Title :
Switched-capacitor LDI lowpass filters with improved selectivity
Author_Institution :
Virginia Polytechnic Institute & State University, Department of Electrical Engineering, Blacksburg, USA
Abstract :
Generalised expressions are given for transfer functions of an extensive family of lowpass switched-capacitor LDI ladder filters with optimum equiripple (or maximally flat) passbands and an arbitrary number of transmission zeros at half the sampling frequency. These allow greater flexibility in the design and permit tradeoffs to be made among factors such as sampling frequency, element value spread and dynamic range. The previously studied LDI filters with monotonic stopbands can be recovered as degenerate special cases of the generalised ones presented here.
Keywords :
active filters; integrating circuits; ladder networks; low-pass filters; switched capacitor filters; transfer functions; active type; dynamic range; element value spread; ladder filters; lossless discrete integrator; lowpass filters; optimum equiripple passbands; sampling frequency; switched capacitor filters; transfer functions;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19860227
