Pre-Production
WM8940
TABLE OF CONTENTS
DESCRIPTION .......................................................................................................1
FEATURES.............................................................................................................1
APPLICATIONS .....................................................................................................1
BLOCK DIAGRAM .................................................................................................2
TABLE OF CONTENTS .........................................................................................3
PIN CONFIGURATION...........................................................................................5
ORDERING INFORMATION ..................................................................................5
PIN DESCRIPTION ................................................................................................6
ABSOLUTE MAXIMUM RATINGS.........................................................................7
RECOMMENDED OPERATING CONDITIONS .....................................................7
ELECTRICAL CHARACTERISTICS ......................................................................8
TERMINOLOGY.......................................................................................................... 10
POWER CONSUMPTION ....................................................................................11
SIGNAL TIMING REQUIREMENTS.....................................................................12
SYSTEM CLOCK TIMING ........................................................................................... 12
AUDIO INTERFACE TIMING – MASTER MODE ........................................................ 12
AUDIO INTERFACE TIMING – SLAVE MODE............................................................ 13
CONTROL INTERFACE TIMING – 3-WIRE MODE .................................................... 14
CONTROL INTERFACE TIMING – 2-WIRE MODE .................................................... 15
DEVICE DESCRIPTION.......................................................................................16
INTRODUCTION......................................................................................................... 16
INPUT SIGNAL PATH................................................................................................. 17
ANALOGUE TO DIGITAL CONVERTER (ADC).......................................................... 22
INPUT LIMITER / AUTOMATIC LEVEL CONTROL (ALC) .......................................... 27
OUTPUT SIGNAL PATH ............................................................................................. 40
ANALOGUE OUTPUTS............................................................................................... 44
OUTPUT SWITCH ...................................................................................................... 47
DIGITAL AUDIO INTERFACES................................................................................... 50
AUDIO SAMPLE RATES............................................................................................. 54
MASTER CLOCK AND PHASE LOCKED LOOP (PLL)............................................... 54
COMPANDING............................................................................................................ 57
GENERAL PURPOSE INPUT/OUTPUT...................................................................... 59
CONTROL INTERFACE.............................................................................................. 59
3-WIRE SERIAL CONTROL MODE ............................................................................ 61
READBACK IN 3-WIRE MODE ................................................................................... 61
2-WIRE SERIAL CONTROL MODE ............................................................................ 62
RESETTING THE CHIP .............................................................................................. 62
POWER SUPPLIES .................................................................................................... 62
POWER MANAGEMENT ............................................................................................ 64
POP MINIMISATION ................................................................................................... 65
REGISTER MAP...................................................................................................66
REGISTER BITS BY ADDRESS ................................................................................. 67
DIGITAL FILTER CHARACTERISTICS...............................................................78
TERMINOLOGY.......................................................................................................... 78
DAC FILTER RESPONSES......................................................................................... 79
ADC FILTER RESPONSES......................................................................................... 79
HIGHPASS FILTER..................................................................................................... 80
NOTCH FILTERS AND LOW PASS FILTER............................................................... 81
Pre-Production, Rev 3.0, February 2007
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
