TDA4483
Intercarrier Mixer and AM-Demodulator for TV and VCR
Features
D Very high input sensitivity D Excellent signal-...
TDA4483
Intercarrier Mixer and AM-Demodulator for TV and VCR
Features
D Very high input sensitivity D Excellent signal-to-noise ratio D Intercarrier output signal gain controlled and independent from the picture carrier to sound carrier ratio
D Few external components D ESD protected
D AM demodulator alignment free
Case: DIP14
Block Diagram
AGC 7 14 +VS 13 1 IF Input sound carrier 2 10 4 Standard switch (AM / FM) 5 IF Input picture carrier 6 8 Intercarrier output (FM) 12 AF output (AM)
93 7481
Figure 1.
TELEFUNKEN Semiconductors Rev. A1, 15-May-96
1 (8)
TDA4483
Pin Description
1 Pin 1, 2 3, 9, 11 4, 13 5, 6 7 8 10 12 14 Function IF input (sound carrier) No connected Ground IF input (picture carrier) AGC time constant Intercarrier output Standard switch AF output (AM) Supply
voltage 2 3 4 5 6 7 14 13 12 11 10 9 8
Circuit Description
The bipolar circuit TDA4483 enables high quality sound IF processing for multistandard applications in TV-sets and VCR. This circuit has separate inputs for the soundand picture carrier. The sound carrier signal (single or dual carrier, modulated with AM, FM or NICAM) from the SAW filter will be fed into a 3-stage, gain controlled, IF amplifier (Pin 1 and 2). The following two mixer stages operate using different standards. In the case of AM, the first mixer works as a quasi-synchronous detector providing the audio frequency at Pin 12. Furthermore, the first mixer supplies a regulation
voltage to control the gain of the 3-stage IF ampli...