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DESCRIPTION
The WM8758B is a low power, high quality stereo CODEC
designed for portable applications such as MP3 audio player.
The device integrates preamps for stereo differential mics, and
drivers for headphone and differential or stereo line output.
External component requirements are reduced as no separate
microphone or headphone amplifiers are required. Headphone
and line common feedback improves crosstalk and noise
performance.
Advanced on-chip digital signal processing includes a 5-band
equaliser, a mixed signal Automatic Level Control for the
microphone or line input through the ADC as well as a purely
digital limiter function for record or playback. Additional digital
filtering options are available in the ADC path, to cater for
application filtering such as ‘wind noise reduction’ and notch
filter.
The WM8758B digital audio interface can operate in master or
slave mode with an integrated PLL.
The WM8758B operates at analogue supply voltages from 2.5V
to 3.3V, although the digital supply voltages can operate at
voltages down to 1.71V to save power. Additional power
management control enables individual sections of the chip to
be powered down under software control.
WM8758B
Stereo CODEC with Headphone Driver and Line Out
FEATURES
Stereo CODEC:
DAC SNR 100dB, THD -86dB (‘A’ weighted @ 48kHz)
ADC SNR 92.5dB, THD -75dB (‘A’ weighted @ 48kHz)
Headphone Driver
40mW per channel output power into 16 / 3.3V AVDD2
Line output
Mic Preamps:
Stereo Differential or mono microphone Interfaces
Programmable preamp gain
Psuedo differential inputs with common mode rejection
Programmable ALC / Noise Gate in ADC path
Low-noise bias supplied for electret microphones
Other Features:
Enhanced 3-D function for improved stereo separation
Digital playback limiter
5-band Equaliser (record or playback)
Programmable ADC High Pass Filter (wind noise reduction)
Programmable ADC Notch Filter
PLL supporting various clocks between 8MHz-50MHz
Sample rates supported (kHz): 8, 11.025, 12, 16, 22.05, 24,
32, 44.1, 48
Low power, low voltage
2.5V to 3.6V analogue supplies
1.71V to 3.6V digital supplies
5x5mm 32-lead QFN package
APPLICATIONS
BLOCK DIAGRAM
Portable audio player
WOLFSON MICROELECTRONICS plc
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Production Data, January 2012, Rev 4.4
Copyright
2012
Wolfson Microelectronics plc
WM8758B
TABLE OF CONTENTS
Production Data
DESCRIPTION ....................................................................................................... 1
BLOCK DIAGRAM ................................................................................................ 1
FEATURES ............................................................................................................ 1
APPLICATIONS..................................................................................................... 1
TABLE OF CONTENTS ......................................................................................... 2
PIN CONFIGURATION .......................................................................................... 4
ORDERING INFORMATION .................................................................................. 4
PIN DESCRIPTION ................................................................................................ 5
RECOMMENDED OPERATING CONDITIONS ..................................................... 6
ELECTRICAL CHARACTERISTICS ..................................................................... 7
TERMINOLOGY ............................................................................................................ 12
HEADPHONE OUTPUT PERFORMANCE .......................................................... 13
POWER CONSUMPTION .................................................................................... 14
AUDIO PATHS OVERVIEW ................................................................................ 15
SIGNAL TIMING REQUIREMENTS .................................................................... 16
SYSTEM CLOCK TIMING ............................................................................................. 16
AUDIO INTERFACE TIMING – MASTER MODE .......................................................... 16
AUDIO INTERFACE TIMING – SLAVE MODE ............................................................. 17
CONTROL INTERFACE TIMING – 3-WIRE MODE ...................................................... 18
CONTROL INTERFACE TIMING – 2-WIRE MODE ...................................................... 19
INTERNAL POWER ON RESET CIRCUIT .......................................................... 20
RECOMMENDED POWER UP/DOWN SEQUENCE .................................................... 22
DEVICE DESCRIPTION ...................................................................................... 25
INTRODUCTION ........................................................................................................... 25
INPUT SIGNAL PATH ................................................................................................... 26
ANALOGUE TO DIGITAL CONVERTER (ADC) ........................................................... 33
INPUT LIMITER / AUTOMATIC LEVEL CONTROL (ALC)............................................ 37
OUTPUT SIGNAL PATH ............................................................................................... 42
3D STEREO ENHANCEMENT ...................................................................................... 49
ANALOGUE OUTPUTS ................................................................................................. 49
DIGITAL AUDIO INTERFACES ..................................................................................... 61
AUDIO SAMPLE RATES ............................................................................................... 68
MASTER CLOCK AND PHASE LOCKED LOOP (PLL) ................................................ 68
GENERAL PURPOSE INPUT/OUTPUT........................................................................ 70
OUTPUT SWITCHING (JACK DETECT)....................................................................... 72
CONTROL INTERFACE ................................................................................................ 73
RESETTING THE CHIP ................................................................................................ 74
POWER SUPPLIES....................................................................................................... 75
POWER MANAGEMENT .............................................................................................. 75
POP MINIMISATION ..................................................................................................... 77
REGISTER MAP .................................................................................................. 78
DIGITAL FILTER CHARACTERISTICS .............................................................. 80
TERMINOLOGY ............................................................................................................ 80
DAC FILTER RESPONSES .......................................................................................... 81
ADC FILTER RESPONSES .......................................................................................... 81
HIGHPASS FILTER ....................................................................................................... 82
5-BAND EQUALISER .................................................................................................... 83
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Production Data
WM8758B
APPLICATIONS INFORMATION ........................................................................ 87
RECOMMENDED EXTERNAL COMPONENTS ........................................................... 87
PACKAGE DIAGRAM ......................................................................................... 88
IMPORTANT NOTICE ......................................................................................... 89
ADDRESS: .................................................................................................................... 89
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WM8758B
PIN CONFIGURATION
Production Data
32
31
30
29
28
27
26
25
24
23
22
21
LIP
LIN
L2/GPIO2
RIP
RIN
R2/GPIO3
LRC
BCLK
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
AGND2
ROUT2
OUT3
OUT4
LINE_COM
HP_COM
MODE
SDIN
TOP VIEW
20
19
18
17
ORDERING INFORMATION
ORDER CODE
WM8758CBGEFL/V
WM8758CBGEFL/RV
Note:
Reel quantity = 3,500
TEMPERATURE
RANGE
-40C to +85C
-40C to +85C
PACKAGE
32-lead QFN (5 x 5 mm)
(Pb-free)
32-lead QFN (5 x 5 mm)
(Pb-free, tape and reel)
MOISTURE
SENSITIVITY LEVEL
MSL3
MSL3
PEAK SOLDERING
TEMPERATURE
260 C
260 C
o
o
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Production Data
WM8758B
TYPE
Analogue Input
Analogue Input
Analogue Input
Analogue Input
Analogue Input
Analogue Input
Digital Input / Output
Digital Input / Output
Digital Output
Digital Input
Digital Input
Supply
Supply
Supply
Digital Input / Output
Digital Input
Digital Input / Output
Digital Input
Analogue Input
Analogue Input
Analogue Output
Analogue Output
Analogue Output
Supply
Analogue Output
Supply
Reference
Supply
DESCRIPTION
Left MIC pre-amp positive input
Left MIC pre-amp negative input
Left channel line input/secondary mic pre-amp positive input/GPIO2 pin
Right MIC pre-amp positive input
Right MIC pre-amp negative input
Right channel line input/secondary mic pre-amp positive input/GPIO3 pin
DAC and ADC sample rate clock
Digital audio bit clock
ADC digital audio data output
DAC digital audio data input
Master clock input
Digital ground
Digital core logic supply
Digital buffer (I/O) supply
3-Wire control interface chip select / GPIO1 pin
3-Wire control interface clock input / 2-wire control interface clock input
3-Wire control interface data input / 2-Wire control interface data input
Control interface selection
Headphone ground common feedback input
Line out ground common feedback input
Right line output / mono mix output
Left line output / mono mix output
Line output right 2
Analogue ground (return path for ROUT2/LOUT2)
Line output left 2
Analogue supply (supply for output amplifiers ROUT2/LOUT2)
Decoupling for ADC and DAC reference voltage
Analogue ground (return path for all input amplifiers, PLL, ADC and
DAC, internal bias circuits, output amplifiers LOUT1, ROUT1 and
OUT3/OUT4 on AVDD1 AGND1)
Line or headphone output right 1
Line or headphone output left 1
Analogue supply (feeds all input amplifiers, PLL, ADC and DAC, internal
bias circuits, output amplifiers LOUT1, ROUT1))
Microphone bias
PIN DESCRIPTION
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
NAME
LIP
LIN
L2/GPIO2
RIP
RIN
R2/GPIO3
LRC
BCLK
ADCDAT
DACDAT
MCLK
DGND
DCVDD
DBVDD
CSB/GPIO1
SCLK
SDIN
MODE
HP_COM
LINE_COM
OUT4
OUT3
ROUT2
AGND2
LOUT2
AVDD2
VMID
AGND1
29
30
31
32
ROUT1
LOUT1
AVDD1
MICBIAS
Analogue Output
Analogue Output
Supply
Analogue Output
Note:
It is recommended that the QFN ground paddle should be connected to analogue ground on the application PCB.
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