Hitachi, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Hitachi Microcomputer System, Ltd.

Toshihiko Watanabe

Hideaki Sato

Yoshimi Iso

Yuichi Ohkubo

Nobuaki Yoneya

Akihiko Rokusaka

Satoru Sekiguchi

Kazuya Hara

An apparatus for reproducing recorded information reads information from the track surface of a CD-ROM disk 1, performs error detection and correction processing on the read information to reproduce recorded information and then outputs the reproduced information. This apparatus includes a control device 11, which switches a reproduction operation to the standard speed mode in response to a correction failure condition generated in the quadruple speed mode and retries standard-speed reading of the information read with an error uncorrectable in the quadruple speed mode. Reducing the signal read speed to one-fourth in the retry processing at the standard speed improves the C/N ratio of the high-frequency signal RF by 6 dB, which in turn improves the correction capability for random errors.

Apparatus for reproducing recorded information with error detection and

A monolithic semiconductor integrated circuit device includes a differentially operative circuit section, an amplifying element connected to define a current flowing in the differentially operative circuit section and a circuit for adjusting a current flowing in the amplifying element to thereby compensate for variations of electric characteristics from one semiconductor device to another. The current adjusting circuit includes at least one amplifying element and a load resistance for the amplifying element in the current adjusting circuit. The load resistance has a structure suitable for a trimming operation to adjustably determine the resistance value of the load resistance. The amplifying elements are in a current mirror circuit connection with their control electrodes being concerned with each other so that the electric current flowing in the current path between the current receiving and delivering electrodes of the amplifying element connected to define the current flowing in the differentially operative circuit section is controlled by the adjustably determined resistance of the load resistance.

Monolithic semiconductor integrated circuit device having current

Growing community of inventors

Takasaki, Japan

Toshihiko Watanabe