TDA8120B
MULTISTANDARD VIDEO AND SOUND IF SYSTEM
October 1993
.
GAIN CONTROLLED IF AMPLIFIER
.
VIF
OPERATING
FREQUENCY
UP
TO
50MHz
.
SYNCHRONOUS DETECTOR
.
WHITE SPOT INVERTER
.
VERY LOW DIFFERENTIAL ERROR
.
VERY LOW PHASE ERROR
.
INTERNAL AGC SWITCH (B/G - L)
.
AGC TOP. SYNCH. FOR STANDARD B/G
.
AGC TOP WHITE FOR STANDARD L
.
QUASI SPLIT SOUND FOR STANDARD B/G
.
SOUND DETECTOR FOR STANDARD L
.
VIDEO MUTING FACILITY
.
SEPARATED SOUND OUTPUT
.
OPERATES WITHOUT EXTERNAL GATING
PULSE
DESCRIPTION
The TDA8120B is a monolithic IC for TV video IF
and Sound IF amplification and demodulation that
can operate with all the TV standards.
The Video IF section can handle negative (B/G) or
positive (L) modulated video signals by means of
DC switching.
DIP24
(Plastic Package)
ORDER CODE : TDA8120B
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
24
23
22
21
11
12
AF AM OUT
CARRIER TUNING
SUPPLY VOLTAGE
2nd IF SOUND OUT (QSS)
GND
VIDEO OUTPUT
SUPPLY VOLTAGE
AGC TIME CONSTANT
CARRIER TUNING
V
S1
T
2V
T
2S
T
1S
V
S2
QSS OR AM INPUT
GND
VIDEO IF INPUT
STANDARD SWITCH
AGC TIME CONSTANT
AGC TIME CONSTANT
AGC TIME CONSTANT
AND VIDEO MUTING
TUNER AGC OUTPUT
TUNER AGC DELAY
T
1V
8120B-01.EPS
PIN CONNECTIONS
The Sound IF section acts as a Quasi Split Sound
(QSS) subsystem in B/G transmission and allows
a second Sound IF with high rejection of the video
information.
The DC switch can modify the Sound IF configura-
tion to process AM modulated Sound signals (L).
The TDA8120B is assembled in a 24 pin dual in line
power package.
1/6
22
18
16
17
11
12
4
9
14
13
10
19
20
21
23
24
1
5
6
2
3
8
7
15
VIDEO SECTION
SOUND SECTION
SSW
SSW
SSW
SSW
SSW
STANDARD
SWITCH
(B/G or L)
LIMITER
PHASE
SHIFTER
(0
or 180
)
VOLTAGE
REGULATION
WHITE SPOT INV.
NOISE INVERT
VIDEO PREAMP.
VIDEO
DEMOD.
AND BUFFER
VIF AMP
(3 STAGES)
AGC AMPLIF.
AND
AGC DELAY
TOP SYNC CLAMP
or TOP WHITE CLAMP
MIN. VIDEO DETECTOR
2nd SIF
DEMOD.
LIMITER
AND PHASE
SHIFTER (90
)
BUFFER
1st SIF AMP.
(3 STAGES)
AGC AMPLIF.
AND
AGC DELAY
AM or AGC
DETECTOR
LIMITER
8120B-02.EPS
BLOCK DIAGRAM
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
4
, V
9
Supply Voltage V
s
15
V
I
8
, I
5
, I
1
Video Out, QSS
out
, AF AM Out, DC Output Current
10
mA
I
22
, I
15
Pin 22 and Pin 15 Input Current
1
mA
P
to t
Total Power Dissipation (T
amb
= 70
C)
2
W
T
stg
, T
j
Storage and Junction Temperature
40 to 150
C
V
14
Voltage at Pin 14
V
s
8120B-01.TBL
THERMAL DATA
Symbol
Parameter
Value
Unit
R
th jamb
Thermal Resistance
Max
40
C/W
8120B-02.TBL
TDA8120B
2/6
ELECTRICAL CHARACTERISTICS (V
S
= 12V, T
amb
= 25
C)
Symbol
Parameter
Test Conditions
Min. Typ. Max.
Unit
VIDEO IF SECTION V
I
= 10 mV
RMS
(black field), F
O
= 38.9MHz ; unless otherwise specified
V
s
Supply Voltage (Pins 4 and 9)
10.8
12
13.2
V
I
s
Supply Current
V
I
= 0
120
mA
V
8 H
Top White Level
V
I
= 0, R
L
= 1.5k
5.5
6
6.5
V
V
8 L
Top Synchronous Level
2.7
3
3.3
V
V
8
Video Output B/G
Modulation Depth, D = 90%, R
L
= 1.5k
2.2
3
3.4
V
pp
V
8
Video Output L
R
L
= 1.5k
, M = 100%
2.2
3
3.4
V
pp
V
8
Video Output Variation between
Standards B/G and L
M = 100%
2
%
I
8
Output Current
R
L
= 1.5k
4
mA
I
8
Input Current
2
mA
I
14
Tuner AGC Current Capability
4.5
mA
S/N
Signal to Noise Ratio
B = 5MHz, D = 90%
50
dB
V
I
AGC Range
V
8
= 1dB, D = 90%
60
dB
B
Bandwidth
V
8
= 3dB, D = 90%
7
MHz
V
1617
Input Sensitivity for Full Output
Signal
D = 90%
50
V
V
8
Carrier Leakages
F
o
= 38.9MHz
F
o
= 77.8MHz
20
50
mV
mV
dG
Differential Gain
Subcarrier Modulated Staircase Video
Signal, D = 90%
10
%
d
Differential Phase
Subcarrier Modulated Staircase Video
Signal, D = 90%
10
degree
d
IM
Intermodulation Product
1.07MHz
Video Carrier Relative Level = 0dB
Chroma Subcarrier Relative Level = 3.2dB
Sound Carrier Relative Level = 20dB
50
dB
R
i
Input Resistance
(between Pins 16 and pin 17)
1.5
k
C
i
Input Capacitance
(between Pins 16 and pin 17)
2
pF
QUASI SPLIT SOUND CHANNEL OR FRENCH SOUND CHANNEL (see notes 1 and 2)
V
2021
Input Sensitivity for Full Output
Signal (between Pins 20 and 21)
R Channel Missing
50
V
V
i
AGC Range
V
5
= 1dB, R Channel Missing
60
dB
V
5
Output Voltage Standard B/G
R
L
= 600
, AC Coupled, F
O
= 5.5MHz
100
mV
RMS
I
5
Output Current
2.5
mA
Z
5
Small Signal Output Impedance
(QSS)
F
O
= 5.5MHz or F
O
= 5.74MHz
50
k
R
i
Input Resistance
(between Pin 21 and Pin 20)
1.5
k
C
i
Input Capacitance
(between Pin 21 and Pin 20)
2
pF
S/N
Noise Ratio QSS (after SIF
limitation and FM demodulation)
F
O
= 5.50MHz
F
O
= 5.74MHz
Channel R or Channel L Switched off
F
m
= 1kHz,
f =
30kHz
Carrier Modulated with Syncs. Pulses Only.
CCIR 468-2 Recommendant
60
58
dB
V
1
Output Voltage Standard L
0.58
0.7
1
V
RMS
I
1
Output Current
2.5
mA
Z
1
AF Output Impedance (L)
50
S/N
Noise Ratio AM Standard L
B
N
= 20kHz
46
dB
8120B-03.TBL
TDA8120B
3/6
C1
1
2
3
4
5
6
24
23
22
21
20
19
18
7
17
16
8
9
15
10
11
14
12
13
C2
C3
C4
L2
38.9 or 32.7MHz
VIDEO OUT
5.50MHz OUT
5.74MHz OUT
AF AM OUT
38.9MHz
V
S
V
15
V
22
TDA8120B
C7
C6
C5
VIF
QSS (B/G)
or AM (L)
SAW FILTER
IF IN
AGC
OUT
P1
AGC delay adj.
C8
8120B-03.EPS
TEST CIRCUIT
ELECTRICAL CHARACTERISTICS (continued)
Symbol
Parameter
Test Condition s
Min.
Typ.
Max.
Unit
QUASI SPLIT SOUND CHANNEL OR FRENCH SOUND CHANNEL (see notes 1 and 2)
d
Distorsion
2
%
V
22
B/G Operation
L Operation
2
0
5
0.8
V
V
V
15
Video Muting
8
V
S
V
8120B-04.TBL
Notes : 1. QUASI SPLIT SOUND CHANN EL
Video carrier relative level = 0dB
f = 38.9MHz
f = 0
Sound carrier relative level = 13dB (mono or L)
f = 33.4MHz
Sound carrier relative level = -20dB (R)
f = 33.16MHz
V
I
= 10mV Video carrier modulated with syncs ; V
22
= 2V, unless otherwise specified.
2. FRENCH SOUND CHANNEL
V
I
= 10mV (Carrier level) ; f
o
= 39.2MHz ; F
m
= 1kHz ; m = 80% ; V
22
= 0.8V, unless otherwise specified.
TDA8120B
4/6
The TDA8120B (see block diagram) consists of a
video section and a sound section. The integration
of both sections on the same chip requires a high
isolation at IF frequencies. This is achieved by
physically separating the two sections, with sepa-
rate power supplies and ground pins. In addition,
special care has been taken in the choice of pad
positions for the IF inputs and sound/video outputs.
The video section consists of three AC-coupled IF
stages with more than 60dB AGC range, flat ampli-
tude/frequency response from 10 to 85MHz and
linearized phase slope from 30 to 50MHz. Video
carrier regeneration is performed by a tuned limiter.
The carrier is then applied to the video demodulator
through a special circuit which switches the carrier
phase from 0 to 180
so that the video polarity can
be maintained constant when the standard
switches from B/G to L. A noise inverter and a white
spot inverter are included to eliminate ultra-black
and white pulses.
A top sync or a top white clamping circuit and a
minimum DC video component detector are imple-
mented by two double comparators the charac-
teristics of which may be controlled by an external
control input to adapt to the modulation type for
each standard. The voltage at the output of the two
comparatorsis memorized by an external capacitor
and used to drive the AGC network, which allows
an input regulation of the video carrier from less
than 100
V to 100mV. A delayed control storage
with current output for the turner AGC completes
the video section.
The sound section consists of three IF stages with
the same characteristics as the video IF stages and
an identical network to control and set the gains of
the three IF amplifiers. The output of the third IF
stage feeds the AM/AGC detector and the QSS
section.
The AM/AGC detector consists of a wideband
limiter for AM sound regeneration or video carrier
regeneration used to feed the synchronous multi-
plier and consequently to obtain the AM demodu-
lated audio signal. In addition, a DC voltage
proportional to the peak-to-peak value of the video
carrier is produced. Two comparators complete the
sound AGC loop.
The subsequent QSS section consists of a refer-
ence amplifier tuned to the video IF which buffers
a wideband limiter to reject completely the video
AM information withou t introducing incidental
phase modulation (IPM).
Following the limiter there are a 90
phase shifter
and a linear-to-logarithmic converter which drives
a linear multiplier as a demodulator for the intercar-
rier 2nd sound IF. This quadrature multiplier rejects
all video components transmitted in DSB that is low
frequency components of the video signal.
In addition to the sound and video sections, the
TDA8120B includes a block for standard switching
(B/G or L) controlled by a TTL-compatible input.
CIRCUIT OPERATION
TDA8120B
5/6
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility
for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result
from its use. No licence is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics.
Specifications mentioned in this publication are subject to change without noti ce. This publication supersedes and replaces all
information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life
support devices or systems without express written approval of SGS-THOMSON Microelectronics.
1994 SGS-THOMSON Microelectronics - All Rights Reserved
Purchase of I
2
C Components of SGS-THOMSON Microelectronics, conveys a license under the Philips
I
2
C Patent. Rights to use these components in a I
2
C system, is granted provided that the system confo rms to
the I
2
C Standard Specifications as defined by Philips.
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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24
I
a1
L
b2
e
D
e3
F
b1
E
13
1
12
b
PM-DIP24.EPS
PACKAGE MECHANICAL DATA
24 PINS - PLASTIC DIP
Dimensions
Millimeters
Inches
Min.
Typ.
Max.
Min.
Typ.
Max.
a1
0.63
0.025
b
0.45
0.018
b1
0.23
0.31
0.009
0.012
b2
1.27
0.050
D
32.2
1.268
E
15.2
16.68
0.598
0.657
e
2.54
0.100
e3
27.94
1.100
F
14.1
0.555
i
4.445
0.175
L
3.3
0.130
DIP24.TBL
TDA8120B
6/6
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