Sony DVP S530D User Manual download pdf (Page 68)

PM3394, FLUKE & PHILIPS

ch4

ch3

ch2

ch1

CH1!2.00 V=

CH2!2.00 V=

CH3! 200mV~

CH4!2.00 V= CHP MTB50.0us ch1+

CLV PB Mode

In the CLV PB mode, IC001, IC303 and IC802 are used to regulate the

spindle motor speed. System Control IC202 issues a CLV run command

to IC303. By this time, the disc has reached data output speed so IC303

can use the data to govern the spindle motor. RF output from IC001/pin

54 is processed by IC303. IC303 compares the RF input to internal CD or

DVD references and produces MDS and MDP spindle motor correction

pulses. The correction pulses vary the speed of the motor so the RF disc

data is always output at a constant rate. This is called constant linear

velocity.

The following waveform taken during DVD playback shows that the MDP

(ch 2) signals are periodic pulses that keep the disc spinning forward.

The MDS (ch 1) pulses provide incremental speed correction in the form

of 3V or 0 V pulses to speed up or slow down the motor. The combined

MDP + MDS voltage at IC802/pin 26 is shown in channel 3. The feed-

back signal (ch 4) is only present during a drastic spindle motor speed

change, so it remains at 3V during DVD playback.

Motor Drive Signals

Name Location Voltage/div.

Channel 1 MDS IC303/pin 49 2Vp-p

Channel 2 MDP IC303/pin 52 2Vp-p

Channel 3 Composite

drive

IC802/pin 26 0.2Vp-p (AC coupled)

Channel 4 Feedback IC701/pin 65 2Vp-p

Time base 50usec/div.

1 2 ... 63 64 65 66 67 68 69 70 71 72 73 ... 91 92

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Sony DVP S530D User Manual Page 68