Patent ID: 8223603
Filing Date: 2012-07-17
Classification: G11B

Abstract:
1. A frequency detection apparatus, comprising: a signal boost filter configured to filter out and boost a high frequency component of an input signal; a frequency detector configured to detect a frequency difference between the input signal having the boosted high frequency component and a clock signal and produce a control voltage corresponding to the frequency difference, wherein the signal boost filter comprises: a nonlinear converter configured to control the input signal using a predetermined range, the nonlinear converter being configured to output one of a controlled signal if a magnitude of the input signal is greater or less than the predetermined range and a signal of 0 if the magnitude of the input signal is within the predetermined range; a plurality of filters configured to filter out and boost a high frequency component of the controlled signal and the high frequency component of the input signal; and an adder configured to add the input signal having the boosted high frequency component to the controlled signal having the boosted high frequency component.