16

1

WIDE BAND AMPLIFIER

DEMODULATOR

VIDEO

IW

11

10

9

8

7

SUPPLY

UNIT

GATING

AMPLIFIER

13

45

6

VIDEO

OUTPUT

GATING

PULSE

IF INPUT

IF INPUT

TUNER

AGC

OUTPUT

TUNER

AGC

ADJUST

V

CC

2

STANDARD

SWITCH

3

15

V

S

CONTROL

AMPLIFIER

TUNER

CONTROL

TDA4443

BLOCK DIAGRAM

GENERAL DESCRIPTION

This video IF processing circuit integrates the fol-

lowing functional blocks :

.

Three symmetrical, very stable, gain controlled

wideband amplifier stages - without feedback

by a quasi-galvanic coupling.

.

Demodulator controlled by the picture carrier

.

Video output amplifier with high supply voltage

rejection

.

Polarity switch for the video output signal

.

AGC on peak white level

.

Gated AGC

.

Discharge control

.

Delayed tuner AGC

.

At VTR Reading mode the video output signal

is at ultra white level

TDA4443

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