Hitachi, Ltd.

Satoshi Minoshima

Terumi Takashi

Hideki Miyasaka

Seiichi Mita

Naoki Satoh

Yoshiju Watanabe

Shoichi Miyazawa

Yasuhide Ouchi

Akihiko Hirano

Ryushi Shimokawa

Yosuke Hori

Toshihiro Nitta

Koji Shida

Tomoaki Hirai

Naoto Matsunami

Hiromi Matsushige

Kazunori Iwabuchi

Tsuguji Tachiuchi

Minoru Kosuge

Yasuhiro Shimura

A signal processing circuit for a magnetic recording/reproducing apparatus, including at least an AGC, a PLL, a LPF, an equalizer circuit and a detection circuit, wherein a coefficient compensation circuit is formed by defining a constitution of the equalizer circuit, an error detection circuit is provided which operates by receiving input from the detection circuit, and the LSI is formed by a plurality of analog and digital chips, and the analog and digital chips are connected by current-output type D/A converters connected to at least the AGC and the PLL.

Signal processing circuit and information recording/reproducing apparatus using the same, and method for optimizing coefficients of equalizer circuit

Signal processing circuit and information recording/reproducing

A data reproducing circuit having a magnetic head for reading data from a recording medium, an adaptive equalization circuit for optimizing the waveform of a read signal, a discriminator circuit for discriminating an output signal of the adaptive equalization circuit and outputting a discriminated signal to an upper stage circuit, a format detecting circuit for detecting a pattern of signals written on the recording medium from outputs of the magnetic head, an expected value generating circuit for generating an expected value of the waveform of the read signal in accordance with an output of the adaptive equalization circuit and an output of the discriminator circuit, and an error detecting circuit for generating an error signal representing a difference between an output of the adaptive equalization circuit and an output of the expected value generating circuit. In the data reproducing circuit, the adaptive equalization characteristic of the adaptive equalization circuit is changed when a particular signal pattern on the recording medium is detected, allowing the adaptive equalization operation suitable for the recording medium.

Adaptive equalization circuit for magnetic recording apparatus having

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Fujisawa, Japan

Satoshi Minoshima