Video and Sound IF with FM-PLL
Demodulator, AFC and V & S SCART
Bipolar IC
TDA 5950X
P-DSO-24-1
Functional Description
Video IF Section
Video IF-broadband amplifier followed by a quasi-synchronous demodulator for negative
modulated IF signals. A video switch 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
video 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 for the frequency range of 5.5 MHz to 6.5 MHz. The AF
section includes an audio switch followed by an audio buffer output.
Application
The TDA 5950X is suitable for application in television receivers or video tape recorders with A/V
switches.
Type
Ordering Code
Package
TDA 5950X
Q67000-A5112
P-DSO-24-1 (SMD)
TDA 5950X
Q67007-A5112
P-DSO-24-1 Tape and Reel dry
Semiconductor Group
1
12.94
Features
q
Features video and sound IF
q
Video and sound SCART
q
AFC
q
NTSC option
Semiconductor Group
2
TDA 5950X
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
video switch input are connected by means of a sound trap. The video switch has two inputs (for
signals from video demodulator and from external source) and two outputs. 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. An AFC push pull output
current is generated from picture carrier tank circuit.
Sound IF Section
The sound IF section incorporates a five-stage, symmetrical limiter amplifier followed by a PLL
demodulator. The AF section contains an audio switch followed by an output buffer.
Switch Matrix
AUX/RF-Control
(Pin 4)
AV-OFF
(Pin 17)
Output
(Pin 8 / Pin 19)
0
0
muted
0
1
IF
1
0
muted
1
1
SCART
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