Description

The TDA4474 is an integrated bipolar circuit for full multistandard video/sound IF (VIF/SIF) signal processing in TV/VCR and Multimedia applications. The circuit processes all TV video IF signals with negative modulation (e.g. B/G standard), positive modulation (e.g. L standard) and the AM, FM/NICAM sound IF signals. Four IF inputs (2 x VIF plus 2 x SIF) and the common pinning with TDA4471 gives flexibility to design a universal IF module for various applications.

Features

● 5V supply voltage; low power consumption

● Active carrier generation by FPLL principle (frequency–phase–locked–loop) for true synchronous demodulation

● Very linear video demodulation, good pulse response and excellent intermodulation figures

● VCO circuit is operating on picture carrier frequency, the VCO frequency is switchable for the L’ mode

● Alignment–free AFC without external reference circuit, polarity of the AFC curve is switchable

● VIF–AGC for negative modulated signals (peak sync detection) and for positive modulation (peak white/black level detector)

● Tuner AGC with adjustable take over point

● Alignment–free quasi parallel sound (QPS) mixer for FM/NICAM sound IF signals

● Intercarrier output signal is gain controlled (necessary for digital sound processing)

● Complete alignment–free AM demodulator with gain controlled AF output

● Separate SIF–AGC with average detection

● Parallel operation of the AM demodulator and QPS mixer (for NICAM–L stereo sound)

● Four IF inputs (2 x VIFin and 2 x SIFin)

● Package and relevant pinning is compatible with the TDA4471; simplifies the design of an universal IF module