S5L9250B Datasheet, PDF(63/163 Page) Samsung semiconductor – The CD-ROM 48X 1 chip receives the input signal read from the CD-DA/VIDEO-CD/CD-ROM disc after handling by the RF amplifier.

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S5L9250B Datasheet, PDF (63/163 Pages) Samsung semiconductor – The CD-ROM 48X 1 chip receives the input signal read from the CD-DA/VIDEO-CD/CD-ROM disc after handling by the RF amplifier.

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DATA SHEET

S5L9250B

FOCUS BIAS

Summary

The purpose of adjusting the Focus Bias is to insure optimum RF signal quality during PLAY. Although it is the

Jitter amount that shows RF signal quality, it is very difficult to actually measure the jitter on the IC and create an

algorithm to find the point of minimum jitter. The alternative is to adjust the Focus Bias so that the envelope size

is at its maximum. The RF signal has the characteristic of having the least jitter near the point of Focus Bias

when the RF envelope size is at its maximum.

ï£§ Input signal : FE, RFENV

ï£§ Output signal : FOD

Command

FBAcmd (0x11 00)

: When the RF signal is at its maximum, end Focus Balance Adjust using the RF Envelope signal.

Always use after Focus pull-in.

Code

1'st byte

TFBA

TFBA : Test mode for FBA.

0 : Normal FBA.

1 : Execute Focus Balance once then revert to previous mode, without regard to Focus Balance OK.

Related Memory

Name

tFBacc

FBdx

FBlevel

FBok

FBIAS

Address

00D0

00D1

00D2

00D3

0097

Function

Disturbance Width

BIAS increase/decrease amount Buffer

Disturbance Level

Bias OK Level

fbias data save

Data

05EA

0080

1000

0100

Value

8.58ms

9.8mV

312.5mV

19.5mV

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