Overview

The LC78626KE is a monolithic compact disk player signal processing and servo control CMOS IC equipped with an internal anti-shock control function. Designed for total functionality including support for EFM-PLL, and one-bit D/A converter, and containing analog low-pass filter, the LC78626KE provides optimal cost-performance for low-end CD players that provide anti-shock systems by eliminating as many unnecessary features as possible.

Functions

• When an HF signal is input, it is sliced to precise levels and converted to an EFM signal. The phase is compared with the internal VCO and a PLL clock is reproduced at an average frequency of 4.3218 MHz.

• Precise timing for a variety of required internal timing needs (including the generation of the reference clock) is produced by the attachment of an external 16.9344 MHz crystal oscillator.

• The speed of revolution of the disk motor is controlled by the frame phase difference signal generated by the playback clock and the reference clock.

• The frame synchronizing signal is detected, stored, and interpolated to insure stable data read back.

• The EFM signal is demodulated and converted to 8-bit symbolic data.

• The demodulated EFM signal is divided into subcodes and output to the external microprocessor. (Three general I/O ports are shared [exclusively] for this purpose.)

• After the subcode Q signal passes the CRC check, it is output to the microprocessor through a serial transmission (LSB first).

• The demodulated EFM signal is buffered in the internal RAM, which is able to absorb ±4 frame’s worth of jitter resulting from variations in the disk rotation speed.

• The demodulated EFM signal is unscrambled to a specific sequence, and deinterleaving is performed.