The TDA9874A is a single-chip Digital TV Sound
Demodulator/Decoder (DTVSD) for analog and digital
multi-channel sound systems in TV/VCR sets and satellite
receivers.

The multi-standard/multi-stereo capability of the
TDA9874A is of interest in Europe, Hong Kong/PR China
and South East Asia. This includes B/G, D/K, I, M and
L standard. In other application areas subsets of the
standard combinations are available or, only single
standards are transmitted.
All A2 (analog 2-carrier) and NICAM systems are
supported. M standard (with mono or BTSC stereo sound)
can be received and processed in mono sound mode.
The AM sound of L/L’ standard is normally demodulated in
the 1st sound IF. The resulting AF signal has to be entered
into the mono audio input of the TDA9874A. A second
possibility is to use the internal AM demodulator stage
(with 6.5 MHz intercarrier), which gives limited
performance.
Korea has a stereo sound system similar to Europe and is
supported by the TDA9874A. The differences include
deviation, modulation contents and identification. It is
based on M standard.
For all FM standards a high deviation mode for a single
carrier monaural sound demodulation is selectable.
An overview of the supported standards and sound
systems and their key parameters is given in
Tables 1 to 3.
The analog multi-channel systems are sometimes also
called 2CS (2-carrier systems).