GENERAL DESCRIPTION

Performing all digital decoding functions for a NICAM 728 digital stereo sound system, the SAA7282 is a highly integrated CMOS circuit which only requires a DQPSK (Differential Quadrature Phase Shift Keying) demodulator (TDA8732) and minimum external components to achieve a full NICAM solution.

The device may also be interfaced to other DQPSK demodulators.

FEATURES

• Full EBU NICAM 728 specification decoder

• Microcomputer controlled via I2C-bus

• Automatic decoding and output configuration depending upon transmission:

– digital stereo

– digital mono and data

– 2 independent mono signals

• On board RAM for de-interleaving and 10 to 14-bit word expansion

• Automatic mute function which silences the digital data and switches to FM sound (if valid) when error rate exceeds user definable limit

• User mute function (MUTE pin) to enable user to perform muting to their own software algorithm if required, or to simply silence the output

• 4 times over-sampling digital filter

• Selectable digital de-emphasis

• 256 times over-sampling Noise Shapers

• Fully integrated 1-bit DACs

• Integrated switching networks allowing selection between NICAM Sound, FM Sound or external “Daisy-Chain” input

• Digital Audio Interface conforming with EBU/IEC 958

• I2C-bus transceiver enabling a master device to read

– status information

– error count byte

– additional data bits and write:

– switch control codes

– decoder control

– upper and lower error rate limits.

APPLICATIONS

• Television receivers

• Video cassette recorders.