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Video and Sound IF
with V & S SCART
Features
● Features video / sound scart
● Active FM-PLL demodulator
● AF control
● Alignment - free sound IF
P-DIP-24-2
Type Ordering Code Package
TDA 5940-2
Bipolar IC
TDA 5940-2 Q67000-A5144 P-DIP-24-2
Functional Description and Application
Video IF Section
Video IF-broadband amplifier followed by a quasi-synchronous demodulator for negative
modulated IF signals. A Full-SCART interface is included in the video section. A separate video
output after the demodulator permits the installation of one or more sound traps at the input of the
SCART switch. The tuner AGC threshold is set by means of a potentiometer, all other functions can
switched with open collector transistors.
Sound IF Section
FM-IF limiter with FM-PLL demodulator. The AF section has a Full-SCART switch followed by a
volume control. The volume is controlled by an analog voltage.
Application
The TDA 5940-2 is suitable for application in television receivers with Full-SCART.
Semiconductor Group 44 06.94
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TDA 5940-2
Circuit Description
Video IF Section
The video IF section incorporates a four-stage, capacitively coupled, symmetrical and controlled
amplifier, a limiter with selection and a mixer for quasi-synchronous demodulation of negative
modulated IF signals followed by a video output amplifier. The video demodulator output and the
SCART-switch input are connected by means of a sound trap. The SCART switch has two inputs
(for signals from video demodulator and SCART socket) and two outputs (SCART socket and TV
output). Parallel to the video output amplifier the video signal is used for generating the AGC
voltage. The control circuit is designed on the integralaction AGC principle, employing a noise-free
peak value detector. A delayed tuner AGC voltage with positive control direction is derived from the
AGC -voltage via a threshold amplifier that is set by means of an external potentiometer.
Sound IF Section
The sound IF section incorporates a five-stage, symmetrical limiter amplifier followed by a PLL
demodulator. The AF section contains an analog switch for the Full-SCART interface and a volume
control with AF output.
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Pin Functions
Pin No. Function
1 Video IF input
2 Video IF input
3 Low-pass capacitor
4 De-emphasis capacitor
5 Audio SCART output
6 Audio output
7 Audio SCART input
8 Audio volume control
9 Sound IF input
10 Ground
TDA 5940-2
TDA 5940-2
11 Video demodulator output
12 Video input at sound trap output
13 Demodulator tank circuit
14 Demodulator tank circuit
15 MUTE control
16 Video SCART input
17 Video output
18 Video SCART output
19 +
20 Ground
21 SCART control
22 AGC-time constant
23 Delayed tuner AGC threshold
24 Delayed tuner AGC output
V
supply voltage
S
Semiconductor Group 46
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TDA 5940-2
Block Diagram
Semiconductor Group 47
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TDA 5940-2
Absolute Maximum Ratings
T
= 0 to 85 ˚C
A
Parameter Symbol Limit Values Unit
min. max.
Supply voltage V
Junction temperature
Storage temperature
Thermal resistance
Operating Range
Supply voltage
Supply voltage delayed tuner AGC
Ambient temperature during operation
Input frequency range
T
T
R
V
V
T
f
IF
S
j
stg
th JA
S
1
A
13.2 V
150 ˚C
125 ˚C
70 K/W
7.5 13.2 V
110V
085˚C
12 80 MHz
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TDA 5940-2
Characteristics
T
= 0 to 85 ˚C; VS = 12 V
A
Parameter Symbol Limit Values Unit Test Condition
min. typ. max.
Total current I
SCART Switch
H/open = SCART = Pb
L = RF
Volume Control Voltage
Minimal volume
Maximal volume
MUTE Voltage
H/open = AF ON
L = AF MUTE
Dynamic Parameter
19
V
21
V
21
V
8
V
8
V
15
V
15
2
0
0
2
0
46 mA
5
1.5
V
V
V
3.6 5
5
1.5
V
V
V
Video IF Section
IF-input sensitivity
Max. IF-input voltage
IF-control range ∆
Video demodulator
output voltage
Gain of SCART Switch
SCART/Video output
Video/SCART output
Video/Video output
Cross talk attenuation
V
V
V
G
G
G
a
1/2
1/2
V
IF
11pp
16-17
12-18
12-17
70 100 µV V
100 140 mV V
66 dB
1.35 1.5 1.65 V V
2
– 1
2
50 dB fIN = 0 … 5 MHz
Video
Video
IF IN
– 3 dB
+ 3 dB
= 10 mV
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TDA 5940-2
Characteristics (cont’d)
Parameter Symbol Limit Values Unit Test Condition
min. typ. max.
Sound IF Section
Min. sound IF-input voltage
V
9
70 µV
(min. control)
AF-output voltage
SCART AF-output voltage
Total harmonic distortion
Max. SCART-input voltage
Gain SCART-sound switch
V
6
V
5
THD
V
7RMS
G
7-6
AFo
500 mV ∆f = 30 kHz
f
= 1 kHz
mod
F
= 5.5 MHz
SIF
500 mV ∆f = 30 kHz
f
= 1 kHz
mod
F
= 5.5 MHz
SIF
0.5 % ∆f = 30 kHz
f
= 1 kHz
mod
F
= 5.5 MHz
SIF
2V
1 V8≥ 3.6 V
Alignment Instructions
V
At a video carrier input level of
of V22 = 1.5 V, the demodulator tank circuit is preliminarily aligned until a max. video signal V
= 4 mVrms, fPC = 38.9 MHz, and a superimposed AGC voltage
1/2
11pp
is
obtained at the video output. Any suitable video test signal can be used for modulation. The AGC
voltage V22 is reduced until the signal is approx. 1 Vpp and the max. video signal is obtained when
fine-aligning the demodulator tank circuit. The alignment is not critical due to relatively large
bandwidth of the demodulator tank circuit. Fine-tuning to intercarrier S/N, differential phase or
2T-pulse characteristics is possible.
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TDA 5940-2
Test Circuit
Semiconductor Group 51
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TDA 5940-2
Application Circuit
Semiconductor Group 52
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