3 , feed servo circuit :

CXD3068 (29), (30) pin output PWM control signal , sent BA6392 (4 ) , ( 5 ) feet, the feed servo control voltage from the driver amplifier (1 ) , ( 2 ) pin outputs, plus to feed both ends of the motor , the motor driven feed laser head assembly for CD track scan.

4 , the spindle servo circuit :

During playback , the laser head after reading the signals amplified by CXA2550 from ( 15 ) pin output to CXD3068 (50) feet, after pre-processing to the digital PLL circuit , first isolated from the edge detection circuit from the EFM signal discontinuous pulse signal is then supplied to a phase comparator in the PLL circuit , a VCO control circuit in the PLL circuit generates a signal synchronized with the EFM , and continuous pulse , the spindle motor control to the CLV processor circuit , and comparing the reference clock signal , the error signal CLV processor speed spindle servo control voltage to adjust the spindle motor drive current CXD3068 section ( 25 ) output is fed BA6392, to achieve the purpose of CLV servo .

5 , the frequency compensation circuit :

Because when you read VCD and Super VCD discs, movement speed were working in single or double -speed state , RF amplification circuit before mixing , this frequency compensation circuit parameters required two RF signal is adjusted so that the waveform were reached the best results. Q4, C164, C165 control frequency compensation circuit composed by CL8830A (17) feet to control the working status of the output voltage of Q4 , changing compensation capacitor capacity to implement this feature.

6, CPU interface circuit

CXD3068 chip embedded CPU interface consists of 4 feet (DATA), 5 feet (XLAT), 6 feet (CLOCK) tripod structure, they receive instructions from the CPU 3883 emitted from within to deal with associated circuitry. Control the focus, tracking , radial , gain, error correction and other parts , and by 7 feet (SENS), 76 feet (SQSO), 22 feet (FOK), 15 feet (SCOR) transmit a variety of work to the CPU process state and allow the circumstances to understand 3883 , issue the proper command to 7 feet (SENS) of the chip is the most important condition to the CPU notices lines in different operating state , the transmission state of the corresponding parameter .

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