System for designing and testing a sigma-delta modulator using response surface techniques

A method of designing an analog-to-digital device by determining the non-linearity and non-ideality of the design, the design having at least one integrator design model, a respective non-linear integrator design model, and non-linearity coefficients, said method comprising the following steps:

• generating a model data set from a plurality of simulations of the analog-to-digital design employing the respective non-linear integrator design model wherein the non-linear design model comprises at least one polynomial equation;
• generating an n-dimensional prediction equation corresponding to said model data set;
• measuring the input response of each respective non-linear integrator design model to generate a respective input response test data set;
• generating a plurality of numerical values for the non-linearity coefficients in the respective non-linear design model from said respective test data set;
• and
• determining the acceptability of the analog-to-digital design by solving said prediction equation using said plurality of numerical values as input values.

An apparatus for determining the non-linearity and non-ideality of an analog-to-digital device under test, the device under test having at least one integrator, a respective non-linear integrator model, and non-linearity parameters, said apparatus comprising:

• means for generating a model data set from a plurality of simulations of the analog-to-digital device under test employing the respective non-linear integrator model wherein the non-linear integrator model comprises at least one polynomial equation;
• means for generating an n-dimensional prediction equation corresponding to said model data set;
• means for measuring the input response of each respective non-linear integrator to generate a respective input response test data set;
• means for generating a plurality of numerical values for the non-linearity coefficients in the non-linear integrator model from said respective test data set;
• and
• means for determining the acceptability of the analog-to-digital device under test by solving said prediction equation using said plurality of numerical values as input values.