YDC103

The YDC103 is one-chip CMOS LSI to provide various servo control and signal processing needed for the CD player.By built-in digital PLL clock regeneration circuit and 16k RAM, it performs EFM signal demodulation, error detection and correction, and fitter absorption.It also performs various intelligent servo controls for focussing, tracking, feeding and disc motor.In addition, as this LSI has sigma-delta type 1-bit DACs, even analog audio signals are obtained easily with only some external parts attached.Furthermore, it is provided with a digital audio interface output function which conforms to the EIAJ format.

Features of the YDC103 are:(1)generates standard clock and necessary timing singals with a crystal connected; (2)with the digital pll and slice level control circuit built in, it performs efm signal clock regeneration, synchronous signal separation and efm demodulation; (3)crc-checks the q sub-code and outputs to the microprocessor in addition to separating the sub-code and providing the output conforming to the eiaj format; (4)detects the phase difference between the regenerated and standard clock signals and controls the disc motor by means of pwm; (5)easy servo control by focussing search, track auto search and track count functions; (6)linear interpolation processing is used for up to 8 consecutive uncorrectable error data and preceeding data hold processing for errors over eight; (7)the de-emphasis processing function, 8-times digial filter and 3rd order sigma-delta system 1-bit dacs are built in so that analog signals can be obtained easily; (8)outputs digital audio interface signals conforming to EIAJ format.

The absolute maximum ratings of the YDC103 can be summarized as:(1)power supply voltage Vdd:-0.3-7.0V; (2)input voltage Vi:-0.3-Vdd+0.5V; (3)operating temperature Top:-20~75; (4)storage temperature Tstg:-50~125.For power reinforcement, power supply pins are provided for the 1-bit DAC section. LVDD and LVSS pins are for the L channel and RVDD and RVSS pins are for the R channel. Due to the structural reason of the LSI, however, the same power supply should be used. The DAC does not operate in EXDAC and CD-ROM modes.Note that when in the DSP mode, digital attenuation processing is performed on the SDI input and is not reflected on the SDO output. When in any other mode, this terminal is not used and therefore the SDI terminal should be connected with VSS.