WM8945
Production Data
TABLE OF CONTENTS
DESCRIPTION....................................................................................................... 1
FEATURES............................................................................................................ 1
APPLICATIONS..................................................................................................... 1
TABLE OF CONTENTS......................................................................................... 2
BLOCK DIAGRAM ................................................................................................ 5
PIN CONFIGURATION.......................................................................................... 6
ORDERING INFORMATION.................................................................................. 6
PIN DESCRIPTION................................................................................................ 7
ABSOLUTE MAXIMUM RATINGS........................................................................ 8
RECOMMENDED OPERATING CONDITIONS..................................................... 8
THERMAL PERFORMANCE................................................................................. 9
ELECTRICAL CHARACTERISTICS ................................................................... 10
TERMINOLOGY............................................................................................................. 13
TYPICAL PERFORMANCE................................................................................. 14
POWER CONSUMPTION.............................................................................................. 15
AUDIO SIGNAL PATHS DIAGRAM.................................................................... 16
SIGNAL TIMING REQUIREMENTS .................................................................... 17
SYSTEM CLOCK TIMING.............................................................................................. 17
AUDIO INTERFACE TIMING ......................................................................................... 17
MASTER MODE........................................................................................................................................17
SLAVE MODE ...........................................................................................................................................18
CONTROL INTERFACE TIMING................................................................................... 19
DEVICE DESCRIPTION ...................................................................................... 22
INTRODUCTION............................................................................................................ 22
ANALOGUE INPUT SIGNAL PATH............................................................................... 23
INPUT PGA ENABLE ................................................................................................................................24
INPUT PGA CONFIGURATION ................................................................................................................24
MICROPHONE BIAS CONTROL ..............................................................................................................25
INPUT PGA GAIN CONTROL...................................................................................................................25
DIGITAL MICROPHONE INTERFACE .......................................................................... 27
ANALOGUE-TO-DIGITAL CONVERTER (ADC)............................................................ 28
ADC VOLUME CONTROL.........................................................................................................................28
ADC HIGH PASS FILTER .........................................................................................................................31
DSP CORE.....................................................................................................................32
DSP CONFIGURATION MODES ..............................................................................................................32
LOW-PASS / HIGH-PASS FILTER (LPF/HPF)..........................................................................................33
5-NOTCH FILTER .....................................................................................................................................34
DF1 FILTER...............................................................................................................................................35
RETUNETM FILTER ...................................................................................................................................35
5-BAND EQ ...............................................................................................................................................36
DYNAMIC RANGE CONTROL (DRC).......................................................................................................36
SIGNAL ENHANCEMENT REGISTER CONTROLS.................................................................................36
DYNAMIC RANGE CONTROL (DRC) ........................................................................... 37
DRC COMPRESSION / EXPANSION / LIMITING.....................................................................................38
GAIN LIMITS .............................................................................................................................................40
GAIN READBACK .....................................................................................................................................41
DYNAMIC CHARACTERISTICS ...............................................................................................................42
ANTI-CLIP CONTROL...............................................................................................................................43
QUICK-RELEASE CONTROL ...................................................................................................................44
DRC INITIAL VALUE.................................................................................................................................44
PD, May 2011, Rev 4.1
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
