OPTIMIZED SECOND AND FOURTH-ORDER OTA-C LP FILTERS

摘要

A general second-order low-pass OTA-C filter section is analyzed. Voltage noise spectral density and Schoeffler sensitivity are calculated. The design of the filter is performed in two ways, one based on simplicity of calculating filter elements and the other based on optimization. Optimization is done to decrease observed parameters: noise and sensitivity. The analyses results give a filter that gives lower sensitivity and noise. The optimization procedure is done for the fourth-order low-pass filter, as well. It is shown that decreasing one of the two parameters increases the other and a compromise has to be made in designing filter elements.