranges of values rather than being single values. Topologies are implemented on switched-capacitor reconfigurable mixed-signal architectures. As the number of configurable blocks is very small, it is extremely important that the topologies use as few blocks as possible. A case study illustrates the methodology for specifications from telecommunications area

This paper proposes a systematic methodology for designing reconfigurable continuous-time DeltaSigma modulator topologies. Topologies are optimized by minimizing the complexity of the topologies, maximizing the sharing of circuits between the different modes, maximizing the topology robustness with respect to circuit nonidealities, and minimizing the total power consumption. This paper presents a case study for designing topologies for a three-mode reconfigurable DeltaSigma modulator and compares the obtained topologies with a state-of-the-art design and topologies obtained using the DeltaSigma Toolbox

This paper presents a systematic methodology for developing structural nonlinear macromodels for analog circuits. The methodology includes two steps: first, a nonlinear system is represented as a system with nonlinear inputs and linearly coupled blocks. Then, the linear couplings are removed. The methodology also uses a novel description of circuit nonlinearities as a successive composition of three operators. The generated nonlinear models are scalable, tunable according to the required accuracy, and offer insight into the circuit operation.

This paper proposes a methodology for designing reconfigurable continuous-time DeltaSigma modulator topologies. The methodology is based on the concept of generic topology that expresses all possible signal paths in a reconfigurable topology. Topologies are optimized for minimizing the complexity of the topologies, maximizing the sharing of circuitry for different modes, maximizing the topology robustness with respect to circuit nonidealities, and minimizing total power consumption. The paper presents a case study for designing topologies for a three mode reconfigurable DeltaSigma modulator, and compares topologies with state-of-the-art design

The design of reconfigurable DeltaSigma modulators requires cumbersome circuit-level simulations. Besides the challenges inherent to high-performance analog-to-digital converter (ADC) design, the gap between system-level specification and circuit-level implementation makes the design even more difficult and inefficient. Circuit macromodels are an efficient way of tackling these problems by speeding up simulation and offering insight into circuit design. This paper presents a library of structural macromodels customized for cells used in DeltaSigma modulator design. We present original structural macromodels for two operational amplifier (opamp) and one operational transconductor amplifier (OTA) circuits. These cells are used to implement the loop filter in continuous-time DeltaSigma modulators. The proposed library helps the designer capture circuit-level constrains and tradeoffs before doing circuit implementation. It also makes top-down design of analog circuits more efficient by meaningful abstracting circuit-level parameters to a higher design level

This paper presents a systematic methodology to create customized structural macromodels for a specific analog circuit. The novel contributions of the method include definition of the building block behavioral concept and two original algorithms to generate structural models. Experiments are offered for two-stage opamp and operational transconductor amplifier (OTA) circuits. The automatically produced models are accurate, offer design insight, and require low modeling effort.

The paper proposes a novel architecture synthesis algorithm for single-loop single-bit /spl Delta//spl Sigma/ modulators. We defined a generic modulator architecture and derived its noise and signal transfer function (NTF/STF) in symbolic forms. We then used the TF in MINLP (mixed integer nonlinearly constrained programming) to generate optimal topologies for a variety of design requirements, such as modulator complexity, sensitivity and power consumption, which appeared as cost functions. Experiments show the superiority of the synthesized topologies as compared to traditional solutions.