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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