TDA4483

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...