A method for the evaluation of multirate sigma-delta systems

Simulation techniques for sigma-delta-based systems are discussed. An extension to the next state simulation method for block diagrams is presented which allows efficient handling of multirate systems. This is achieved by the additional definition of clock-dependent inputs for each element to define how the element behaves in a multirate situation. The algorithm has been encoded using the C language, under the UNIX operating system. The program has been used to evaluate many different topologies and has replicated the results of the purpose written programs used to analyze a third order cascade, a fourth order single loop ADC (analog-to-digital converter) and a converter with a multibit quantizer but with single bit feedback