S5L1454A 查看數據表（PDF） - Samsung

零件编号

产品描述 (功能)

生产厂家

S5L1454A

DVD PLAYER DIGITAL SERVO & DSP IC

Samsung 

DVD PLAYER DIGITAL SERVO & DSP IC

S5L1454A

¢º¢º FOCUS BIAS CONTROL

Summary

Focus bias adjustment is carried out so that playback is executed when the RF signal quality is at its best. The

quality of the RF signal is shown by the jitter amount, but it is difficult to have an algorithm that can measure jitter

on the IC and find the minimum point. Therefore, you use the characteristic where the jitter is always at its

minimum near the focus bias point with the largest RF envelope size. The focus bias is adjusted so that the

envelope is at its maximum size.

Rf env

Max

 Input signal: FE, RFENV

 Output signal: FOD

Jitter

min

Focus Bias

FinG

FE

(from RF) pin

x(-N)

fs

FE

+

+

FEin FOCUS LOOP

FILTER

FOD

+

pin

Fofst Fbias

RFENV

pin

(from RF)

fs/16

RFENV Avrg RF_ENV FOCUS BIAS ERR DISTURBANCE

FILTER

Processor

GENERATOR

COMMAND

FBAcmd(B2xxxx)

Related Register

REGISTER

FBpd

FBok

dXbuf

ADDR.

0059

10B0

002F

FUNCTION

Focus Bias control RFENV measurment cycle

Focus Bias ok level

Initial dX setting level

COMMAND

AAFFF4

ADFFF0

AEFFFB

Operation Description

RFENV's signal difference is minimized by the FE signal carrying the disturbance. The disturbance uses the FE

as reference and is used after selecting +, - dX. The disturbance level value is given to the first + direction, the

RFenv value is stored, and + drepeated so that the dxbuf amount of the largest RFENV level is added/subtracted

from the Fbias amount to find the final Fbias.

29

Share Link: