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WM8608
5 to 7.1 Channel PWM Controller
DESCRIPTION
The WM8608 comprises a high performance multi-channel PWM digital power amplifier controller. Simply by adding appropriate power output stages a multi-channel power amplifier may be built. Six identical full audio bandwidth channels, plus a reduced bandwidth sub channel are provided as PWM outputs, to drive 6 speakers plus Sub.
The PCM to PWM converter supports up to 7.1 channels of audio, in PCM input formats. These may be mixed down to 6.1 or 5.1 outputs, by mixing rear channel data into centre rear or surround speakers if required. If 5.1 channel data is input, the surround data may be processed internally to create a pseudo 6.1 signal with rear channel output.
A Graphic Equaliser function is provided, plus selectable high frequency equalisation to suit different speaker types. Independent volume control for each channel is provided.
The WM8608 PWM controller is compatible with integrated switching output stages available from a number of vendors or alternatively may be used with a discrete output stage configuration and achieve similar levels of performance.
A Dynamic Peak Compressor with programmable attack and decay times is included, which allows headroom for tone control, bass management and extra digital gain to be provided, without clipping occurring.
A Synchroniser allows slaving to LRCLK, thus making the WM8608 independent of source MCLK frequency and jitter.
The device is controlled via a 2/3 wire serial interface. The interface provides access to all features including channel selection, volume controls, mutes, de-emphasis and power management facilities. The device is supplied in a 48-pin TQFP package.
FEATURES
• Multi-channel PWM audio amplifier controller • Supports Stereo, 5.1, 6.1 or 7.1 inputs • Supports 2.1, 5.1 or 6.1 outputs with optional rear centre
channel generation • PWM Audio Performance with typical output stage
− 100dB SNR (‘A’ weighted @ 48kHz) − 0.01% THD @ 1Watt − 0.1% THD @ 30Watt • Integrated Bass Management support with adjustable filter • Integrated 4-band Graphic Equaliser for 3 front channels • Adjustable output stage filter compensation for different speakers • Volume control on each 6.1 channel +24dB to -103.5dB in 0.5dB steps, with volume ramping and auto-mute functions • Programmable Dynamic Peak Compressor avoids clipping even at high volume settings • Internal PLL and optional crystal oscillator, supporting Audio and MPEG standards • 2/3-Wire MPU Serial Control Interface • Master or Slave Clocking Mode • Programmable Audio Data Interface Modes − I2S, Left, Right Justified or DSP − 16/20/24/32 bit Word Lengths • De-emphasis support for stereo • Selectable CMOS or LVDS digital outputs
APPLICATIONS
• Surround Sound AV Processors and Hi-Fi systems • Automotive Audio • DVD receivers
WOLFSON MICROELECTRONICS plc www.wolfsonmicro.com
Product Preview, March 2004, Rev 1.5
Copyright 2004 Wolfson Microelectronics plc
WM8608
Product Preview
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