A data recovery apparatus for minimizing errors due to clock skew and a data
recovery
apparatus therefor are provided. The data recovery apparatus comprises a phase
locked loop (PLL), an oversampler, a level transition detector, a transition accumulator,
a state selector, and a data selector. The PLL generates a plurality of phase clock
signals having different delay times, which signals are synchronized with an input
clock signal. The oversampler 110 M (1) times oversamples data serially
input from the outside in response to the plurality of phase clock signals and
outputs the oversampled result as a plurality of bit data items. The level transition
detector receives the plurality of bit data output from the oversampler, detects
the point of time at which the level transitions between adjacent bits and outputs
the detection result as first through Mth transition signals. The transition accumulator
accumulates the number of generations of the first through Mth transition signals
output from the level transition detector and outputs a signal whose generation
frequency is high as first through Mth transition accumulation signals. The state
selector generates a state signal for selecting bit data items of corresponding
positions among the plurality oversampling data items in response to the first
through Mth transition accumulation signal. The data selector receives the oversampled
plurality of bit data, selects bit data items of the sampling positions corresponding
to the state signal, and outputs the selected bit data items in parallel. It is
possible to minimize errors due to clock skew, which can be generated during the
reproduction of data.