DATA DEMODULATOR

PURPOSE:To attain equalization operation even when a phase of a recovered data clock reaches the vicinity of a worst point of an eye pattern. CONSTITUTION:A demodulator 2 demodulates a data signal whose period is T into a base band signal whose period is T/2 and gives the demodulated signal to an automatic equalizer 31. The automatic equalizer 31 equalizes the demodulated signal and outputs the equalized signal to an error correction circuit 33. When the error correction circuit 33 generates an error detection signal representing error correction disable, an initializing circuit 32 initializes the setting to shift a main tap position by one tap. Thus, the phase of the clock is generated in the vicinity of a best point of an eye pattern equivalently and the excellent equalization is realized.