Spindle Motor
The spindle motor has a “kick” mode and a run mode. The kick mode is used to start and stop the motor, bringing the motor up to speed or to a stop quickly. The CLV PB mode utilizes the pits on the disc surface to regulate the spindle motor speed.
Kick Mode
IC202 issues the kick command to start or stop the spindle motor. After- wards, all of the ICs in the Spindle Motor diagram are used in the kick mode except for IC001.
IC202
In the start program, System Control IC202 kicks (starts) the spindle mo- tor after focus is found (or after the optical assembly sleds to home posi- tion without a disc). This kick command is written to IC601 using:
·Chip select CS4 from IC202/pin 7 (low going)
·Clock from IC202/pin 5
·Write from IC202/pin 24 (low going)
·Address and Data on the parallel bus
IC601
Gate Array IC601 transfers this kick command to ARP2 IC303 using simi- lar communications:
·Chip select CS4 from IC601/pin 111 (low going)
·Common bit clock from PLL IC001/pin 1
·Write from IC601/pin 109 (low going)
·Address and Data on the parallel bus
IC303
ARP2 IC303 produces pulses at pins 49 and 52 to control the spindle motor. These motor drive speed (MDSO) and motor drive phase (MDPO) outputs are tri state voltages, combined by R820 and R822 to current drive IC802.
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Tri State Voltages from IC303/pins 49 or/and 52
Output | Spindle motor Direction |
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Open Circuit (1.6V external bias) | No rotation |
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3.3V (pulse) | Forward |
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0V (pulse) | Slows down |
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During start, both outputs at IC303/pins 49 and 52 are at 3.3V to bring the motor up to approximate data speed.
IC802
Spindle motor Driver IC802 takes the combined speed and phase volt- ages input pin 26 and amplifies them. The differential DC voltage output from IC802/pins 15 and 16 are applied to the spindle motor for rotation. The higher the voltage, the faster the spindle motor rotates.
Spindle Motor Voltage
| CD | DVD |
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Start/Stop (kick) | 5V (approx.) | 6.3V (approx.) |
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Disc Inside PB | 1.6V | 2.8V |
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Disc Outside PB | 0.98 | 1.5V |
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IC803
FG amplifier IC803 outputs a signal during a sudden spindle motor speed change. This start/stop conformation signal is returned to IC202 via IC701 and IC601 as a completion of the issued command.
IC701 and IC601
The comparators in Servo IC701 use the voltage change at pin 65 to determine when the spindle motor has started or stopped. This is be- cause IC303 in the kick chain is multi tasking and will be busy at start up. IC701’s kick confirmation signal is sent to IC601, which transfers it to System Control IC202. IC202 issues a kick stop signal after a fixed time. The kick time duration depends upon the disc type detected. A DVD is spun faster and consequently is kicked longer. After the kick mode, a new command is issued to start the spindle motor servo in the run mode.
