TDA9874A

General description

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.

Supported standards

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 standards. In other application areas there exist subsets of the standard combinations 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 which is supported by the TDA9874A. 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, sound systems and their key parameters is given in Tables 1 to 3.

The analog multi-channel systems are sometimes also referred to as 2-carrier systems (2CS).

Features

• Sound IF (SIF) input switch
• SIF Automatic Gain Control (AGC) with 24 dB control range
• Switchable 10 dB SIF input attenuator
• SIF 8-bit Analog-to-Digital Converter (ADC)
• Easy TV standard programming option
• Differential Quadrature Phase Shift Keying (DQPSK) demodulation for different standards, simultaneously with 1-channel FM demodulation
• Near Instantaneous Companded Audio Multiplex (NICAM) decoding (B/G, D/K, I and L standard)
• 2-carrier multi-standard FM demodulation (B/G, D/K, I and M standard)
• Single carrier high deviation FM mono demodulation mode
• Decoding for three analog multi-channel systems (A2) and satellite sound
• Adaptive de-emphasis for satellite
• Programmable identification (B/G, D/K and M standard) and different identification times
• FM pilot carrier presence detector
• Optional AM demodulation for L standard, simultaneously with NICAM
• Monitor selection for FM/AM demodulator outputs and FM and NICAM signals with peak option
• Automatic FM dematrixing option
• Digital crossbar switch
• I²S-bus serial audio output with matrix, level adjust and mute
• Dual audio Digital-to-Analog Converter (DAC) from digital crossbar switch to analog crossbar switch, bandwidth 15 kHz
• Automatic Volume Level (AVL) control
• Analog crossbar switch with inputs for mono and stereo
• Output selection of mono, stereo, dual, dual A or dual B
• Additional mono output with automatic select
• 20 kHz bandwidth for analog path
• Standby mode
• Automatic output selection for TV applications.

Applications

• Relay driver
• High speed line driver
• Logic level translator.

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Disclaimers

• General product disclaimer
• Quality and reliability disclaimer