DEVICE AND METHOD FOR MEASURING THE FREQUENCY OF A SIGNAL CODED MODULATED CARRIER SIGNAL

摘要

A device (10) for measuring a frequency of an input signal (IN) that is expected to comprise a carrier signal (CS) either being unmodulated (CSU) or being modulated (CSM) according to a predefined signal coding comprises: means (9) for generating a measurement period (MP), an input signal counter (2) which is adapted to count edges of the input signal (IN) during the measurement period (MP), sampling means (4) which are adapted to detect whether the input signal (IN) contains edges, control means (7) which are adapted to read a count value (CNT_2) of the input signal counter (2) on expiration of the measurement period (MP) and to derive the frequency (FR) of the input signal from the count value (CNT_2) of the input signal counter (2), wherein the means (9) for generating a measurement period (MP) are adapted to extend the measurement period (MP) by a time period (EXT) during which the absence of edges in the input signal (IN) is detected.