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.