Premium
A general approach to continuous‐time Gm‐C filters
Author(s) -
Koziel S.,
Szczepanski S.,
Schaumann R.
Publication year - 2003
Publication title -
international journal of circuit theory and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.364
H-Index - 52
eISSN - 1097-007X
pISSN - 0098-9886
DOI - 10.1002/cta.238
Subject(s) - topology (electrical circuits) , transfer function , filter (signal processing) , state space , mathematics , analogue filter , matrix (chemical analysis) , capacitor , state (computer science) , control theory (sociology) , digital filter , computer science , voltage , algorithm , engineering , electrical engineering , combinatorics , statistics , materials science , control (management) , artificial intelligence , composite material , computer vision
A general topology for transconductance‐capacitor ( G m ‐ C ) filters is presented that permits any continuous‐time analog G m ‐ C filter to be analysed via a matrix‐description. Based on these matrices, explicit formulas are derived for the transfer function and the sensitivities valid for any G m ‐ C filter topology. The approach leads to a useful relationship between the passive capacitor network of the filter and the degree of its transfer function. The matrix‐based approach is formulated especially for efficient use in computer‐aided analysis and design of Gm‐C filters, but ‘hand designs’ of G m ‐ C IFLF and LF filters are given as illustrative examples. A new, more general definition of G m ‐ C state‐space filters is proposed. Connections between the state matrices for voltage‐ and current‐mode state‐space G m ‐ C filters are formulated and two canonical transformations are defined that convert state‐space filters into direct state‐space ones, i.e. those having only grounded capacitors. Copyright © 2003 John Wiley & Sons, Ltd.