The DSP-based analog TV IF demodulator DRX 396xA performs the entire multistandard TV IF processing, AGC, video demodulation, and generation of the sound IF (SIF), requiring only one SAW filter. The IC is designed for applications, such as TV sets, DVD recorders, PC cards, and TV tuners.

The alignment-free DRX 396xA does not need special external components. All control functions and status registers are accessible via I2C bus interface. Therefore, it simplifies the design of high-quality, highly standardized IF stages.

Due to its mixed-signal structure and the digital demodulation, the IC offers unique features and can easily be combined with digital TV applications. Thus, the DRX 396xA enables an economic hybrid solution for the reception of either analog or digital TV channels which requires only one tuner and one single SAW filter.

System Architecture

The down-converted and filtered analog IF signal is digitized for further digital signal processing. A digital PLL performs the tracking of the picture carrier and therefore synchronous demodulation.

Channel filtering is performed internally by digital filters. They also separate the video and sound components of the desired channel. The processing is competitive to conventional QSS systems.

The video AGC controls the CVBS amplitude. In positive modulation mode, an adaptive back porch control (BPC) is activated. The SIF AGC controls the level of the sound carrier output.

A Micronas video/audio processor (e.g. VCT 6wxyP, VPX 322xF, AVF 49xyA, and MSP 44xyG) can be connected to the CVBS and/or SIF output. Due to the internal filtering, no video or sound traps are needed.

Block diagram of the DRX 396xA

Main Features

Multistandard QSS IF processing with a single SAW filter

Programmable IF frequency between 30 and 60 MHz

DSP-based IF processing for the following standards: B/G, D/K, I, L/L’, and M/N

Standard specific digital signal processing for:

Channel filtering

Audio/video splitting

Group delay equalization (programmable)

Video AGC and delayed tuner AGC

Digital picture carrier recovery:

Field proven

Alignment-free

Stable frequency lock at overmodulation up to 150%

Quartz-accurate AFC information

Selectable bandwidth for different field conditions

Automatically frequency-adjusted Nyquist slope, providing optimum picture and sound performance over complete lock-in frequency range, which eliminates the need of fine tuning

Fast AGC algorithms for tuner, video, and SIF outputs

Field proven

Adaptive back porch control for positive modulation (L/L’)

Programmable tuner take-over point (TOP)

No sound traps required for video output

FM radio capability without external components and with standard TV tuner

Allows economic, single-tuner / single-SAW hybrid TV solution (DVB-C, DVB-T, ATSC)

I2C bus interface

PMQFP44-1 or PQFN64-1 package