Feasible designs for high order switched-current filters

Fully balanced Euler integrators featuring S²I cells and common-mode rejection are used to realise ladder derived switched-current filters, based on modified left- and right-decomposition matrix methods. The usual problems of large silicon area, high sensitivity and component spreads, encountered in very high order designs, are overcome by minimising the input circuitry and by adopting modified approximation and prototype ladder manipulation techniques. The example of a 6th order modified left-UL bandpass filter demonstrates improved sensitivity, and a 21st order elliptic lowpass filter achieves a spread of 13.63, while preserving low passband sensitivity