Patent ID: 8085639

Claim:
An information reproducing apparatus comprising: an A/D converter that samples an analog signal in synchrony with a system clock having a fixed frequency, to convert the analog signal into a digital signal, said analog signal including therein a channel clock having a variable channel frequency; an internal-feedback-type fluctuation compensator that suppresses fluctuation of the digital signal output from said A/D converter; a digital PLL that generates, from the digital signal output from said fluctuation compensator, a plurality of interpolated sampled values of the analog signal at respective timings in synchrony with the channel clock, and generates a synchronizing clock having the variable channel frequency based on the interpolated sampled values; and a demodulator that identifies the digital information based on the interpolated sampled values and the synchronizing clock, wherein said fluctuation compensator has a frequency characteristic that is controlled depending on the frequency of the synchronizing clock; and said fluctuation compensator comprises an AGC (auto gain controller) that can control a loop characteristic based on the frequency of the synchronizing clock.