Abstract: An apparatus for use in a digital recording/reproducing system includes a first comparator for receiving a reproduced analog signal, comparing the voltage level thereof with a first reference voltage of a predetermined level, and outputting a first comparison result; a switch for switching on and off a connection with the reproduced analog signal in accordance with the first comparison result; a reference voltage adjuster for charging or discharging a charge element in accordance with the on/off state of the switch in the switch, and adjusting a second reference voltage of a predetermined level for data detection; a second comparator for receiving a reproduced analog signal, comparing the voltage level thereof with the second reference voltage adjusted in the reference voltage adjuster, and outputting a second comparison result; and a restorer for receiving the second comparison result, synchronizing the received result with a clock signal, and restoring the synchronized signal into a digital signal.

Abstract: An optimum recording/reproducing apparatus for optimally performing recording and reproduction according to the change of data recording and reproducing environments, to record digital data on a predetermined recording medium by using a recording head and reproducing the recorded data by using the reproducing head to be output, includes a recording apparatus comprising a memory, a modulator, an envelope detector and a clock generator, whereby the rate of reading out the data from the memory and the modulating clock signal applied to the modulator are determined according to the clock signal; and a reproducing apparatus comprising a detector, a phase-locked loop (PLL) circuit, a demodulator and a memory.