Method and apparatus for phase detection

Abstract

For the detection of a phase difference between a reference signal (6) and a control signal, the reference signal (6) is sampled at fixed sampling time points (S1-S7), whereby the gaps between the sampling time points (S1-S7) are variable. An output signal (PD0-PD6), which can only assume a certain number of possible states, is generated in dependence on the samplings (A0-A6) obtained at the sampling time points (S1-S7). In the case of binary sampling of the reference signal (6), the samplings (A0-A6) are present as a binary word, which can be illustrated by means of suitable logic on output signals (PD0-PD6), which again represent the various states of the output signal. Preferably, each state is depicted by the active state of an output line (PD0-PD6). In another advantageous refinement, the samplings (A0-A6) are checked for plausibility, so that in the case of an error, for example if an edge change is missing in the reference signal (6) or in the case of several edge changes of the reference signal (6), an error signal is generated and/or activation of an output line (PD0-PD6) is suppressed. For the suppression of noise buffers (3) can be provided, which only receive intermediate signals (UP0, UP1, DN0, DN1) at the last sampling time point (S5). In addition a release block can be provided, which only releases the output signal or the signals of the output lines (PD0-PD6) at the last sampling time point (S7), in order to suppress generation of an incorrect state for the output signal during the samplings (A0-A6) succeeding one another in time.

Dependencies are inferred from the claim text.