WM8731LSEFL Wolfson Microelectronics, WM8731LSEFL Datasheet
WM8731LSEFL
Specifications of WM8731LSEFL
Available stocks
Related parts for WM8731LSEFL
WM8731LSEFL Summary of contents
Page 1
... Microphone Input and Electret Bias with Side Tone Mixer • Available in 28-lead SSOP or 28-lead QFN package APPLICATIONS • Portable MP3 Players and Recorders • CD and Minidisc Recorders • PDAs / smartphones http://www.wolfsonmicro.com/enews/ (‘A’ weighted) at 3.3V, 95dB at 1.8V Production Data, April 2009, Rev 4.8 Copyright ©2009 Wolfson Microelectronics plc ...
Page 2
WM8731 / WM8731L 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 – ...
Page 3
WM8731 / WM8731L PIN CONFIGURATION - 28 PIN SSOP 28 1 DBVDD 27 2 CLKOUT 26 3 BCLK 25 4 DACDAT 24 5 DACLRC 23 6 ADCDAT 22 7 ADCLRC 21 8 HPVDD 20 9 LHPOUT 19 10 RHPOUT 18 ...
Page 4
... WM8731 / WM8731L PIN CONFIGURATION – 28 PIN QFN TOP VIEW ORDERING INFORMATION TEMPERATURE DEVICE RANGE o WM8731LSEFL - WM8731LSEFL/R - WM8731SEFL - WM8731SEFL/R -40 to +85 C Note: Reel quantity = 3,500 w AVDD PACKAGE RANGE 28-lead QFN 1.8 to 3.6V (Pb-free) 28-lead QFN 1.8 to 3.6V (Pb-free, tape and reel) 28-lead QFN 2 ...
Page 5
WM8731 / WM8731L PIN DESCRIPTION 28 PIN 28 PIN NAME SSOP QFN 1 5 DBVDD 2 6 CLKOUT 3 7 BCLK 4 8 DACDAT 5 9 DACLRC 6 10 ADCDAT 7 11 ADCLRC 8 12 HPVDD 9 13 LHPOUT 10 ...
Page 6
WM8731 / WM8731L ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under ...
Page 7
WM8731 / WM8731L ELECTRICAL CHARACTERISTICS – WM8731 Test Conditions AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. PARAMETER Digital Logic Levels (CMOS Levels) Input LOW level Input HIGH level ...
Page 8
WM8731 / WM8731L Test Conditions AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. Microphone Input to ADC @ 0dB Gain 48kHz (40kΩ Source Impedance. See Figure 12) ...
Page 9
WM8731 / WM8731L Test Conditions AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. Stereo Headphone Output 0dB Full scale output voltage Max Output Power Signal to Noise Ratio (Note ...
Page 10
WM8731 / WM8731L POWER CONSUMPTION – WM8731 MODE DESCRIPTION Record and Playback Oscillator enabled 0 0 External MCLK 0 0 Oscillator and 0 1 CLKOUT disabled, No microphone Playback Only Oscillator enabled 0 0 External MCLK 0 1 Record Only ...
Page 11
WM8731 / WM8731L ELECTRICAL CHARACTERISTICS – WM8731L Test Conditions AVDD, HPVDD, DBVDD = 1.8V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. PARAMETER Digital Logic Levels (CMOS Levels) Input LOW level Input HIGH level ...
Page 12
WM8731 / WM8731L Test Conditions AVDD, HPVDD, DBVDD = 1.8V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. Microphone Input to ADC @ 0dB Gain 48kHz (40kΩ Source Impedance. See Figure 12) ...
Page 13
WM8731 / WM8731L Test Conditions AVDD, HPVDD, DBVDD = 1.8V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. Stereo Headphone Output 0dB Full scale output voltage Max Output Power Signal to Noise Ratio (Note ...
Page 14
WM8731 / WM8731L POWER CONSUMPTION – WM8731L MODE DESCRIPTION Record and Playback All active, oscillator 0 0 enabled Playback Only Oscillator enabled 0 0 Record Only Line Record oscillator enabled Mic Record oscillator enabled Side Tone ...
Page 15
WM8731 / WM8731L MASTER CLOCK TIMING XTI/MCLK Figure 1 System Clock Timing Requirements Test Conditions AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless otherwise stated. PARAMETER SYMBOL System Clock Timing Information ...
Page 16
WM8731 / WM8731L DIGITAL AUDIO INTERFACE – MASTER MODE WM8731 CODEC Note: ADC and DAC can run at different rates Figure 3 Master Mode Connection BCLK (Output) ADCLRC DAC/LRC (Outputs) ADCDAT DACDAT Figure 4 Digital Audio Data Timing – Master ...
Page 17
WM8731 / WM8731L DIGITAL AUDIO INTERFACE – SLAVE MODE BCLK ADCLRC WM8731 DACLRC CODEC ADCDAT DACDAT Note: The ADC and DAC can run at different rates Figure 5 Slave Mode Connection t BCLK DACLRC/ ADCLRC DACDAT ADCDAT Figure 6 Digital ...
Page 18
WM8731 / WM8731L MPU INTERFACE TIMING CSB SCLK SDIN Figure 7 Program Register Input Timing - 3-Wire MPU Serial Control Mode Test Conditions AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless ...
Page 19
WM8731 / WM8731L t 3 SDIN SCLK t 1 Figure 8 Program Register Input Timing – 2-Wire MPU Serial Control Mode Test Conditions AVDD, HPVDD, DBVDD = 3.3V, AGND = 0V, DCVDD = 1.5V, DGND = 0V, T 256fs unless ...
Page 20
WM8731 / WM8731L DEVICE DESCRIPTION INTRODUCTION The WM8731 low power audio CODEC designed specifically for portable audio products. It’s features, performance and low power consumption make it ideal for portable MP3 players and portable mini-disc players. The CODEC ...
Page 21
WM8731 / WM8731L AVDD VMID AGND MICBIAS RLINEIN Mute Reg 02h RLINEIN VOL MUTE MUTE +12 to -34.5dB, 1.5dB Steps, Reg 02h 0dB/ MICIN 20dB MIC BOOST Reg 08h MUTE LLINEIN VOL MUTE LLINEIN Mute +12 to -34.5dB, 1.5dB Steps, ...
Page 22
WM8731 / WM8731L The gain between the line inputs and the ADC is logarithmically adjustable from +12dB to –34.5dB in 1.5dB steps under software control. The ADC Full Scale input is 1.0V rms at AVDD = 3.3 volts. Any voltage ...
Page 23
WM8731 / WM8731L AGND Figure 11 Line Input Application Drawing For interfacing to a typical CD system recommended that the input is scaled to ensure that there is no clipping of the signal 5.6k ...
Page 24
WM8731 / WM8731L Or alternatively to calculate the value of Rmic to achieve a given gain, G1. The internal 50k and 10k resistors have a tolerance of 15%. For Rmicext = 90k G = 0.5 (-6dB) and for Rmicext = ...
Page 25
WM8731 / WM8731L R1 and R2 form part of the biasing network (refer to Microphone Bias section below). R1 connected to MICBIAS is necessary only for electret type microphones that require a voltage bias. R2 should always be present to ...
Page 26
WM8731 / WM8731L The use of multi-bit feedback and high oversampling rates reduces the effects of jitter and high frequency noise. The ADC Full Scale input is 1.0V rms at AVDD = 3.3 volts. Any voltage greater than full scale ...
Page 27
WM8731 / WM8731L There are several types of ADC filters, frequency and phase responses of these are shown in Digital Filter Characteristics. The filter types are automatically configured depending on the sample rate chosen. Refer to the sample rate section ...
Page 28
WM8731 / WM8731L FROM DAC Figure 18 Multi-Bit Oversampling Sigma Delta Schematic The DAC converts the multi-level digital audio data stream from the DAC digital filters into high quality analogue audio. LINE OUTPUTS The WM8731/L provides two low impedance line ...
Page 29
WM8731 / WM8731L The software control for the line outputs is shown in Table 8. REGISTER ADDRESS 0000100 Analogue Audio Path Control Table 8 Output Software Control The recommended external components are shown in Figure 20. LINEOUT Figure 20 Line ...
Page 30
WM8731 / WM8731L The scheme of the circuit is shown in Figure 21. FROM DAC VIA LINEOUT Figure 21 Headphone Amplifier Schematic LHPOUT and RHPOUT volumes can be independently adjusted under software control using the LHPVOL[6:0] and RHPVOL[6:0] bits respectively ...
Page 31
WM8731 / WM8731L The software control is given in Table 9. REGISTER ADDRESS 0000010 Left Headphone Out 0000011 Right Headphone Out Table 9 Headphone Output Software Control w BIT LABEL DEFAULT 6:0 LHPVOL[6:0] 1111001 ( 0dB ) 7 LZCEN 0 ...
Page 32
WM8731 / WM8731L The recommended external components required to complete the application are shown in Figure 22. HPOUT Figure 22 Headphone Output Application Drawing Recommended values are C1 = 220uF (10V electrolytic 47k C1 forms a DC blocking ...
Page 33
WM8731 / WM8731L The bypass mode is selected under software control using the BYPASS microphone bit as shown in Table 10. In true bypass mode, the output from the DAC (DACSEL) and (SIDETONE) should be de- selected from the line ...
Page 34
WM8731 / WM8731L The side tone mode and attenuation is selected under software control using the SIDETONE bit as shown in Table 11. In true side tone the output from the DAC (DACSEL) and line inputs (BYPASS) should be deselected ...
Page 35
WM8731 / WM8731L CRYSTAL OSCILLATOR The WM8731/L includes a crystal oscillator circuit that allows the audio system’s reference clock to be generated on the device. This is available to the rest of the audio system in buffered form on CLKOUT. ...
Page 36
WM8731 / WM8731L DIGITAL AUDIO INTERFACES WM8731/L may be operated in either one of the 4 offered audio interface modes. These are: • Right justified • Left justified 2 • • DSP mode All four of these modes ...
Page 37
WM8731 / WM8731L LEFT CHANNEL DACLRC/ ADCLRC BCLK 1 BCLK DACDAT ADCDAT MSB 2 Figure Mode Right Justified mode is where the LSB is available on the rising edge of BCLK preceding a DACLRC ...
Page 38
WM8731 / WM8731L Figure 30 DSP/PCM Mode Audio Interface (mode B, LRP=0) In all modes DACLRC and ADCLRC must always change on the falling edge of BCLK, refer to Figure 26, Figure 27, Figure 28, Figure 29 and Figure 30. ...
Page 39
WM8731 / WM8731L ADCDAT lines are always outputs. They power up and return from standby low. DACDAT is always an input expected to be set low by the audio interface controller when the WM8731/L is powered off or ...
Page 40
WM8731 / WM8731L MASTER AND SLAVE MODE OPERATION The WM8731/L can be configured as either a master or slave mode device master mode device the WM8731/L controls sequencing of the data and clocks on the digital audio interface. ...
Page 41
WM8731 / WM8731L AUDIO DATA SAMPLING RATES The WM8731/L provides for two modes of operation (normal and USB) to generate the required DAC and ADC sampling rates. Normal and USB modes are programmed under software control according to the table ...
Page 42
WM8731 / WM8731L SAMPLING RATE ADC kHz 44.1 44.1 8 (Note 1) 8 (Note 1) 88.2 Table 18 Normal Mode Sample Rate Look-up Table Notes not exact, actual = 8.018kHz 2. All ...
Page 43
WM8731 / WM8731L The exact sample rates achieved are defined by the relationships in Table 19 below. TARGET SAMPLING RATE kHz 8 32 44.1 48 88.2 96 Table 19 Normal Mode Actual Sample Rates 128/192fs NORMAL MODE The Normal Mode ...
Page 44
WM8731 / WM8731L USB MODE SAMPLE RATES In USB mode the MCLK/crystal oscillator input is 12MHz only. SAMPLING RATE ADC kHz 48 44.1 (Note 2) 48 44.1 (Note ((Note (Note 88.2 ...
Page 45
WM8731 / WM8731L The exact sample rates supported for all combinations are defined by the relationships in Table 22 below. TARGET SAMPLING RATE kHz 8 32 44.1 48 88.2 96 Table 22 USB Mode Actual Sample Rates ACTIVATING DSP AND ...
Page 46
WM8731 / WM8731L 3-WIRE (SPI COMPATIBLE) SERIAL CONTROL MODE The WM8731/L can be controlled using a 3-wire serial interface. SDIN is used for the program data, SCLK is used to clock in the program data and CSB is use to ...
Page 47
WM8731 / WM8731L Once the WM8731/L has acknowledged a correct address, the controller will send eight data bits (bits B15-B8). WM8731/L will then acknowledge the sent data by pulling SDIN low for one clock pulse. The controller will then send ...
Page 48
WM8731 / WM8731L MICPD: Simultaneously powers down both the Microphone Input and Microphone Bias. If this is done dynamically, audible pops through the ADC will result. This will only be audible if the Microphone Input is selected to the ADC ...
Page 49
WM8731 / WM8731L The device can be powered off by writing to the POWEROFF bit of the Power Down register. In POWEROFF mode the Control Interface and a small portion of the digital remain active. The analogue VMID reference is ...
Page 50
WM8731 / WM8731L REGISTER ADDRESS 0000000 Left Line In 0000001 Right Line In 0000010 Left Headphone Out w BIT LABEL DEFAULT 4:0 LINVOL[4:0] 10111 ( 0dB ) 7 LINMUTE 1 8 LRINBOTH 0 4:0 RINVOL[4:0] 10111 ( 0dB ) 7 ...
Page 51
WM8731 / WM8731L REGISTER ADDRESS 0000011 Right Headphone Out 0000100 Analogue Audio Path Control w BIT LABEL DEFAULT 6:0 RHPVOL 1111001 [6:0] ( 0dB ) 7 RZCEN 0 8 RLHPBOTH 0 0 MICBOOST 0 1 MUTEMIC 1 2 INSEL 0 ...
Page 52
WM8731 / WM8731L REGISTER ADDRESS 0000101 Digital Audio Path Control 0000110 Power Down Control w BIT LABEL DEFAULT 0 ADCHPD 0 2:1 DEEMP[1: DACMU 1 4 HPOR 0 0 LINEINPD 1 1 MICPD 1 2 ADCPD 1 3 ...
Page 53
WM8731 / WM8731L REGISTER ADDRESS 0000111 Digital Audio Interface Format 0001000 Sampling Control w BIT LABEL DEFAULT 1:0 FORMAT[1:0] 10 3:2 IWL[1: LRP 0 5 LRSWAP BCLKINV 0 0 USB/ 0 NORMAL 1 ...
Page 54
WM8731 / WM8731L REGISTER ADDRESS 0001001 Active Control 0001111 Reset Register Table 30 Register Map Description DIGITAL FILTER CHARACTERISTICS The ADC and DAC employ different digital filters. There are 4 types of digital filter, called Type and ...
Page 55
WM8731 / WM8731L DAC FILTERS Mode Group Delay 0 11/FS 1 18/FS 2 5/FS 3 5/FS Table 32 ADC/DAC Digital Filters Group Delay TERMINOLOGY 1. Stop Band Attenuation (dB) - the degree to which the frequency spectrum is attenuated (outside ...
Page 56
WM8731 / WM8731L DAC FILTER RESPONSES 0 -20 -40 -60 -80 -100 0 0.5 1 1.5 Frequency (Fs) Figure 35 DAC Digital Filter Frequency Response –Type 0 0 -20 -40 -60 -80 -100 0 0.5 1 1.5 Frequency (Fs) Figure ...
Page 57
WM8731 / WM8731L 0 -20 -40 -60 -80 -100 0 0.5 1 1.5 Frequency (Fs) Figure 41 DAC Digital Filter Frequency Response –Type 3 ADC FILTER RESPONSES 0 -20 -40 -60 -80 -100 0 0.5 1 1.5 Frequency (Fs) Figure ...
Page 58
WM8731 / WM8731L 0 -20 -40 -60 -80 -100 0 0.5 1 1.5 Frequency (Fs) Figure 47 ADC Digital Filter Frequency Response –Type 2 0 -20 -40 -60 -80 -100 0 0.5 1 1.5 Frequency (Fs) Figure 49 ADC Digital ...
Page 59
WM8731 / WM8731L DIGITAL DE-EMPHASIS CHARACTERISTICS -10 0 2000 4000 6000 8000 Frequency (Fs) Figure 51 De-Emphasis Frequency Response (32kHz -10 0 5000 10000 Frequency (Fs) Figure 53 De-Emphasis Frequency ...
Page 60
WM8731 / WM8731L APPLICATIONS INFORMATION RECOMMENDED EXTERNAL COMPONENTS Figure 57 External Components Diagram w Production Data PD, Rev 4.8, April 2009 60 ...
Page 61
WM8731 / WM8731L MINIMISING POP NOISE AT THE ANALOGUE OUTPUTS To minimise any pop or click noise when the system is powered up or down, the following procedures are recommended. POWER UP SEQUENCE • • • • • POWER DOWN ...
Page 62
WM8731 / WM8731L PACKAGE DIMENSIONS - SSOP DS: 28 PIN SSOP (10.2 x 5.3 x 1.75 mm Dimensions Symbols (mm) MIN NOM A ----- A 0. 1.65 1. 0.22 c ...
Page 63
WM8731 / WM8731L PACKAGE DIMENSIONS - QFN FL: 28 PIN QFN PLASTIC PACKAGE 5 CORNER D2 TIE BAR B D2 EXPOSED 6 GROUND PADDLE ccc B e BOTTOM VIEW ...
Page 64
... WM8731 / WM8731L IMPORTANT NOTICE Wolfson Microelectronics plc (“Wolfson”) products and services are sold subject to Wolfson’s terms and conditions of sale, delivery and payment supplied at the time of order acknowledgement. Wolfson warrants performance of its products to the specifications in effect at the date of shipment. Wolfson reserves the right to make changes to its products and specifications or to discontinue any product or service without notice ...