INTEGRATED CALIBRATION CIRCUIT AND A METHOD FOR CALIBRATION OF A FILTER CIRCUIT

摘要

Calibration circuit (10) and a method for calibrating an RC circuit of an integrated circuit (70) for calibrating a high-pass filter (11, 16), wherein the calibration circuit comprises: a filter arrangement (11, 16) comprising at least one tuneable filter (11) configured to filter an input signal (V1) having a predetermined frequency wherein the tunable filter (11) comprises at least two tuneable resistor elements (22, 23); a saturation detector (12) configured to detect saturation and non-saturation of the tuneable filter (11) by comparing a comparison voltage (V4) with the signal voltage of the filtered input signal (V2); a calibration control logic (13) configured to provide an incrementing counter signal (CI) and a decrementing counter signal (CD); wherein the calibration circuit (10) is further configured to set the comparison voltage (V4) to a first threshold voltage (Vth); to provide iteratively an incrementing counter signal (CI) to the filter (11) until saturation is detected; after saturation is detected, reducing the comparison voltage (V4) to a predetermined second threshold voltage (Vth/2) which is a predetermined value lower than the first threshold voltage (Vth); to provide then iteratively a decrementing counter signal (CD) to the filter (11) until non-saturation is detected. This invention further provides an integrated circuit, in particular a receiver circuit, a radar system and a calibration method.