To provide an equalizer and method for the same which enable a chip size to be reduced by decreasing distortion in a filtered signal and determining values of filtering coefficients even without using a comparator.

The equalizer is characterized in including a filtering circuit, a filter control circuit and a coefficient updating circuit. The filtering circuit filters an input data signal based on a plurality of filtering coefficients and outputs an output data signal. Each of a plurality of filter cells includes a coefficient buffer that is enabled or disabled in response to one of filtering control signals and stores one of filtering coefficients when enabled. The filter control circuit determines values of the filtering coefficients in response to a bit selection signal and outputs a filtering control signal based on the determination result. The coefficient updating circuit generates the filtering coefficients, estimates a channel in response to the input data signal and updates the values of the filtering coefficients in accordance with the estimation results. Thus, the distortion and chip size of the filtered signal can be decreased.