WM8731 / WM8731L w Portable Internet Audio CODEC with Headphone Driver and Programmable Sample Rates DESCRIPTION FEATURES Highly Efficient Headphone Driver The WM8731 or WM8731L (WM8731/L) are low power stereo CODECs with an integrated headphone driver. The Audio Performance WM8731/L is designed specifically for portable MP3 audio - ADC SNR 90dB (A weighted) at 3.3V, 85dB at 1.8V and speech players and recorders. The WM8731 is also - DAC SNR 100dB (A weighted) at 3.3V, 95dB at 1.8V ideal for MD, CD-RW machines and DAT recorders. Low Power - Playback only 22mW, 8mW (L Variant) Stereo line and mono microphone level audio inputs are - Analogue Pass Through 12mW, 3.5mW (L variant) provided, along with a mute function, programmable line - 1.42 3.6V Digital Supply Operation level volume control and a bias voltage output suitable for an electret type microphone. - 2.7 3.6V Analogue Supply Operation - 1.8 3.6V Analogue Supply Operation (L Variant) Stereo 24-bit multi-bit sigma delta ADCs and DACs are used ADC and DAC Sampling Frequency: 8kHz 96kHz with oversampling digital interpolation and decimation filters. Selectable ADC High Pass Filter Digital audio input word lengths from 16-32 bits and 2 or 3-Wire MPU Serial Control Interface sampling rates from 8kHz to 96kHz are supported. Programmable Audio Data Interface Modes Stereo audio outputs are buffered for driving headphones 2 - I S, Left, Right Justified or DSP from a programmable volume control, line level outputs are - 16/20/24/32 bit Word Lengths also provided along with anti-thump mute and power - Master or Slave Clocking Mode up/down circuitry. Microphone Input and Electret Bias with Side Tone Mixer The device is controlled via a 2 or 3 wire serial interface. Available in 28-lead SSOP or 28-lead QFN package The interface provides access to all features including volume controls, mutes, de-emphasis and extensive power APPLICATIONS management facilities. The device is available in a small 28- Portable MP3 Players and Recorders lead SSOP package or the smaller 28 lead quad flat leadless package (QFN). CD and Minidisc Recorders PDAs / smartphones BLOCK DIAGRAM AVDD W CONTROL INTERFACE WM8731 VMID HPVDD Bypass MUTE HPGND AGND ATTEN / +6 to -73 dB MUTE 1 dB Steps Side Tone VOL / H/P MICBIAS RHPOUT DRIVER MUTE RLINEIN VOL MUTE MUX ADC DAC MUTE MUTE + 12 to -34.5dB , 1.5dB Steps ROUT 0dB / DIGITAL MICIN 20 dB FILTERS LOUT MUTE MUX DAC MUTE ADC VOL MUTE LLINEIN VOL / H/P LHPOUT + 12 to -34.5dB , 1.5dB MUTE DRIVER Steps Side Tone +6 to -73 dB ATTEN / 1 dB Steps MUTE MUTE CLKIN CLKOUT DIGTAL AUDIO INTERFACE Bypass OSC DIVIDER DIVIDER ( Div x 1 , x2) ( Div x 1 , x2) Production Data, October 2012, Rev 4.9 WOLFSON MICROELECTRONICS plc Copyright 2012 Wolfson Microelectronics plc XTO XTI/MCLK CLKOUT DACDAT CSB DACLRC SDIN SCLK BCLK MODE ADCLRC ADCDAT DCVDD DBVDD DGNDWM8731 / WM8731L Production Data TABLE OF CONTENTS DESCRIPTION ....................................................................................................... 1 FEATURES ............................................................................................................ 1 APPLICATIONS ..................................................................................................... 1 BLOCK DIAGRAM ................................................................................................ 1 PIN CONFIGURATION - 28 PIN SSOP ................................................................ 3 ORDERING INFORMATION .................................................................................. 3 PIN CONFIGURATION 28 PIN QFN ................................................................... 4 ORDERING INFORMATION .................................................................................. 4 PIN DESCRIPTION ................................................................................................ 5 ABSOLUTE MAXIMUM RATINGS ........................................................................ 6 RECOMMENDED OPERATING CONDITIONS WM8731 .................................. 6 RECOMMENDED OPERATING CONDITIONS WM8731L ................................ 6 ELECTRICAL CHARACTERISTICS WM8731 ................................................... 7 TERMINOLOGY .............................................................................................................. 9 POWER CONSUMPTION WM8731 .................................................................. 10 ELECTRICAL CHARACTERISTICS WM8731L ............................................... 11 TERMINOLOGY ............................................................................................................ 13 POWER CONSUMPTION WM8731L ............................................................... 14 MASTER CLOCK TIMING ................................................................................... 15 DIGITAL AUDIO INTERFACE MASTER MODE ........................................................ 16 DIGITAL AUDIO INTERFACE SLAVE MODE ............................................................ 17 MPU INTERFACE TIMING ............................................................................................ 18 DEVICE DESCRIPTION ...................................................................................... 20 INTRODUCTION ........................................................................................................... 20 AUDIO SIGNAL PATH ................................................................................................... 21 DEVICE OPERATION ................................................................................................... 34 AUDIO DATA SAMPLING RATES ................................................................................ 41 ACTIVATING DSP AND DIGITAL AUDIO INTERFACE ................................................ 45 SOFTWARE CONTROL INTERFACE ........................................................................... 45 POWER DOWN MODES ............................................................................................... 47 REGISTER MAP ............................................................................................................ 49 DIGITAL FILTER CHARACTERISTICS .............................................................. 54 TERMINOLOGY ............................................................................................................ 55 DAC FILTER RESPONSES ................................................................................. 56 ADC FILTER RESPONSES ................................................................................. 57 ADC HIGH PASS FILTER ............................................................................................. 58 DIGITAL DE-EMPHASIS CHARACTERISTICS .................................................. 58 DIGITAL DE-EMPHASIS CHARACTERISTICS .................................................. 59 APPLICATIONS INFORMATION ........................................................................ 60 RECOMMENDED EXTERNAL COMPONENTS ........................................................... 60 MINIMISING POP NOISE AT THE ANALOGUE OUTPUTS ......................................... 61 PACKAGE DIMENSIONS - SSOP ....................................................................... 62 PACKAGE DIMENSIONS - QFN ......................................................................... 63 IMPORTANT NOTICE ......................................................................................... 64 ADDRESS: .................................................................................................................... 64 PD, Rev 4.9, October 2012 w 2