Distortion free switched capacitor filter - uses scaled capacitor values in each stage to prevent overvoltage clipping in intermediate stages

All the capacitors of the filter which are connected to the output of each amplifier are scaled by a factor to limit the voltage to below the peak voltage. Increasing the values of the capacitors of a stage reduces the voltage across each capacitor but the charge transferred remains the same. To calculate the scaling the peak voltage output of each stage is first calculated and the capacitors multiplied in value by the ratio of the calculated peak value to the peak permitted value. Each filter stage includes an operational amplifier of which the positive input is earthed. A network of resistors and capacitors is associated with each amplifier, and the resistors may pref. be replaced by MOS transistor switched capacitors. LA PRESENTE INVENTION CONCERNE UN PROCEDE D'ELIMINATION DES SURTENSIONS DANS UN FILTRE A CAPACITES COMMUTEES.CE PROCEDE COMPORTE DEUX ETAPES:-ON RELEVE LES TENSIONS EN SORTIE DE CHAQUE AMPLIFICATEUR, DANS LA BANDE PASSANTE DU FILTRE, ET EN PARTICULIER LA TENSION MAXIMALE V DE CHAQUE AMPLIFICATEUR A;-ON MODIFIE LES VALEURS DES CAPACITES RELIEES, PERIODIQUEMENT OU EN PERMANENCE, A LA SORTIE DE CHAQUE AMPLIFICATEUR EN LES MULTIPLIANT PAR UN COEFFICIENT K TEL QUE V1KV, OU V REPRESENTE LA TENSION DE SORTIE MAXIMALE QUE PEUVENT DELIVRER LES AMPLIFICATEURS OPERATIONNELS DU FILTRE, POUR UNE TENSION D'ALIMENTATION DONNEE, SANS DISTORSIONS GENANTES. AINSI LES MAXIMUM DES TENSIONS V, V, V EN SORTIE DES AMPLIFICATEURS SONT EGAUX A V DANS LA BANDE PASSANTE DU FILTRE.APPLICATION AUX FILTRES A CAPACITES COMMUTEES.