TDA8222.PDF

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VIDEO & SOUND IF SYSTEM WITH VIDEO AND SOUND SWITCHES
TDA8222
VIDEO & SOUND IF SYSTEM
WITH VIDEO AND SOUND SWITCHES
. 3 STAGE IF GAIN CONTROLLED AMPLIFIER
. SYNCHRONOUS VIDEO DEMODULATOR
. TUNER AGC OUTPUT FOR PNP TUNERS
(suitable also for MOSFET tuners)
. ANALOG AFC
. AUDIO AND VIDEO SWITCHES COMPAT-
IBLE WITH SCART EUROPEAN NORM
. DC VOLUME CONTROL
. MUTE FUNCTION
SHRINK DIP24
(Plastic Package)
DESCRIPTION
The TDA8222 is a video and sound IF circuit in
Shrink DIP24 package 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 SCART european norm.
ORDER CODE : TDA8222
PIN CONNECTIONS
TUNER AGC STARTING POINT ADJUSTMENT
1
24
AGC TIME CONSTANT
TUNER AGC OUTPUT
2
23
IF LC
V CC
3
22
IF LC
VIDEO SWITCH
V CC
4
21
SWITCHING INPUT
BALANCED IF INPUT
5
20
AFC LC
BALANCED IF INPUT
6
19
AFC OUTPUT
GROUND
7
18
DEMODULATED CVBS OUTPUT
AUDIO SWITCH OUTPUT
8
17
EXTERNAL AUDIO INPUT
VOLUME CONTROL
9
16
2nd IF SOUND INPUT
FM REFERENCE TUNED CIRCUIT
10
15
2nd IF DECOUPLING INPUT + MUTE
DEMODULATED AUDIO OUTPUT
11
14
INTERNAL VIDEO INPUT
VIDEO SWITCH OUTPUT
12
13
EXTERNAL VIDEO INPUT
October 1993
1/9
. TOP SYNC AGC CIRCUIT
. WHITE AND BLACK NOISE INVERTER
. FM DETECTOR
11039366.002.png
TDA8222
BLOCK DIAGRAM
3
1
24
23
22
20
2
Tuner
AGC
AGC
Reference
Amplifier
AFC
19
5
Video
Amplifier
IF Amplifier
6
Band Gap
Voltage Reference
White and
Black Noise Inverter
18
4
9
14
8
D.C. Volume
Control
6dB
17
12
6dB
11
FM
Discri
Limiter
LP Filter
Mute
13
10
16
15
21
7
TDA8222
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 in-
verter
- AGC circuit which operates on top sync level
- Analog AFC circuit
- FM discriminator
- Mute function
- Video and audio switches
- DC volume control
regeneration done by an external tuned circuit, and
a limiter amplifier.
Video Amplifier
The video amplifier provides a 2V PP video signal to
the output with a good phase and amplitude fre-
quency 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 synchronization
on parasitic signals.
AGC Circuit
The AGC detector operates on top sync level, an
external capacitor on Pin 24 controls the time con-
stant.
The voltage on this capacitor is converted into a
current to control the amplifier stage.
IF Amplifier
It consists of three cascaded AC coupled differen-
tial gain stages. The gain of each amplifier is con-
trolled by the AGC voltage. The global AGC range
is more than 60dB. Thanks to the internal AC
coupling no DC feedback is required.
Demodulation
It is a quasi-synchronous type with passive carrier
2/9
11039366.003.png
TDA8222
Tuner AGC
It sinks a current to control the gain of the tuner RF
amplifier. Its starting point is adjusted by an external
potentiometer (Pin 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.
AFC Circuit
It is a FM demodulator stage which delivers on
Pin 19 a current proportional to the frequency dif-
ference between the IF input signal and the refer-
ence IF frequency of the external LC on Pin 20. This
current is converted into a voltage by means of a
resistor network.
Video and Audio Switches
They are both controlled by the Pin 21 voltage.
Internal sources or external sources can be sent to
the outputs (Pin 12 for video and Pin 8 for audio).
The internal signals are selected by a control level
below 2.5V on Pin 21, the external ones bya 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 maxi-
mum volume.
FM Demodulation
It consists of a three stage limiter amplifier in order
to reject the amplitude modulation and a quadra-
ture demodulator. The deemphasis filter is built
with an internal resistor and an external capacitor
on Pin 11.
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V S
Supply Voltage
13.5
V
V X
Tuner AGC Voltage
V CC
V
T stg
Storage Temperature
-40, +150
o C
o C
T oper
Operating Temperature
0, +70
THERMAL DATA
Symbol
Parameter
Value
Unit
R th (j-a)
Junction-ambient Thermal Resistance
Max.
75
o C/W
ELECTRICAL CHARACTERISTICS
(T amb =25 o C, V CC = 9V, IF input = 10mV RMS top sync, D = 90%, Video BW = 5MHz,
Sound carrier input : 5.5MHz, 10mV RMS ,f m = 1kHz, Audio BW = 20kHz, D f= ± 25kHz,
Volume attenuation = 0dB, R load on Pin 12 = 1k W , unless otherwise specified)
Symbol
Parameter
Test Condition s
Min.
Typ.
Max.
Unit
SUPPLY
V CC
Voltage Operating Range
8.1
9
12.6
V
I CC
Supply Current
I(3) + I(4), V CC = 9V
24
38
52
A
IF AMPLIFIER
Input Sensitivity
Refer to test circuit
70
m
V
R 22-23
Differential Input Resistance
1.5
k
W
C 22-23
Differential Input Capacitance
2
pF
G R
Gain Control Range
64
dB
DEMODULATED VIDEO OUTPUT (Pin 18)
V A18
Amplitude
Top sync to white
1.8
2.1
2.4
V PP
V S18
Top Sync Level
without output filter
1.6
1.9
2.2
V
BW
Bandwidth
See Figure 1
5
7
MHz
3/9
11039366.004.png
TDA8222
ELECTRICAL CHARACTERISTICS (continued)
(T amb =25 o C, V CC = 9V, IF input = 10mV RMS top sync, D = 90%, Video BW = 5MHz,
Sound carrier input : 5.5MHz, 10mV RMS ,f m = 1kHz, Audio BW = 20kHz, D f= ± 25kHz,
Volume attenuation = 0dB, R load on Pin 12 = 1k W , unless otherwise specified)
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
DEMODULATED VIDEO OUTPUT (Pin 18) (continued)
D G
Differential Gain
IF input = 5mV RMS top sync
3
7
%
D P
Differential Phase
3
7
Degree
V 18
Residual Carrier Signal (RMS
value)
1
10
V
V 18
Residual 2nd Harmonic (RMS
value)
2
20
V
I 18
Internal Bias of Emitter Follower
3
5
mA
S/N
Signal to Noise Ratio
Note 1
55
dB
Intermodulation 1.07MHz
Note 2
50
dB
V WTH
White Noise Threshold Voltage
See Figure 5
4.5
V
V WIL
White Noise Insertion Level
See Figure 5
3.2
V
V BTH
Black Noise Threshold Voltage
1.3
V
V BIL
Black Noise Insertion Level
2.5
V
AGC CIRCUIT
I 24C
Charging Current
550
900
1200
m
A
I 24D
Discharge Current
12
20
26
m
A
C/D
Charging / Discharging Ratio
45
TUNER AGC
I 2
Sinked Current
1.2
1.9
2.6
mA
S 2
Current Slope
See FIgure 4
300
m A/dB
AFC
AFC Slope
See Figure 2, refer to test circuit
20
mV/kHz
FM SOUND DEMODULATION
V 16S
Input Sensitivity
-3dB FM detected signal
60
m
V
AMR
Amplitude Modulation Rejection Note 3
40
53
dB
R 16
Limiter Input Resistance
1.2
k
W
AUDIO OUTPUT (PIn 11)
V 11
Detected Audio Output Signal
500
mV RMS
THD
Total Harmonic Distortion
0.2
1
%
S
N
Signal to Noise Ratio
Note 4
68
dB
R 11
Internal Deemphasis Resistor
700
1000
1400
W
VOLUME CONTROL
V C range Control Range
See Figure 3
80
dB
Notes : 1.
at BW = 5MHz
2. Video carrier relative level = 0dB, Chroma subcarrier relative level = -3.2dB, Sound carrier relative level = -20dB.
3. AMR = 20 Log
S
N
= 20 Log 10
V OUT black to white
V N ( RMS )
V 11 (
mV RMS )
(dB) where V AM = output amplitude in AM for f m = 1kHz and m = 30%
V AM (
mV RMS )
4.
S
N
= 20 Log V 11 (
mV RMS )
(dB)
V N (
mV RMS )
4/9
11039366.005.png
TDA8222
ELECTRICAL CHARACTERISTICS (continued)
(T amb =25 o C, V CC = 9V, IF input = 10mV RMS top sync, D = 90%, Video BW = 5MHz,
Sound carrier input : 5.5MHz, 10mV RMS ,f m = 1kHz, Audio BW = 20kHz, D f= ± 25kHz,
Volume attenuation = 0dB, R load on Pin 12 = 1k W , unless otherwise specified)
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
AUDIO SWITCH
R 17
Input Resistance
40
65
k
W
C Rtk
Crosstalk
70
80
dB
EXTHD THD on External Signal
V IN =2V RMS , Attenuation = 0dB
0.05
0.3
%
VIDEO SWITCH
V DC 13-14 DC Input Level
No signal
1.6
1.9
2.2
V
V S 13 -14 Top Sync Clamp Level
1.8
V
V 12
DC Output Level
No signal
0.7
1.0
1.3
V
V S12
Top Sync Clamp Level
0.85
V
Crosstalk
55
dB
G 13-14 . 12 Gain from inputs to output
V IN =1V PP
5.5
6
6.5
dB
Output Swing
4.5
V
I 13-14
Input Current
V 13-14 =V DC 13-14 + 1.5V
1
5
m
A
VBW
Bandwidth
V IN =1V PP
15
MHz
SWITCHING INPUT
V 21 ext
External Input Selection Level
5
V
V 21 int
Internal Input Selection Level
2.5
I 21
Sourced Current
0
10
m
A
MUTE
V 15
Threshold Voltage
2.1
V
V 15
DC Level when mute disabled
High impedance controling circuit
2.8
V
5/9
11039366.001.png

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