Method and apparatus for adjusting an active filter

A circuit arrangement for filtering an electrical signal, comprising:

• an active filter including at least one adjustable capacitor that determines frequency response;
• a circuit to determine a measure of the frequency response of the active filter;
• a memory arrangement which is adapted to store a plurality of adjustment parameters for adjusting the at least one adjustable capacitor, wherein the memory arrangement includes a table memory for storing digital values in binary form as adjustment parameters;
• and
• a control device which is adapted to select a stored adjustment parameter depending on said determined measure of the frequency response and on a nominal frequency response fed to the circuit arrangement and to adjust the at least one adjustable capacitor on the basis of the selected adjustment parameter,
• wherein the table memory includes an address word length having at least two digits, and the circuit arrangement fills at least one digit in the address word length with a digital value derived from the determined measure of the frequency response and fills at least one digit in the address word length with a digital value which describes the nominal frequency response.