FREQUENCY DETECTION CIRCUIT, PHASE/FREQUENCY DETECTOR CIRCUIT, AND FREQUENCY DETECTION METHOD

摘要

To provide an accurate frequency acquisition circuit and a frequency detection method.SOLUTION: A frequency detection circuit according to one embodiment of the present invention comprises: a transition detector configured to receive a data input and provide a first edge output based on transitions in the data input; a first circuit configured to generate a second edge output; a second circuit configured to generate a third edge output; and a combinational logic. The combinational logic circuit according to the one embodiment of the present invention is configured to: output an UP output when at least two of the first edge output, the second edge output, and the third edge output have a high value; and output a DOWN output when the first edge output, the second edge output, and the third edge output all have a low value.SELECTED DRAWING: Figure 3