Pre-Production
WM8985
TABLE OF CONTENTS
DESCRIPTION .......................................................................................................1
FEATURES.............................................................................................................1
APPLICATIONS .....................................................................................................1
BLOCK DIAGRAM .................................................................................................2
PIN CONFIGURATION...........................................................................................5
ORDERING INFORMATION ..................................................................................5
PIN DESCRIPTION ................................................................................................6
ABSOLUTE MAXIMUM RATINGS.........................................................................7
RECOMMENDED OPERATING CONDITIONS .....................................................7
ELECTRICAL CHARACTERISTICS ......................................................................8
TERMINOLOGY.......................................................................................................... 14
AUDIO PATHS OVERVIEW.................................................................................16
SIGNAL TIMING REQUIREMENTS.....................................................................17
SYSTEM CLOCK TIMING ........................................................................................... 17
AUDIO INTERFACE TIMING – MASTER MODE ........................................................ 17
AUDIO INTERFACE TIMING – SLAVE MODE............................................................ 18
CONTROL INTERFACE TIMING – 3-WIRE MODE .................................................... 19
CONTROL INTERFACE TIMING – 2-WIRE MODE .................................................... 20
INTERNAL POWER ON RESET CIRCUIT ..........................................................21
RECOMMENDED POWER UP/DOWN SEQUENCE .................................................. 23
DEVICE DESCRIPTION.......................................................................................27
INTRODUCTION......................................................................................................... 27
INPUT SIGNAL PATH................................................................................................. 28
ANALOGUE TO DIGITAL CONVERTER (ADC).......................................................... 38
INPUT LIMITER / AUTOMATIC LEVEL CONTROL (ALC) .......................................... 42
LIMITER MODE........................................................................................................... 45
OUTPUT SIGNAL PATH ............................................................................................. 54
3D STEREO ENHANCEMENT.................................................................................... 61
ANALOGUE OUTPUTS............................................................................................... 61
DIGITAL AUDIO INTERFACES................................................................................... 74
AUDIO SAMPLE RATES............................................................................................. 78
MASTER CLOCK AND PHASE LOCKED LOOP (PLL)............................................... 79
COMPANDING............................................................................................................ 81
GENERAL PURPOSE INPUT/OUTPUT...................................................................... 83
OUTPUT SWITCHING (JACK DETECT)..................................................................... 84
CONTROL INTERFACE.............................................................................................. 85
RESETTING THE CHIP .............................................................................................. 86
POWER SUPPLIES .................................................................................................... 86
POWER MANAGEMENT ............................................................................................ 87
REGISTER MAP...................................................................................................89
REGISTER BITS BY ADDRESS ................................................................................. 91
DIGITAL FILTER CHARACTERISTICS.............................................................109
TERMINOLOGY........................................................................................................ 109
DAC FILTER RESPONSES....................................................................................... 110
ADC FILTER RESPONSES....................................................................................... 110
HIGHPASS FILTER................................................................................................... 111
5-BAND EQUALISER................................................................................................ 112
PP, Rev 3.4, October 2006
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
