Mixed Frequency-Time Approach for Distortion Analysis of Switching Filter Circuits. Revision

摘要

Designers of switching filter circuits are often interested in steady-state and intermodulation distortion due to both static effects, such as nonlinearities in the capacitors, and dynamic effects, such as the charge injection during MOS transistor switching or slow operational amplifier settling. Steady-state distortion can be computed using the circuit simulation program SPICE, but this approach is computationally very expensive. Specialized programs for switched capacitor filters can be used to rapidly compute steady-state-distortion, but do not consider dynamic effects. In this paper, we present a new mixed frequency-time approach for computing both steady-state and intermodulation distortion. The method is both computationally efficient and includes both static and dynamic distortion sources. The method has been implemented in a C program, Nitswit, and results from several examples are presented. (RH)