SGS Thomson Microelectronics TDA8222 Datasheet

WITH VIDEO AN D SO UN D SWITC H ES

.

3 ST A G E IF GAI N CO NT RO LL E D AM PLI F IER

.

SYNCHRONOUS VIDEO DEMODULATOR

.

TOP SYNC A G C CI RCUIT

.

WHIT E A N D B LACK NOIS E INVERTER

.

TUNER AGC OUTPUT FOR PNP TUNERS
(suitable also for MOSF ET tuners)

.

ANALOG AFC

.

FM DETECTOR

.

AUDIO AND VIDEO SWITCHES COMPAT­IBLE WITH SCART EUROPEAN NORM

.

DC VOLUME CO NTRO L

.

MUTE FUNCTION

TDA8222

VIDEO & SOUND IF SYSTEM

SHRINK DIP24

(Plastic Package)

DESCRIP TION

The TDA8222 is a video and sound IF circuit in
Shrink DIP24 pack age for color and black and white
TV sets. It is intended to operate with a negatively
modulated vision carrier and frequency modulated
sound carrier. It incorporates video and audio
switches compatible with SCA RT european norm.

PIN CONNECTIONS

TUNER AGC STARTING POINT ADJUSTMENT

TUNER AGC OUTPUT

V

CC

VIDEO SWITCH
BALANCED IF INPUT
BALANCED IF INPUT

AUDIO SWITCH OUTPUT

VOLUME CONTROL

V

CC

GROUND

1
2
3
4
5
6
7
8
9

ORDER CODE : TDA8222

24
23
22
21
20
19
18
17
16

AGC TIME CONSTANT
IF LC
IF LC
SWITCHING INPUT
AFC LC
AFC OUTPUT
DEMODULATED CVBS OUTPUT
EXTERNAL AUDIO INPUT
2nd IF SOUND INPUT

October 1993

FM REFERENCE TUNED CIRCUIT

DEMODULATED AUDIO OUTPUT

VIDEO SWITCH OUTPUT

10
11
12

15
14
13

2nd IF DECOUPLING INPUT + MUTE
INTERNAL VIDEO INPUT
EXTERNAL VIDEO INPUT

8222-01.EPS

1/9

TDA8222

BLOCK DIAG RAM

3

12423

22

20

17

11

2

5
6

9

8

Tuner

AGC

IF Amplifier

Band Gap

Voltage Re feren ce

D.C. Volume

Control

FM

Discri

Limiter

LP Filter

Reference

Amplifier

Mute

AFCAGC

Video

Ampli fier

White and

Black Noise Inverter

6dB

6dB

19

18

4

14

12

13

TDA8222

151610

21

7

8222-02.EPS

FUNCTIONAL DESCRIPTION
General

The IC consists of the following parts (see block
diagram):

- Three stages gain controlled wide band amplifier

- Quasi-synchronous demodulator

- Video amplifier with white and black noise in­verter

- AGC circuit which operates on top sync level

- Analog AFC circuit

- FM discriminator

- Mute function

- Video and audio switches

- DC volume control

IF Amp lifier

It consists of three cascaded AC coupled differen­tial gain stages. The gain of each amplifier is con­trolled by the AGC volt age. The global AG C range
is more than 60dB. Thanks to the internal AC
coupling no DC feedback is required.

Demo du lation

It is a quasi-synchronous type with passive carrier

regeneration done by an ext ernal tuned circuit, a nd
a limiter amplifier.

Video A mp lifier

The video amplifier provides a 2V

video signal to

PP

the output with a good phase and amplitude fre­quency response.

White and Black Noise Inverter

A fixed 3.2V level is inserted when a white spot
above 4.5V (measured on the video output Pin 18)
happens, this prevents from very noisy signal on
the screen.

A fixed 2.5V level is inserted when a black spot
below 1.3V happens, this to avoid sync hronization
on parasitic signals.

AGC Circuit

The AGC detector operates on top sync level, an
external capacitor o n Pin 24 controls t he tim e co n­stant.

The voltage on this capacitor is converted into a
current to control the amplifier stage.

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TDA8222

T u ner AG C

It sinks a current to cont rol the gain of the tuner RF
amplifier . Its star ting point is adjusted by an external
potentiometer (Pin 1).

AFC Circui t

It is a FM demodulator stage which delivers on
Pin 19 a current proportional to the frequency dif­ference between the IF input signal and the refer­ence IF frequency of the external LC on Pin 20. This
current is converted into a voltage by means of a
resistor network.

FM Demodulation

It consists of a three stage limiter amplifier in order
to reject the amplitude modulation and a quadra­ture demodulator. The deemphasis filter is built
with an internal resistor and an external capacitor
on Pin 1 1.

Mute Function

It is an internal switch to cut-off the internal audio
signal. It acts when a level below 2.1V is applied
on Pin 15. When no mute, the Pin 15 must be driven
with a high DC impedance.

Video and Audio Switches

They are both controlled by the Pin 21 voltage.
Internal sources or ex tern al sources can be sent to

the outputs (Pin 12 for video and Pin 8 for audio).
The internal signals are select ed by a control l ev el
below 2.5V on Pin 21, the external o nes by a control
level above 5V.

The gain of the video switch is 6dB for both internal
and external signals.

The gain of the audio switch is 0dB for the maxi­mum volume.

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

S

V

X

T

stg

T

oper

Supply Voltage 13.5 V
Tuner AGC V ol tage V
Storage Temperature -40, +150
Operating Temperature 0, +70

CC

V

o

C

o

C

8222-01.TBL

THERMAL DATA

Symbol Parameter Value Unit

R

th (j-a)

Junction-ambient Thermal Resistance Max. 75

ELECTRICAL CHARACTERISTICS

(T

= 25oC, VCC = 9V, IF input = 10mV

amb

Sound carrier input : 5.5MHz, 10mV
V olume attenuation = 0dB, R

Symbol Parameter Test Conditions Min. Typ. Max. Unit

SUPPLY

V

CC

I

CC

IF AMPLIFIER

R

22-23

C

22-23

G

R

DEMODULATED VIDEO OUTPUT (Pin 18)

V

A18

V

S18

BW Bandwidth See Figure 1 5 7 MHz

Voltage Operating Range 8.1 9 12.6 V
Supply Current I(3) + I(4), VCC = 9V 24 38 52 mA

Input Sensitivity Refer to test circuit 70 µV
Differential Input Resistance 1.5 kΩ
Differential Input Capacitance 2 pF
Gain Control Range 64 dB

Amplitude Top sync to white 1.8 2.1 2.4 V
Top Sync Level without output filter 1.6 1.9 2.2 V

load

RMS

on Pin 12 = 1kΩ, unless otherwise specified)

top sync, D = 90%, Video BW = 5MHz,

RMS

, fm = 1kHz, Audio BW = 20k Hz, ∆f = ± 25kHz,

o

C/W

8222-02.TBL

PP

8222-03.TBL

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