LC7868KE データシートの表示（PDF） - SANYO -> Panasonic

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LC7868KE

Digital Signal Processor for Compact Disc Players

SANYO -> Panasonic 

LC7868KE

7. CLV servo circuit; Pin 10: CLV+, pin 11: CLV–, pin 12: V/P

MSB

LSB

00000100

00000101

00000110

00000111

Command

DISC MOTOR START (accelerate)

DISC MOTOR CLV (CLV)

DISC MOTOR BRAKE (decelerate)

DISC MOTOR STOP (stop)

RES = low

○

The CLV+ pin provides the signal that accelerates the disk in the forward direction and the CLV– pin provides the

signal that decelerates the disk. Commands from the control microprocessor select one of four modes; accelerate,

decelerate, CLV and stop. The table below lists the CLV+ and CLV– outputs in each of these modes.

Mode

Accelerate

Decelerate

CLV

Stop

CLV+

High

Low

*

Low

CLV–

Low

High

*

Low

Note: CLV servo control commands can set the TOFF pin low only in CLV mode. That pin will be at the high level

at all other times.

• CLV mode

In CLV mode the LC7868KE detects the disk speed from the HF signal and provides proper linear speed using

several different control schemes by switching the DSP internal modes. The PWM period is 7.35 kHz, the 1/64

duty period is 1.114s, and V/P outputs a high level during rough servo and a low level during phase control.

Internal mode

Rough servo (velocity too low)

Rough servo (velocity too high)

Phase control (PCK locked)

CLV+

High

Low

PWM

CLV–

Low

High

PWM

V/P

High

High

Low

No. 4882-10/24

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