WM8778 w 24-bit, 192kHz Stereo CODEC DESCRIPTION FEATURES Audio Performance The WM8778 is a high performance, stereo audio CODEC. It is ideal for surround sound processing 108dB SNR (A weighted 48kHz) DAC applications for home hi-fi, DVD-RW and other audio 102dB SNR (A weighted 48kHz) ADC visual equipment. DAC Sampling Frequency: 32kHz 192kHz The stereo 24-bit multi-bit sigma delta ADC has ADC Sampling Frequency: 32kHz 96kHz programmable gain with automatic level control. Digital Stereo ADC input analogue gain adjust from +24dB to 21dB audio output word lengths from 16-32 bits and sampling in 0.5dB steps rates from 32kHz to 96kHz are supported. ADC digital gain from -21.5dB to -103dB in 0.5dB steps A stereo multi-bit sigma delta DAC is used with digital Programmable Automatic Level Control (ALC) or Limiter on audio input word lengths from 16-32 bits and sampling ADC input. rates from 32kHz to 192kHz. A multiplexor after the DAC Stereo DAC with analogue line outputs. allows the selection of either an external analogue input 3-Wire SPI Compatible or 2-wire Serial Control Interface or DAC playback into the line outputs. Hardware Control Mode The WM8778 supports fully independent sample rates Master or Slave Clocking Mode for the ADC and DAC. The audio data interface supports Programmable Audio Data Interface Modes 2 I S, left justified, right justified and DSP formats. 2 I S, Left, Right Justified or DSP The device is controlled in software via a 2 or 3 wire 16/20/24/32 bit Word Lengths serial interface which provides access to all features Analogue Bypass Path Feature including volume controls, mutes, and de-emphasis 2.7V to 5.5V Analogue, 2.7V to 3.6V Digital supply Operation facilities. It can also be controlled in hardware which gives access to the most commonly used features. Control interface selection is done via the MODE pin (tri- level). The device is available in a 28-lead SSOP APPLICATIONS package. Surround Sound AV Processors and Hi-Fi systems BLOCK DIAGRAM DVD-RW WOLFSON MICROELECTRONICS plc Production Data, July 2008, Rev 4.2 To receive regular email updates, sign up at WM8778 Production Data TABLE OF CONTENTS DESCRIPTION .......................................................................................................1 FEATURES.............................................................................................................1 APPLICATIONS .....................................................................................................1 BLOCK DIAGRAM .................................................................................................1 TABLE OF CONTENTS .........................................................................................2 PIN CONFIGURATION...........................................................................................3 ORDERING INFORMATION ..................................................................................3 ABSOLUTE MAXIMUM RATINGS.........................................................................5 ELECTRICAL CHARACTERISTICS ......................................................................6 TERMINOLOGY............................................................................................................ 7 MASTER CLOCK TIMING......................................................................................8 DIGITAL AUDIO INTERFACE MASTER MODE......................................................... 8 DIGITAL AUDIO INTERFACE SLAVE MODE ............................................................ 9 3-WIRE MPU INTERFACE TIMING ............................................................................ 11 CONTROL INTERFACE TIMING 2-WIRE MODE .................................................... 12 INTERNAL POWER ON RESET CIRCUIT ..........................................................13 DEVICE DESCRIPTION.......................................................................................15 INTRODUCTION......................................................................................................... 15 AUDIO DATA SAMPLING RATES............................................................................... 15 ZERO DETECT ........................................................................................................... 17 POWERDOWN MODES ............................................................................................. 17 DIGITAL AUDIO INTERFACE ..................................................................................... 17 CONTROL INTERFACE OPERATION........................................................................ 22 CONTROL INTERFACE REGISTERS ........................................................................ 24 LIMITER / AUTOMATIC LEVEL CONTROL (ALC)...................................................... 32 REGISTER MAP ......................................................................................................... 38 DIGITAL FILTER CHARACTERISTICS ...............................................................45 DAC FILTER RESPONSES......................................................................................... 45 ADC FILTER RESPONSES......................................................................................... 46 ADC HIGH PASS FILTER ........................................................................................... 46 DIGITAL DE-EMPHASIS CHARACTERISTICS........................................................... 47 APPLICATIONS INFORMATION .........................................................................48 RECOMMENDED EXTERNAL COMPONENTS.......................................................... 48 PACKAGE DIMENSIONS ....................................................................................50 IMPORTANT NOTICE ..........................................................................................51 ADDRESS: .................................................................................................................. 51 PD, Rev 4.2, July 2008 w 2