TDA8205

NICAM QPSK DEMODULATOR

October 1993

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GND

XC1

XC2

DF2

DF1

AGC

LFIL1

RG

GND

RFIL1

RESET

SERI

DACDL

DACDR

GND

CK11648

CK728

NDO

TEST

MMO

GND

AOL

AOR

DC1

DC2

AMOL

AMOR

CAP

MAI

SAIL

SAIR

EAIL

EAIR

XK1

LF1

LF2

V

CC

IN

I

V

DD

BG

IN

CC

V

DD

V

PIN CONNECTIONS

SHRINK 42

(Plastic Package)

ORDER CODE : TDA8205

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HIGHLY INTEGRATED TWO CHIP SOLU-

TION FOR NICAM DEMODULATION (using

TDA8204 decoder)

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AUTOMATIC DUAL STANDARD DEMODULA-

TION

6.552MHz FOR I SYSTEM

5.85MHz FOR B/G SYSTEM

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40dB RANGE AGC

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SINGLE CRYSTAL OPERATION

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NICAM 728 DATA AND CLOCK RECOVERY

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LOW PASS FILTER FOR PWM CODED

AUDIO SIGNALS AND J-17 DE-EMPHASIS

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AUTOMATIC FM MONO SELECTION BY RE-

SERVE SOUND SWITCH FUNCTION

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VERSATILE AUDIO SWITCHING MATRIX

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AUTOMATIC MUTE FUNCTION

DESCRIPTION

The TDA8205 is essentially divided into two signal

processing sections. The first section handles all

the NICAM signal acquisition, the QPSK demodu-

lator and clock and data recovery circuits. The key

point to note about this section is the dual fre-

quency synthesiser. By use of only one quartz

crystal, the IC is able to demodulate QPSK signals

from either system I or system B/G in an automatic

way. The second section of the TDA8205 manages

the analog parts of the twin digital-to-analog con-

verters (DACs) and all filtering and audio switching

downstream of the DACs. A simple serial bus from

the TDA8204 allows control of the switch functions

by the CTV system microcontroller.

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