Patent ID: 6081560
Filing Date: 2000-06-27
Classification: H04L

Abstract:
A circuit arrangement for generating a control signal for a controllable oscillator of a receiving device, said circuit arrangement being arranged to mix an FSK modulated input signal having at least two predetermined input frequencies with an oscillation supplied by the controllable oscillator, thus forming an intermediate frequency signal, as well as to derive from the intermediate frequency signal a data signal whose value follows from the frequency of the intermediate frequency signal (intermediate frequency), and to derive also a demodulator pulse signal whose frequency or phase is a measure of the frequency or the phase of the intermediate frequency signal, said circuit arrangement comprising a control signal generating branch for deriving the control signal from the demodulator pulse signal, an interrupt signal generating branch for deriving an interrupt signal from the data signal during the time intervals in which the data signal changes its value, as well as an interrupt stage which suppresses the extraction of a value for the control signal from the demodulator pulse signal in response to the appearance of the interrupt signal.