TDA4483 Datasheet | TEMIC Semiconductors

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 ponents 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) 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 amplifier (AGC). The second mixer stage works as a intercarrier mixer in FM/NICAM mode and supplies the intercarrier signal at Pin 8 (difference signal between picture and sound carrier) independent of the picture carrier to sound carrier ratio. In standard B/G the 5.5/5.74 MHz subcarrier is available at Pin 8. The required picture carrier for the intercarrier mixer will be coupled out from the tuned demodulator circuit of the vision-IF IC (e.g. TDA4453 or equivalent ponents). The selective and prelimited picture carrier has to be applied symmetrically to the...