YM7121C

The YM7121C is one-chip CMOS LSI to provide various servo control and signal processing capacibilities needed in compact disc players.There are some features of YM7121C as follows.First, the built-in VCO oscillation and slice level control circuit perform clock reproduction,sync. signal seperation and EFM demodulation.Secondly, in addition to sub code seperation and output following to EIAJ format, Q sub codes are CRC checked for output to a microprocessor.Besides, phase difference between reproduced and standard clock signals is detected to control the disc motor with PWM.Furthermore, command input on a microprocessor administrates various servo controls for focusing search as well as tracking feed for quick access and skipping.The fifth one is that EFM demodulation signals are unscrambled and de-interleaved.The sixth is error detection and correction as well as flag processing for digital audio signals (Double error correction for both C1 and C2).

What comes next is about the absolute maximum ratings of YM7121C.The VDD (power supply voltage) is from -0.3 V to +7.0 V.The VI (input voltage) is from -0.3 V to VDD+0.5 V.The Pd (power dissipation) is 150 mW.The Iin (input current) is 10 mA.The Top (operating temperature) is from -20 to +75.The Tstg (storage temperature) is from -50 to +125.Then is about the recommended operating conditions.The minimum VDD (power supply voltage) is 4.75 V,the typicall is 5.00 V and the maximum is 5.25 V.The minimum Top (operating temperature) is 0,the typical is 25 and the maximum is 70.

The following is about the DC characteristics of YM7121C.The maximum IDD (power supply current) is 70 mA at VDD=5 V.The minimum VOH (high level output voltage) is 4.0 V at IOH=20A.The maximum VOL (low level output voltage) is 0.4 V at IOL=1 mA.The maximum VIL1 (low level input voltage) is 1.5 V and the minimum VIH1 (high level input voltage) is 3.5 V applicable to the terminals EFMI, FZC, FRF, HF, TER, RCK.The maximum VIL2 (low level input voltage) is 0.8 V and the minimum VIH2 (high level input voltage) is 2.0 V applicable to the terminals DIN, SCK.