WM8983 Product Datasheet

WM8983
Mobile Multimedia CODEC with 1W Speaker Driver
DESCRIPTION
FEATURES
The WM8983 is a low power, high quality stereo CODEC
designed for portable multimedia applications. Highly flexible
analogue mixing functions enable new application features,
combining hi-fi quality audio with voice communication.
Stereo CODEC:

DAC SNR 98dB, THD -84dB (‘A’ weighted @ 48kHz)

ADC SNR 95dB, THD -84dB (‘A’ weighted @ 48kHz)

Speaker driver (1W into 8 BTL with 5V supply)
- SNR 90dB
- PSRR 80dB

Headphone driver with ‘capless’ option
- 40mW/channel output power into 16 / 3.3V AVDD2

Pop and click suppression
The device integrates preamps for stereo differential mics,
and includes drivers for speaker, headphone and differential
or stereo line output. External component requirements are
reduced as no separate microphone or headphone amplifiers
are required.
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. A programmable
high pass filter in the ADC path is provided for wind noise
reduction and an IIR with programmable coefficients can be
used as a notch filter to suppress fixed-frequency noise.
The WM8983 digital audio interface can operate in master or
slave mode, while an integrated PLL supports flexible clocking
schemes. A-law and -law companding are fully supported.
The WM8983 operates at analogue supply voltages from 2.5V
to 3.3V, although the digital core can operate at voltages
down to 1.71V to save power. Speaker supplies can operate
up to 5V for increased speaker output power. Additional
power management control enables individual sections of the
chip to be powered down under software control.
Mic Preamps:

Stereo Differential or mono microphone Interfaces

Programmable preamp gain

Pseudo 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

Highly flexible mixing functions

5-band equaliser (ADC or DAC path)

ADC Programmable high pass filter (wind noise reduction)

ADC Programmable IIR notch filter

Aux inputs for stereo analog input signals or ‘beep’

PLL supporting various clocks between 8MHz-50MHz

Sample rates supported (kHz): 8, 11.025, 16, 12, 16, 22.05,
24, 32, 44.1, 48

2.5V to 3.6V analogue supplies

1.71V to 3.6V digital supplies

2.5V to 5.5V speaker supplies

5x5mm 32-lead QFN package
APPLICATIONS

http://www.cirrus.com
Multimedia mobile phones
Copyright  Cirrus Logic, Inc., 2005–2015
(All Rights Reserved)
Rev 4.5
FEB ‘15
2
R2/
GPIO3
RIP
RIN
L2/
GPIO2
LIP
LIN
MICBIAS
Mic
Rbias
NOISY
GND
Mic
Rbias
NOISY
GND
AUXR
AUXL
4k
5k
50k
250k
50k
250k
IP PGA
Gains: -12dB to +35.25dB
IP PGA
Gains: -12dB to +35.25dB
ADCREF,
DACREF
IP BOOST/MIX
IP BOOST/MIX
PLL
R
ADC
L
ADC
GPIO1
Volume
Playback
limiter
3D Enhance
5 Band EQ
A-law and u-law support
I2S / PCM AUDIO
INTERFACE
Programmable
IIR notch filter
Wind noise
filter
ALC / Limiter
3D Enhance
5 Band EQ
Volume
DCVDD
Hi-Fi DAC
DIGITAL
FILTERS
DBVDD
ADC DIGITAL
FILTERS
DGND
RIGHT
OUTPUT
MIXER
WM8983
W
CONTROL
INTERFACE
RDAC
LDAC
LEFT
OUTPUT
MIXER
-1
-1
-1
LOUT2VOL
ROUT1VOL
LOUT1VOL
OUT3 MIXER
AVDD2
+
ROUT2VOL
+
OUT4 MIXER
VMID
AGND2
ROUT2
LOUT2
ROUT1
LOUT1
OUT3
OUT4
Stereo or BTL
speaker output
Stereo headphone
output
Stereo line or
differential output
WM8983
BLOCK DIAGRAM
CSB/GPIO1
SDIN
SCLK
MODE
ADCDAT
LRC
DACDAT
BCLK
MCLK
AVDD1
VMID
AGND1
Rev 4.5
WM8983
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 ..................................................................................................................... 14
TYPICAL PERFORMANCE .......................................................................................... 15
SPEAKER OUTPUT THD VERSUS POWER ......................................................................... 15
TYPICAL POWER CONSUMPTION ...................................................................................... 17
AUDIO PATHS OVERVIEW ......................................................................................... 18
SIGNAL TIMING REQUIREMENTS ............................................................................. 19
SYSTEM CLOCK TIMING ...................................................................................................... 19
AUDIO INTERFACE TIMING – MASTER MODE ................................................................... 19
AUDIO INTERFACE TIMING – SLAVE MODE....................................................................... 20
CONTROL INTERFACE TIMING – 3-WIRE MODE................................................................ 21
CONTROL INTERFACE TIMING – 2-WIRE MODE................................................................ 22
INTERNAL POWER ON RESET CIRCUIT ................................................................... 23
RECOMMENDED CONTROL SEQUENCES ............................................................... 25
POWER UP/DOWN SEQUENCE ........................................................................................... 25
LOUT1/ROUT1 ENABLE SEQUENCE ................................................................................... 28
DEVICE DESCRIPTION ............................................................................................... 29
INTRODUCTION .................................................................................................................... 29
INPUT SIGNAL PATH ............................................................................................................ 31
ANALOGUE TO DIGITAL CONVERTER (ADC) ..................................................................... 40
INPUT LIMITER / AUTOMATIC LEVEL CONTROL (ALC) ..................................................... 44
OUTPUT SIGNAL PATH ........................................................................................................ 57
ANALOGUE OUTPUTS ......................................................................................................... 64
DIGITAL AUDIO INTERFACES .............................................................................................. 82
AUDIO SAMPLE RATES ........................................................................................................ 87
MASTER CLOCK AND PHASE LOCKED LOOP (PLL) .......................................................... 87
COMPANDING....................................................................................................................... 90
GENERAL PURPOSE INPUT/OUTPUT ................................................................................. 92
OUTPUT SWITCHING (JACK DETECT) ................................................................................ 93
CONTROL INTERFACE ......................................................................................................... 94
RESETTING THE CHIP ......................................................................................................... 95
POWER SUPPLIES ............................................................................................................... 95
POWER MANAGEMENT ....................................................................................................... 96
REGISTER MAP ........................................................................................................... 97
REGISTER BITS BY ADDRESS ............................................................................................ 99
DIGITAL FILTER CHARACTERISTICS ..................................................................... 118
TERMINOLOGY ................................................................................................................... 118
DAC FILTER RESPONSES ................................................................................................. 119
Rev 4.5
3
WM8983
ADC FILTER RESPONSES ................................................................................................. 119
HIGHPASS FILTER.............................................................................................................. 120
5-BAND EQUALISER ........................................................................................................... 121
APPLICATIONS INFORMATION ............................................................................... 125
RECOMMENDED EXTERNAL COMPONENTS ................................................................... 125
PACKAGE DIAGRAM ................................................................................................ 126
IMPORTANT NOTICE ................................................................................................ 127
REVISION HISTORY .................................................................................................. 128
4
Rev 4.5
WM8983
MICBIAS
AVDD1
LOUT1
ROUT1
AGND1
VMID
AVDD2
LOUT2
PIN CONFIGURATION
32
31
30
29
28
27
26
25
LIP
1
24
AGND2
LIN
2
23
ROUT2
L2/GPIO2
3
22
OUT3
RIP
4
21
OUT4
RIN
5
20
AUXR
R2/GPIO3
6
19
AUXL
LRC
7
18
MODE
BCLK
8
17
SDIN
12
13
14
15
16
DCVDD
DBVDD
CSB/GPIO1
SCLK
DACDAT
11
DGND
10
MCLK
9
ADCDAT
TOP VIEW
ORDERING INFORMATION
ORDER CODE
TEMPERATURE
RANGE
PACKAGE
MOISTURE
SENSITIVITY LEVEL
PEAK SOLDERING
TEMPERATURE
WM8983GEFL/V
-25C to +85C
32-lead QFN (5 x 5 mm)
(pb-free)
MSL3
260oC
WM8983GEFL/RV
-25C to +85C
32-lead QFN (5 x 5 mm)
(pb-free, tape and reel)
MSL3
260oC
Note:
Reel quantity = 3,500
Rev 4.5
5
WM8983
PIN DESCRIPTION
PIN
NAME
TYPE
1
LIP
Analogue input
Left MIC pre-amp positive input
2
LIN
Analogue input
Left MIC pre-amp negative input
3
L2/GPIO2
Analogue input
Left channel line input/secondary mic pre-amp positive input/GPIO2 pin
RIP
Analogue input
Right MIC pre-amp positive input
4
DESCRIPTION
5
RIN
Analogue input
Right MIC pre-amp negative input
6
R2/GPIO3
Analogue input
Right channel line input/secondary mic pre-amp positive input/GPIO3 pin
7
LRC
Digital Input / Output
DAC and ADC sample rate clock
8
BCLK
Digital Input / Output
Digital audio bit clock
9
ADCDAT
Digital Output
ADC digital audio data output
10
DACDAT
Digital Input
DAC digital audio data input
11
MCLK
Digital Input
Master clock input
12
DGND
Supply
Digital ground
13
DCVDD
Supply
Digital core logic supply
14
DBVDD
Supply
Digital buffer (I/O) supply
15
CSB/GPIO1
Digital Input / Output
16
SCLK
Digital Input
3-Wire control interface clock input / 2-wire control interface clock input
17
SDIN
Digital Input / Output
3-Wire control interface data input / 2-Wire control interface data input
18
MODE
Digital Input
19
AUXL
Analogue input
Left auxiliary input
20
AUXR
Analogue input
Right auxiliary input
21
OUT4
Analogue Output
right line output or mono mix output
22
OUT3
Analogue Output
mono or left line output
23
ROUT2
Analogue Output
Headphone or line output right 2
24
AGND2
Supply
25
LOUT2
Analogue Output
26
AVDD2
Supply
27
VMID
Reference
28
AGND1
Supply
29
ROUT1
Analogue Output
Headphone or line output right 1
30
LOUT1
Analogue Output
Headphone or line output left 1
31
AVDD1
Supply
32
MICBIAS
Analogue Output
3-Wire control interface chip Select / GPIO1 pin
Control interface selection
Analogue ground (feeds ROUT2/LOUT2 and OUT3/OUT4)
Headphone or line output left 2
Analogue supply (feeds output amplifiers ROUT2/LOUT2 and OUT3/OUT4)
Decoupling for ADC and DAC reference voltage
Analogue ground (feeds all input amplifiers, PLL, ADC and DAC, internal
bias circuits, output amplifiers LOUT1, ROUT1)
Analogue supply (feeds all input amplifiers, PLL, ADC and DAC, internal
bias circuits, output amplifiers LOUT1, LOUT2))
Microphone bias
Note:
It is recommended that the QFN ground paddle should be connected to analogue ground on the application PCB.
Refer to the application note WAN_0118 on “Guidelines on How to Use QFN Packages and Create Associated PCB Footprints”
6
Rev 4.5
WM8983
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 Electrical
Characteristics at the test conditions specified.
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible
to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage
of this device.
Cirrus tests its package types according to IPC/JEDEC J-STD-020 for Moisture Sensitivity to determine acceptable storage
conditions prior to surface mount assembly. These levels are:
MSL1 = unlimited floor life at <30C / 85% Relative Humidity. Not normally stored in moisture barrier bag.
MSL2 = out of bag storage for 1 year at <30C / 60% Relative Humidity. Supplied in moisture barrier bag.
MSL3 = out of bag storage for 168 hours at <30C / 60% Relative Humidity. Supplied in moisture barrier bag.
The Moisture Sensitivity Level for each package type is specified in Ordering Information.
CONDITION
DBVDD, DCVDD, AVDD1 supply voltages
AVDD2 supply voltage
MIN
MAX
-0.3V
+4.5V
-0.3V
+7V
Voltage range digital inputs
DGND - 0.3V
DVDD + 0.3V
Voltage range analogue inputs
AGND1 - 0.3V
AGND2 - 0.3V
AVDD1 + 0.3V
AVDD2 + 0.3V
Storage temperature prior to soldering
30C max / 85% RH max
Storage temperature after soldering
-65C
+150C
Notes:
1.
Analogue and digital grounds must always be within 0.3V of each other.
2.
All digital and analogue supplies are completely independent from each other.
3.
Analogue supply voltages should not be less than digital supply voltages.
4.
In non-boosted mode AVDD2 should be  AVDD1. In boost mode, AVDD2 should be  1.5 x AVDD1.
5.
DBVDD must be greater than or equal to DCVDD.
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
Digital supply range (Core)
DCVDD
Digital supply range (Buffer)
DBVDD
Analogue supply range
AVDD1
Speaker supply range
AVDD2
Ground
TEST
CONDITIONS
DGND, AGND1, AGND2
MIN
TYP
MAX
UNIT
1.71
3.6
V
1.712
3.6
V
2.5
3.6
V
2.5
5.5
V
0
V
Notes:
1.
Analogue supply voltages should not be less than digital supply voltages.
2.
DBVDD should be  1.9V when using the PLL.
Rev 4.5
7
WM8983
ELECTRICAL CHARACTERISTICS
Test Conditions
DCVDD=1.8V, AVDD1=AVDD2=DBVDD=3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Microphone Input PGA Inputs (LIP, LIN, RIP, RIN, L2, R2)
INPPGAVOLL, INPPGAVOLR, PGABOOSTL and PGABOOSTR = 0dB
Full-scale Input Signal Level –
Single-ended input via LIN/RIN 1
AVDD/3.3
Vrms
Full-scale Input Signal Level –
Pseudo-differential input 1,2
AVDD*0.7/
3.3
Vrms
INPPGAVOLL/R = +35.25dB
No input signal
22Hz to 20kHz
150
μV
LIN, RIN input resistance
INPPGAVOLL and
INPPGAVOLR = +35.25dB
1.7
k
LIN, RIN input resistance
INPPGAVOLL and
INPPGAVOLR = 0dB
47
k
LIN, RIN input resistance
INPPGAVOLL and
INPPGAVOLR = -12dB
76
k
Input PGA equivalent input noise
LIP, RIP input resistance
All gain settings
95
k
L2, R2 input resistance
L2_2INPPGA and
R2_2INPPGA = 1
L2_2BOOSTVOL and
R2_2BOOSTVOL = 000
90
k
L2, R2 input resistance
L2_2INPPGA and
R2_2INPPGA = 0
L2_2BOOSTVOL and
R2_2BOOSTVOL = +6dB
11
k
L2, R2 input resistance
L2_2INPPGA and
R2_2INPPGA = 0
L2_2BOOSTVOL and
R2_2BOOSTVOL = 0dB
22
k
L2, R2 input resistance
L2_2INPPGA and
R2_2INPPGA = 0
L2_2BOOSTVOL and
R2_2BOOSTVOL = -12dB
60
k
Input Capacitance
10
pF
Gain adjusted by
INPPGAVOLL and
INPPGAVOLL
Programmable Gain Step Size
Guaranteed monotonic
0.75
dB
INPPGAMUTEL and
INPPGAMUTER = 1
100
dB
Input Gain Boost
PGABOOSTL and
PGABOOSTR = 0
0
dB
Input Gain Boost
PGABOOSTL and
PGABOOSTR = 1
+20
dB
Input PGA Mute Attenuation
8
All analogue input pins
Input PGA Programmable Gain
-12
+35.25
dB
Rev 4.5
WM8983
Test Conditions
DCVDD=1.8V, AVDD1=AVDD2=DBVDD=3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Auxiliary Analogue Inputs (AUXL, AUXR)
Full-scale Input Signal Level 2
Left Input boost and mixer
enabled, at +6dB
Left Input boost and mixer
enabled, at 0dB gain
Left Input boost and mixer
enabled, at -12dB gain
Right Input boost, mixer
enabled, at +6dB gain
Right Input boost, mixer
enabled, at 0dB gain
Right Input boost, mixer
enabled, at -12dB gain
All analogue Inputs
Gain adjusted by
AUXL2BOOSTVOL and
AUXR2BOOSTVOL
Input Resistance
Input Capacitance
Gain range from AUXL and AUXR
input to left and right input PGA
mixers
AVDD/3.3
Vrms
4.3
k
8.6
k
39.1
k
3
k
6
k
29
k
10
AUXLBOOSTVOL and
AUXRBOOSTVOL step size
pF
+6
-12
3
dB
dB
L2, R2 Line Input Programmable Gain
Gain adjusted by
L2_2BOOSTVOL and
R2_2BOOSTVOL
Gain range from L2/R2 input to left
and right input PGA mixers
-12
L2/R2_2BOOSTVOL step size
L2/R2_2BOOSTVOL mute
attenuation
+6
dB
3
dB
100
dB
OUT4 to left or right input boost record path
Gain range into left and right input
PGA mixers
Gain adjusted by
OUT4_2ADCVOL
OUT4_2ADCVOL gain step size
OUT4_2ADCVOL mute attenuation
-6
+12
dB
3
dB
100
dB
Analogue to Digital Converter (ADC) - Input from LIN/P and RIN/P in differential configuration to input PGA
INPPGAVOLL, INPPGAVOLR, PGABOOSTL, PGABOOSTR, ADCLVOL and ADCRVOL = 0dB
Signal to Noise Ratio 3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
Channel Separation 6
Rev 4.5
SNR
THD
THD+N
A-weighted
AVDD1=AVDD2=3.3V
93
dB
A-weighted
AVDD1=AVDD2=2.5V
91.5
dB
-12dBV Input
AVDD1=AVDD2=3.3V
-78
dBFS
-12dBV Input
AVDD1=AVDD2=2.5V
-75
dBFS
-12dBV Input
AVDD1=AVDD2=3.3V
-75
dBFS
-12dBV Input
AVDD1=AVDD2=2.5V
-72
dBFS
1kHz full scale input signal
100
dBFS
9
WM8983
Test Conditions
DCVDD=1.8V, AVDD1=AVDD2=DBVDD=3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Analogue to Digital Converter (ADC) - Input from L2, R2 into right PGA mixer. L2_2INPPGA and R2_2INPPGA = 0.
INPPGAVOLL, INPPGAVOLR, L2_2BOOSTVOL, R2_2BOOSTVOL, ADCLVOL and ADCRVOL = 0dB
Signal to Noise Ratio 3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
SNR
THD
THD+N
Channel Separation 6
A-weighted
AVDD1=AVDD2=3.3V
95
dB
A-weighted
AVDD1=AVDD2=2.5V
93
dB
-3dBV Input
AVDD1=AVDD2=3.3V
-86
dBFS
-3dBV Input
AVDD1=AVDD2=2.5V
-78
dBFS
-3dBV Input
AVDD1=AVDD2=3.3V
-80
dBFS
-3dBV Input
AVDD1=AVDD2=2.5V
-76
dBFS
1kHz input signal
100
dBFS
LOUT1VOL and
ROUTVOL = 0dB
AVDD1/3.3
Vrms
A-weighted
AVDD1=AVDD2=3.3V
100
dB
A-weighted
AVDD1=AVDD2=2.5V
99
dB
0dBFS input
AVDD1=AVDD2=3.3V
-84
dBFS
0dBFS input
AVDD1=AVDD2=2.5V
-86
dBFS
0dBFS input
AVDD1=AVDD2=3.3V
-83
dBFS
0dBFS input
AVDD1=AVDD2=2.5V
-84
dBFS
1kHz signal
100
dB
AVDD1/3.3
Vrms
100
dB
A-weighted
AVDD1=AVDD2=2.5V
96
dB
0dBFS input
AVDD1=AVDD2=3.3V
-84
dBFS
0dBFS input
AVDD1=AVDD2=2.5V
-82
dBFS
0dBFS input
AVDD1=AVDD2=3.3V
-82
dBFS
0dBFS input
AVDD1=AVDD2=2.5V
-80
dBFS
1kHz input signal
100
dB
DAC to left and right mixers into 10k / 50pF load on LOUT1 and ROUT1
LOUT1VOL, ROUT1VOL, DACLVOL and DACRVOL = 0dB
Full-scale output 1
Signal to Noise Ratio
3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
SNR
THD
THD+N
Channel Separation 6
DAC to L/R mixer into 10k / 50pF load on L/ROUT2
LOUT2VOL, ROUT2VOL, DACLVOL and DACRVOL = 0dB
Full-scale output 1
Signal to Noise Ratio 3
SNR
A-weighted
AVDD1=AVDD2=3.3V
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
Channel Separation 6
10
THD
THD+N
Rev 4.5
WM8983
Test Conditions
DCVDD=1.8V, AVDD1=AVDD2=DBVDD=3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
DAC to OUT3 and OUT4 mixers to OUT3/OUT4 outputs into 10k / 50pF load. DACLVOL and DACRVOL = 0dB
Full-scale output voltage
AVDD2/3.3
Vrms
Signal to Noise Ratio 3
SNR
A-weighted
AVDD1=AVDD2=3.3V
101.5
dB
Total Harmonic Distortion 4
THD
full-scale signal
AVDD1=AVDD2=3.3V
-80
dBFS
full-scale signal
AVDD1=AVDD2=2.5V
-87
dBFS
full-scale signal
AVDD1=AVDD2=3.3V
-77
dBFS
full-scale signal
AVDD1=AVDD2=2.5V
-85
dBFS
1kHz signal
100
dBFS
Total Harmonic Distortion + Noise 5
THD+N
Channel Separation 6
DAC to left and right mixer into headphone (16Ω load) on LOUT2 and ROUT2
LOUT2VOL, ROUT2VOL, DACLVOL and DACRVOL = 0dB
Full-scale output
AVDD1/3.3
Vrms
Signal to Noise Ratio 3
SNR
A-weighted
AVDD1=AVDD2=3.3V
98
dB
Total Harmonic Distortion 4
THD
Po = 20mW, RL=16Ω
-76
dBFS
THD+N
Po = 20mW, RL=16Ω
-72
dBFS
1kHz signal
100
dB
Total Harmonic Distortion + Noise 5
Channel Separation 6
Bypass paths to left and right output mixers. BYPL2LMIX = 1 and BYPR2RMIX = 1
PGA gain range into mixer
Gain adjusted by
BYPLMIXVOL and
BYPRMIXVOL
-15
BYPLMIXVOL and BYPRMIXVOL
gain step into mixer
Mute attenuation
BYPL2LMIX = 0
BYPR2RMIX = 0
0
+6
dB
3
dB
100
dB
Analogue outputs (LOUT1, ROUT1, LOUT2, ROUT2)
Programmable Gain range
Gain adjusted by
L/ROUT1VOL and
L/ROUT2VOL
-57
0
+6
dB
Programmable Gain step size
Guaranteed monotonic
1
dB
Mute attenuation
1kHz, full scale signal
L/ROUT1MUTE = 1
L/ROUT2MUTE = 1
85
dB
Rev 4.5
11
WM8983
Test Conditions
DCVDD=1.8V, AVDD1=AVDD2=DBVDD=3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
LIN and RIN input PGA to input boost stage into 10k / 50pF load on OUT3/OUT4 outputs
INPPGAVOLL, INPPGAVOLR, PGABOOSTL and PGABOOSTR = 0dB
Full-scale output voltage, 0dB gain
Signal to Noise Ratio 3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
SNR
THD
THD+N
AVDD2/3.3
Vrms
98
dB
A-weighted
AVDD1=AVDD2=2.5V
96
dB
22Hz to 22kHz
AVDD1=AVDD2=3.3V
95.5
dBFS
22Hz to 22kHz
AVDD1=AVDD2=2.5V
93.5
dBFS
full-scale signal
AVDD1=AVDD2=3.3V
-84
dBFS
full-scale signal
AVDD1=AVDD2=2.5V
-82
dBFS
full-scale signal
AVDD1=AVDD2=3.3V
-82
dBFS
full-scale signal
AVDD1=AVDD2=2.5V
-80
dBFS
100
dB
AVDD1/3.3
Vrms
100
dB
A-weighted
AVDD1=AVDD2=2.5V
96
dB
22Hz to 22kHz
AVDD1=AVDD2=3.3V
95.5
dB
22Hz to 22kHz
AVDD1=AVDD2=2.5V
93.5
dB
full-scale signal
AVDD1=AVDD2=3.3V
-87
full-scale signal
AVDD1=AVDD2=2.5V
-69
full-scale signal
AVDD1=AVDD2=3.3V
-85
full-scale signal
AVDD1=AVDD2=2.5V
-68
dBFS
1kHz full scale signal
100
dB
A-weighted
AVDD1=AVDD2=3.3V
90
Channel Separation 6
LIN and RIN into input PGA Bypass to LOUT1 and ROUT1 into 10k / 50pF loads
BYPLMIXVOL, BYPRMIXVOL, LOUT1VOL and ROUT1VOL = 0dB
Full-scale output voltage, 0dB gain
SIGNAL TO NOISE RATIO 3
SNR
A-weighted
90
AVDD1=AVDD2=3.3V
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
Channel separation 6
12
THD
THD+N
-75
dBFS
dBFS
-73
dBFS
Rev 4.5
WM8983
Test Conditions
DCVDD=1.8V, AVDD1=AVDD2=DBVDD=3.3V, TA = +25oC, 1kHz signal, fs = 48kHz, 24-bit audio data unless otherwise stated.
PARAMETER
SYMBOL
TEST CONDITIONS
Speaker Output (LOUT2, ROUT2 with 8 bridge tied load, INVROUT2=1)
Full scale output voltage, 0dB gain. 7
SPKBOOST=0
MIN
Total Harmonic Distortion
Signal to Noise Ratio
Power Supply Rejection Ratio
(50Hz-22kHz)
PO
THD
SNR
PSRR
Microphone Bias
Bias Voltage
MAX
UNIT
AVDD2/
3.3
SPKBOOST=1
Output Power
TYP
Vrms
(AVDD2/
3.3)*1.5
Output power is very closely correlated with THD; see below
PO =200mW, RL = 8,
AVDD2=3.3V
0.04
-68
%
dB
PO =320mW, RL = 8,
AVDD2=3.3V
1.0
-40
%
dB
PO =500mW, RL = 8,
AVDD2=5V
0.02
-74
%
dB
PO =860mW, RL = 8,
AVDD2=5V
1.0
-40
%
dB
AVDD2=3.3V,
RL = 8
90
dB
AVDD2=5V,
RL = 8
90
dB
RL = 8 BTL
80
dB
RL = 8 BTL AVDD2=5V
(boost)
69
dB
MBVSEL=0
0.9 x
AVDD1
V
MBVSEL=1
0.65 x
AVDD1
V
Bias Current Source
for VMICBIAS within +/-3%
Output Noise Voltage
1kHz to 20kHz
3
15
mA
nV/Hz
Digital Input / Output
0.7 
DBVDD
Input HIGH Level
VIH
Input LOW Level
VIL
Output HIGH Level
VOH
IOL=1mA
Output LOW Level
VOL
IOH=1mA
Input Capacitance
Rev 4.5
V
0.3 
DBVDD
All digital pins
0.9 
DBVDD
V
V
0.1 x
DBVDD
10
V
pF
13
WM8983
TERMINOLOGY
1.
Full-scale input and output levels scale in relation to AVDD or AVDD2 depending upon the input or output used. For example,
when AVDD = 3.3V, 0dBFS = 1Vrms (0dBV). When AVDD < 3.3V the absolute level of 0dBFS will decrease with a linear
relationship to AVDD.
2.
3.
Input level to RIP and LIP in differential configurations is limited to a maximum of -3dB or performance will be reduced.
Signal-to-noise ratio (dBFS) – SNR is the difference in level between a reference full scale output signal and the device output
with no signal applied. This ratio is also called idle channel noise. (No Auto-zero or Automute function is employed in achieving
these results).
Total Harmonic Distortion (dBFS) – THD is the difference in level between a reference full scale output signal and the first
seven odd harmonics of the output signal. To calculate the ratio, the fundamental frequency of the output signal is notched out
and an RMS value of the next seven harmonics is calculated.
Total Harmonic Distortion plus Noise (dBFS) – THD+N is the difference in level between a reference full scale output signal
and the sum of the harmonics, wide-band noise and interference on the output signal. To calculate the ratio, the fundamental
frequency of the output signal is notched out and an RMS value of the total harmonics, wide-band noise and interference is
calculated.
Channel Separation (dB) – Also known as Cross-Talk. This is a measure of the amount one channel is isolated from the other.
Normally measured by sending a full scale signal down one channel and measuring the other.
4.
5.
6.
7.
14
The maximum output voltage can be limited by the speaker power supply. If SPKBOOST is set, then AVDD2 should be
1.5xAVDD to prevent clipping taking place in the output stage (when PGA gains are set to 0dB).
Rev 4.5
WM8983
TYPICAL PERFORMANCE
SPEAKER OUTPUT THD VERSUS POWER
Audio Precision
W M8983 THD+N vs. Output Power -- SPKVDD=3.6V
08/29/06 11:40:44
+0T
-10
-20
-30
d
B
r
-40
A
-60
-50
-70
-80
-90
-100
0
50m
100m
150m
200m
250m
300m
350m
400m
450m
500m
550m
600m
W
Sweep
Trace
Color
Line Style
Thick
Data
1
4
7
10
1
1
1
1
Cyan
Green
Red
Blue
Solid
Solid
Solid
Solid
1
1
1
1
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Am pl
Am pl
Am pl
Am pl
Axis
Com m ent
Left
Left
Left
Left
3.6V
3.3V
3V
2.7V
Sys tem AP2
Board Revis ion: 2.0
Device Date Code: 67AALNA
Input Path: SPDIF_IN
Input Signal: 997Hz; Sweep 100% FS -> 0% FS; 24-bit; 256fs (fs =48kHz)
Output Path: R/LOUT2; LOUT2VOL=ROUT2VOL=+6dB; 8ohm BTL
Output Reference: +4.428dBrA
Supplies : External - AVDD=DBVDD=DCVDD=See Com m ent; SPKVDD=+3.6V
BW filter : 22Hz - 22kHz
Additional Filtering: None
Dither: None
RMS or Averaging: Averaging
WM8983_DAC_SPK_THD+N_vs _Power_8ohm _SPKVDD3 6V.at27
Figure 1 Speaker THD+N vs Output Power (Boost Disabled: SPKVDD=3.6V; SPKBOOST=0; AVDD Range =3.6-2.7V)
Audio Precision
W M8983 THD+N vs. Output Power -- SPKVDD=4.2V
08/29/06 12:57:21
+0
T
-10
-20
-30
d
B
r
-40
A
-60
-50
-70
-80
-90
-100
0
50m
100m
150m
200m
250m
300m
350m
400m
450m
500m
550m
600m
650m
700m
750m 800m
W
Sweep
Trace
Color
Line Style
Thick
Data
1
4
7
10
1
1
1
1
Cyan
Red
Green
Blue
Solid
Solid
Solid
Solid
1
1
1
1
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Am pl
Am pl
Am pl
Am pl
Axis
Com m ent
Left
Left
Left
Left
3.6V
3.3V
3V
2.7V
Sys tem AP2
Board Revis ion: 2.0
Device Date Code: 67AALNA
Input Path: SPDIF_IN
Input Signal: 997Hz; Sweep 100%FS -> 0%FS; 24-bit; 256fs (fs =48kHz)
Output Path: R/LOUT2; LOUT2VOL=ROUT2VOL=+6dB; 8ohm BTL
Output Reference: +4.428dBrA
Supplies : External - AVDD=DBVDD=DCVDD=See Com m ent; SPKVDD=+4.2V
BW filter : 22Hz - 22kHz
Additional Filtering: None
Dither: None
RMS or Averaging: Averaging
WM8983_DAC_SPK_THD+N_vs _Power_8ohm _SPKVDD=4.2V.at27
Figure 2 Speaker THD+N vs Output Power (Boost Disabled: SPKVDD=4.2V; SPKBOOST=0; AVDD Range =3.6-2.7V)
Rev 4.5
15
WM8983
Audio Precision
W M8983 THD+N vs. Output Power -- Boost enabled; SPKVDD=4.2V
08/29/06 12:58:55
T
+0
-20
-30
d
B
r
-40
A
-60
-50
-70
-80
-90
-100
0
100m
200m
300m
400m
500m
600m
700m
800m
.9
W
Sweep
Trace
Color
Line Style
Thick
Data
1
4
7
10
1
1
1
1
Cyan
Red
Green
Blue
Solid
Solid
Solid
Solid
1
1
1
1
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Am pl
Am pl
Am pl
Am pl
Axis
Com m ent
Left
Left
Left
Left
3.6V
3.3V
3V
2.7V
Sys tem AP2
Board Revis ion: 2.0
Device Date Code: 67AALNA
Input Path: SPDIF_IN
Input Signal: 997Hz; Sweep 100%FS -> 0%FS; 24-bit; 256fs (fs =48kHz)
Output Path: R/LOUT2; LOUT2VOL=ROUT2VOL=+6dB; 8ohm BTL
Output Reference: +4.428dBrA
Supplies : External - AVDD=DBVDD=DCVDD=See Com m ent; SPKVDD=4.2V
BW filter : 22Hz - 22kHz
Additional Filtering: None
Dither: None
RMS or Averaging: Averaging
WM8983_DAC_SPK_THD+N_vs _Power_8ohm _Boos t_SPKVDD=4.2V.at27
Figure 3 Speaker THD+N vs Output Power (Boost Mode: SPKVDD=4.2V; SPKBOOST=1; AVDD Range =3.6-2.7V)
Audio Precision
W M8983 THD+N vs. Output Power -- Boost enabled; SPKVDD=5V
08/29/06 12:48:45
+0
T
-10
-20
-30
d
B
r
-40
A
-60
-50
-70
-80
-90
-100
0
100m
200m
300m
400m
500m
600m
700m
800m
.9
1
1.1
1.2
W
Sweep
Trace
Color
Line Style
Thick
Data
1
4
7
10
1
1
1
1
Cyan
Red
Green
Blue
Solid
Solid
Solid
Solid
1
1
1
1
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Anlr.THD+N
Am pl
Am pl
Am pl
Am pl
Axis
Com m ent
Left
Left
Left
Left
3.6V
3.3V
3V
2.7V
Sys tem AP2
Board Revis ion: 2.0
Device Date Code: 67AALNA
Input Path: SPDIF_IN
Input Signal: 997Hz; Sweep 100%FS -> 0%FS; 24-bit; 256fs (fs =48kHz)
Output Path: R/LOUT2; LOUT2VOL=ROUT2VOL=+6dB; 8ohm BTL
Output Reference: +4.428dBrA
Supplies : External - AVDD=DBVDD=DCVDD=See Com m ent; SPKVDD=5V
BW filter : 22Hz - 22kHz
Additional Filtering: None
Dither: None
RMS or Averaging: Averaging
WM8983_DAC_SPK_THD+N_vs _Power_8ohm _Boos t_SPKVDD=5V.at27
Figure 4 Speaker THD+N vs Output Power (Boost Mode: SPKVDD=5V; SPKBOOST=1; AVDD Range =3.6-2.7V)
16
Rev 4.5
WM8983
TYPICAL POWER CONSUMPTION
Estimated current consumption for typical scenarios are shown below.
Power delivered to the load is not included.
MODE
TOTAL
mW
IAVDD1 mA
(3.3V)
IAVDD2 mA
(3.3V)
IDCVDD mA
(1.8V)
IDBVDD mA
(1.8V)
Off (No clocks, temperature sensor disabled)
0.010
0.010
0.001
0.002
0.071
Sleep (VREF maintained)
0.100
0.001
0.012
0.003
0.360
Mono Record from Differential MIC (8kHz, PLL enabled)
4.000
0.001
0.400
0.030
13.97
Stereo HP Playback (44.1kHz, PLL enabled)
3.700
0.950
2.100
0.100
19.31
Table 1 Power Consumption
Rev 4.5
17
18
R2
RIP
RIN
AUXR
AUXL
L2
LIP
LIN
OUT4_2LNR
R42[5]
L2_2INPPGA
R44[2]
LIP2INPPGA
R44[0]
VMID
VMID
INPPGAVOLR
R46[5:0]
ALCSEL[0]
R32[7]
INPPGAVOLL
R45[5:0]
ALCSEL[1]
R32[8]
AGND1
R2_2INPPGA
R44[6]
AGND1
+
AVDD1
Differential /
Single-Ended
MIC (Right)
AUXR2BOOSTVOL
R48[2:0] (Mute=000)
INPPGAMUTER
R46[6]
RIP2INPPGA
R44[4]
from
ALC
PGABOOSTR
R48[8]
R2_2BOOSTVOL
R48[6:4] (Mute=000)
L2_2BOOSTVOL
R47[6:4] (Mute=000)
from
ALC
PGABOOSTL
R47[8]
INPPGAMUTEL
R45[6]
AUXL2BOOSTVOL
R47[2:0] (Mute=000)
VMID
VMID
+
AVDD1 Differential /
Single-Ended
MIC (Lett)
OUT4_2ADCVOL
R42[8:6] (Mute=000)
AGND1
+
MODE
AVDD1
AGND1
+
AVDD1
Right
PGA
Mixer
Left
PGA
Mixer
VREF-
AGND1
VREF-
DCVDD
DGND
PLL
AGND1
DCVDD
DGND
Notch
Filter
EQ/
3D
DBVDD
VREF+
DACDAT
DGND
AVDD1
AGND1
VREF-
DGND
ADCDAT
AGND1
VREF-
R DAC
DCVDD
DGND
EQ3DMODE
R18[8]
EQ can be applied to
ADC or DAC, but not
both simultaneously
EQ/
3D
DACPOLR
R10[1]
DACPOLL
R10[0]
VREF+
AVDD1
L DAC
DCVDD
Digital Audio Interface
DGND
ADCRPOL
R14[1]
Limiter
Digital Core
ADCLPOL
R14[0]
DCVDD
ALC/
Limiter
HPF
DGND
R ADC
VREF+
AVDD1
AGND1
BYPRMIXVOL
R51[4:2]
AVDD1
DCVDD
L ADC
VREF+
AVDD1
BYPLMIXVOL
R50[4:2]
WM8983 Audio Signal Paths
AUXL2LMIX
R50[5]
AUXRMIXVOL
R51[8:6]
AUXR2RMIX
R51[5]
BYPR2RMIX
R51[1]
DACR2RMIX
R51[0]
DACL2RMIX
R49[6]
DACR2LMIX
R49[5]
DACL2LMIX
R50[0]
BYPL2LMIX
R50[1]
AUXLMIXVOL
R50[8:6]
Right
Mixer
AGND1
+
AVDD1
Left
Mixer
AGND1
+
AVDD1
VMID
ROUT2MUTE
R55[6]
BYPL2RMIX
R43[8]
VMID
AGND2
AVDD1
-1
ROUT1
LOUT1
OUT3
OUT4
INVROUT2
R43[4]
AGND2
ROUT2
LOUT2
AVDD2 LOUT2VOL
R54[5:0]
ROUT1VOL AGND1
R53[5:0]
AVDD2 ROUT2VOL
R55[5:0]
VMID
AVDD1
AGND1
AVDD1
AGND1
AVDD1
LOUT1VOL AGND1
R52[5:0]
LOUT2MUTE
R54[6]
VMID
ROUT1MUTE
R53[6]
VMID
LOUT1MUTE
R52[6]
OUT3
Mixer
LMIX2OUT3
R56[1]
BYPR2LMIX
R43[7]
VMID
OUT4MUTE
R57[6]
OUT3MUTE
R56[6]
AGND1
+
AVDD1
AGND1
+
AVDD1
OUT4
Mixer
LDAC2OUT3
R56[0]
BYPL2OUT3
R56[2]
OUT4_2OUT3
R56[3]
BYPR2OUT4
R57[2]
RMIX2OUT4
R57[1]
LMIX2OUT4
R57[4]
LDAC2OUT4
R57[3]
RDAC2OUT4
R57[0]
OUT3_2OUT4
R57[7]
WM8983
AUDIO PATHS OVERVIEW
Rev 4.5
WM8983
SIGNAL TIMING REQUIREMENTS
SYSTEM CLOCK TIMING
tMCLKL
MCLK
tMCLKH
tMCLKY
Figure 5 System Clock Timing Requirements
Test Conditions
DCVDD=1.8V, DBVDD=AVDD1=AVDD2=3.3V, DGND=AGND1=AGND2=0V, TA = +25oC, Slave Mode
PARAMETER
SYMBOL
CONDITIONS
MIN
TMCLKY
MCLK=SYSCLK (=256fs)
81.38
MCLK input to PLL Note 1
20
TYP
MAX
UNIT
System Clock Timing Information
MCLK cycle time
MCLK duty cycle
TMCLKDS
ns
ns
60:40
40:60
Note:
1. PLL pre-scaling and PLL N and K values should be set appropriately so that SYSCLK is no greater than 12.288MHz.
AUDIO INTERFACE TIMING – MASTER MODE
BCLK
(Output)
tDL
LRC
(Output)
tDDA
ADCDAT
DACDAT
tDST
tDHT
Figure 6 Digital Audio Data Timing – Master Mode (see Control Interface)
Test Conditions
DCVDD=1.8V, DBVDD=AVDD1=AVDD2=3.3V, DGND=AGND1=AGND2=0V, TA=+25oC, Master Mode, fs=48kHz,
MCLK=256fs, 24-bit data, unless otherwise stated.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
10
ns
25
ns
Audio Data Input Timing Information
LRC propagation delay from BCLK falling edge
tDL
ADCDAT propagation delay from BCLK falling edge
tDDA
DACDAT setup time to BCLK rising edge
tDST
10
ns
DACDAT hold time from BCLK rising edge
tDHT
10
ns
Rev 4.5
19
WM8983
AUDIO INTERFACE TIMING – SLAVE MODE
tBCH
tBCL
BCLK
tBCY
LRC
tDS
tLRSU
tLRH
DACDAT
tDD
tDH
ADCDAT
Figure 7 Digital Audio Data Timing – Slave Mode
Test Conditions
DCVDD=1.8V, DBVDD=AVDD1=AVDD2=3.3V, DGND=AGND1=AGND2=0V, TA=+25oC, Slave Mode, fs=48kHz,
MCLK= 256fs, 24-bit data, unless otherwise stated.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
BCLK cycle time
tBCY
50
ns
BCLK pulse width high
tBCH
20
ns
BCLK pulse width low
tBCL
20
ns
LRC set-up time to BCLK rising edge
tLRSU
10
ns
LRC hold time from BCLK rising edge
tLRH
10
ns
DACDAT hold time from BCLK rising edge
tDH
10
ns
DACDAT set-up time to BCLK rising edge
tDS
10
ns
ADCDAT propagation delay from BCLK falling edge
tDD
Audio Data Input Timing Information
25
ns
Note:
BCLK period should always be greater than or equal to MCLK period.
20
Rev 4.5
WM8983
CONTROL INTERFACE TIMING – 3-WIRE MODE
3-wire mode is selected by connecting the MODE pin high.
tCSL
tCSH
CSB/GPIO
tCSS
tSCY
tSCH
tSCS
tSCL
SCLK
LSB
SDIN
tDSU
tDHO
Figure 8 Control Interface Timing – 3-Wire Serial Control Mode
Test Conditions
DCVDD=1.8V, DBVDD=AVDD1=AVDD2=3.3V, DGND=AGND1=AGND2=0V, TA=+25oC, Slave Mode, fs=48kHz,
MCLK=256fs, 24-bit data, unless otherwise stated.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
Program Register Input Information
SCLK rising edge to CSB rising edge
tSCS
80
ns
SCLK pulse cycle time
tSCY
200
ns
SCLK pulse width low
tSCL
80
ns
SCLK pulse width high
tSCH
80
ns
SDIN to SCLK set-up time
tDSU
40
ns
SCLK to SDIN hold time
tDHO
40
ns
CSB pulse width low
tCSL
40
ns
CSB pulse width high
tCSH
40
ns
CSB rising to SCLK rising
tCSS
40
Pulse width of spikes that will be suppressed
tps
0
Rev 4.5
ns
5
ns
21
WM8983
CONTROL INTERFACE TIMING – 2-WIRE MODE
2-wire mode is selected by connecting the MODE pin low.
t3
t3
t5
SDIN
t4
t6
t2
t8
SCLK
t1
t9
t7
Figure 9 Control Interface Timing – 2-Wire Serial Control Mode
Test Conditions
DCVDD=1.8V, DBVDD=AVDD1=AVDD2=3.3V, DGND=AGND1=AGND2=0V, TA=+25oC, Slave Mode, fs=48kHz,
MCLK=256fs, 24-bit data, unless otherwise stated.
PARAMETER
SYMBOL
MIN
TYP
MAX
UNIT
SCLK Low Pulse-Width
t1
1.3
526
kHz
us
SCLK High Pulse-Width
t2
600
ns
Hold Time (Start Condition)
t3
600
ns
Setup Time (Start Condition)
t4
600
ns
Data Setup Time
t5
100
ns
SDIN, SCLK Rise Time
t6
300
ns
SDIN, SCLK Fall Time
t7
300
ns
Setup Time (Stop Condition)
t8
Data Hold Time
t9
Pulse width of spikes that will be suppressed
tps
Program Register Input Information
SCLK Frequency
22
0
600
0
ns
900
ns
5
ns
Rev 4.5
WM8983
INTERNAL POWER ON RESET CIRCUIT
AVDD1
VDD
INTERNAL PORB
DCVDD
T
Power On Reset
Circuit
GND
AGND1
Figure 10 Internal Power on Reset Circuit Schematic
The WM8983 includes an internal Power-On-Reset Circuit, as shown in Figure 10, which is used reset
the digital logic into a default state after power up. The POR circuit is powered from AVDD1 and
monitors DCVDD. It asserts PORB low if AVDD1 or DCVDD is below a minimum threshold.
DCVDD
Vpord_on
DGND
AVDD1
Vpora
Vpora_off
AGND1
HI
INTERNAL PORB
LO
No Power
POR
Undefined
Internal
POR active
Device Ready
Internal POR active
Figure 11 Typical Power up Sequence where AVDD1 is powered before DCVDD
Figure 11 shows a typical power-up sequence where AVDD1 comes up first. When AVDD1 goes
above the minimum threshold, Vpora, there is enough voltage for the circuit to guarantee PORB is
asserted low and the chip is held in reset. In this condition, all writes to the control interface are
ignored. Now AVDD1 is at full supply level. Next DCVDD rises to V pord_on and PORB is released high
and all registers are in their default state and writes to the control interface may take place.
On power down, where AVDD1 falls first, PORB is asserted low whenever AVDD1 drops below the
minimum threshold Vpora_off.
Rev 4.5
23
WM8983
DCVDD
Vpord_off
DGND
AVDD1
Vpora_on
Vpora
AGND1
HI
INTERNAL PORB
LO
No Power
POR
Undefined
Internal
POR active
Device Ready
Internal POR active
Figure 12 Typical Power up Sequence where DCVDD is Powered before AVDD1
Figure 12 shows a typical power-up sequence where DCVDD comes up first. First it is assumed that
DCVDD is already up to specified operating voltage. When AVDD1 goes above the minimum
threshold, Vpora, there is enough voltage for the circuit to guarantee PORB is asserted low and the chip
is held in reset. In this condition, all writes to the control interface are ignored. When AVDD1 rises to
Vpora_on, PORB is released high and all registers are in their default state and writes to the control
interface may take place.
On power down, where DCVDD falls first, PORB is asserted low whenever DCVDD drops below the
minimum threshold Vpord_off.
SYMBOL
MIN
TYP
MAX
UNIT
Vpora
0.4
0.6
0.8
V
Vpora_on
0.9
1.2
1.6
V
Vpora_off
0.4
0.6
0.8
V
Vpord_on
0.5
0.7
0.9
V
Vpord_off
0.4
0.6
0.8
V
Table 2 Typical POR Operation (Typical Simulated Values)
Notes:
24
1.
If AVDD1 and DCVDD suffer a brown-out (i.e. drop below the minimum recommended operating
level but do not go below Vpora_off or Vpord_off), then the chip will not reset and will resume normal
operation when the voltage is back to the recommended level again.
2.
The chip will enter reset at power down when AVDD1 or DCVDD falls below V pora_off or Vpord_off.
This may be important if the supply is turned on and off frequently by a power management
system.
3.
The minimum tpor period is maintained even if DCVDD and AVDD1 have zero rise time. This
specification is guaranteed by design rather than test.
Rev 4.5
WM8983
RECOMMENDED CONTROL SEQUENCES
POWER UP/DOWN SEQUENCE
In order to minimise output pop and click noise, it is recommended that the WM8983 device is
powered up and down under control using the following sequences:
Power Up:

Turn on external power supplies. Wait for supply voltage to settle.

Set low bias mode, BIASCUT = 1.

Mute all Outputs and set PGAs to minimum gain, R52 to R57 = 0x140h.

Enable VMID independent current bias, POBCTRL = 1, DELEN = 1.

Enable required outputs, DACs and mixers.

Enable analogue bias, BIASEN, and VMID with required charge time e.g. VMIDSEL=01 =
100kΩ.

Setup digital interface, input amplifiers, PLL, ADCs and DACs for desired operation.

Unmute L/ROUT1 and set desired volume, e.g. for 0dB R52 and R53 = 0x139h.

Unmute L/ROUT2 and set desired volume, e.g. for 0dB R54 and R55 = 0x139h.

Disable VMID independent current bias, POBCTRL = 0, DELEN = 0.
Power Down:

Disable Thermal shutdown

Disable VMIDSEL=00 and BIASEN=0

Wait for VMID to discharge

Power off registers R1, R2, R3 = 0x000h

Remove external power supplies
Note:
Charging time constant is determined by impedance selected by VMIDSEL and the value of
decoupling capacitor connected to VMID pin.
Rev 4.5
25
WM8983
Vpor_on
Vpora
Vpor_off
Power Supply
DGND
POR
Device Ready
No Power
POR Undefined
Internal POR active
POR
DNC
I2S Clocks
DNC
tadcint
ADC Internal
State
Power down
Init
tadcint
Normal Operation
PD
Init
Normal Operation
Power down
tmidrail_on
tmidrail_off
(Note 1)
Analogue Inputs
(Note 2)
AVDD/2
GD
GD
GD
GD
ADCDAT pin
(Note 3)
ADCEN bit
ADC enabled
INPPGAEN bit
VMIDSEL/
BIASEN bits
ADC off
ADC enabled
INPPGA enabled
(Note 4)
VMID enabled
Figure 13 ADC Power Up and Down Sequence (not to scale)
SYMBOL
MIN
TYPICAL
MAX
UNIT
tmidrail_on
300
ms
tmidrail_off
>6
s
tadcint
2/fs
s
ADC Group Delay
29/fs
s
Table 3 Typical POR Operation (typical simulated values)
Notes:
26
1.
The analogue input pin charge time, tmidrail_on, is determined by the VMID pin charge time. This
time is dependent upon the value of VMID decoupling capacitor and VMID pin input resistance
and AVDD power supply rise time.
2.
The analogue input pin discharge time, tmidrail_off, is determined by the analogue input coupling
capacitor discharge time. The time, tmidrail_off, is measured using a 1μF capacitor on the analogue
input but will vary dependent upon the value of input coupling capacitor.
3.
While the ADC is enabled, there will be LSB data bit activity on the ADCDAT pin due to system
noise, but no significant digital output will be present.
4.
The VMIDSEL and BIASEN bits must be set to enable analogue input midrail voltage and for
normal ADC operation.
5.
ADCDAT data output delay from power up – with power supplies starting from 0V – is
determined primarily by the VMID charge time. ADC initialisation and power management bits
may be set immediately after POR is released; VMID charge time will be significantly longer and
will dictate when the device is stabilised for analogue input.
6.
ADCDAT data output delay at power up from device standby (power supplies already applied) is
determined by ADC initialisation time, 2/fs.
Rev 4.5
WM8983
Vpor_on
Vpora
Power Supply
Vpor_off
DGND
POR
Device Ready
No Power
POR Undefined
Internal POR active
tpor
DNC
I2S Clocks
DNC
tdacint
DAC Internal State
Power down
Init
tdacint
Normal Operation
PD
Init
Normal Operation
tline_midrail_on
tline_midrail_off
(Note 1)
Line Out Outputs
Power down
(Note 3)
AVDD/2
(Note 2)
thp_midrail_on
thp_midrail_off
(Note 4)
(Note 5)
AVDD/2
HP Outputs
GD
GD
GD
DACDAT pin
DACEN bit
DAC enabled
DAC disabled
Analogue outputs
enable bits
VMIDSEL/
BIASEN bits
DAC enabled
DAC off
DAC disabled
Analogue outputs enabled
(Note 6)
VMID enabled
Figure 14 DAC Power Up and Down Sequence (not to scale)
SYMBOL
MIN
TYPICAL
MAX
UNIT
tline_midrail_on
300
tline_midrail_off
>6
ms
s
thp_midrail_on
300
ms
thp__midrail_off
>6
s
tdacint
2/fs
s
DAC Group Delay
29/fs
s
Table 4 Typical POR Operation (typical simulated values)
Notes:
Rev 4.5
1.
The lineout charge time, tline_midrail_on, is determined by the VMID pin charge time. This time is
dependent upon the value of VMID decoupling capacitor and VMID pin input resistance and
AVDD power supply rise time. The values above were measured using a 4.7μF capacitor.
2.
It is not advisable to allow DACDAT data input during initialisation of the DAC. If the DAC data
value is not zero at point of initialisation, then this is likely to cause a pop noise on the analogue
outputs. The same is also true if the DACDAT is removed at a non-zero value, and no mute
function has been applied to the signal beforehand.
3.
The lineout discharge time, tline_midrail_off, is determined by the VMID pin discharge time. This time
is dependent upon the value of VMID decoupling capacitor and VMID pin input resistance. The
values above were measured using a 4.7μF capacitor.
4.
The headphone charge time, thp_midrail_on, is dependent upon the value of VMID decoupling
capacitor and VMID pin input resistance and AVDD power supply rise time. The values above
were measured using a 4.7μF VMID decoupling capacitor.
5.
The headphone discharge time, thp_midrail_off, is dependent upon the value of VMID decoupling
capacitor and VMID pin input resistance. The values above were measured using a 4.7μF VMID
decoupling capacitor.
6.
The VMIDSEL and BIASEN bits must be set to enable analogue output midrail voltage and for
normal DAC operation.
27
WM8983
LOUT1/ROUT1 ENABLE SEQUENCE
In order to minimise click noise, it is recommended that the WM8983 headphone outputs are enabled
using the following sequence:

Activate dual enable function DELEN = 1 (R42).

Enable L/ROUT1 amplifier core, LOUT1EN = 1, ROUT1EN = 1 (R2).

Enable output FETs, OUT1DEL = 1 (R42).

Disable DELEN = 0.

Reset OUT1DEL = 0.
Notes:
All outputs on WM8983 can also be enabled with a single write to enable bits in registers 2 and 3
without click minimisation. Disabling outputs does not require click minimisation.
28
Rev 4.5
WM8983
DEVICE DESCRIPTION
INTRODUCTION
The WM8983 is a low power audio CODEC combining a high quality stereo audio DAC and ADC, with
flexible line and microphone input and output processing.
FEATURES
The chip offers great flexibility in use, and so can support many different modes of operation as
follows:
MICROPHONE INPUTS
Two pairs of stereo microphone inputs are provided, allowing a pair of stereo microphones to be
pseudo-differentially connected, with user defined gain. The provision of the common mode input pin
for each stereo input allows for rejection of common mode noise on the microphone inputs (level
depends on gain setting chosen). A microphone bias is output from the chip which can be used to
bias both microphones. The signal routing can be configured to allow manual adjustment of mic
levels, or to allow the ALC loop to control the level of mic signal that is transmitted.
Total gain through the microphone paths of up to +55.25dB can be selected.
PGA AND ALC OPERATION
A programmable gain amplifier is provided in the input path to the ADC. This may be used manually
or in conjunction with a mixed analogue/digital automatic level control (ALC) which keeps the
recording volume constant.
LINE INPUTS (AUXL, AUXR)
AUXL and AUXR, can be used as a stereo line input or as an input for warning tones (or ‘beeps’) etc.
These inputs can be summed into the record paths, along with the microphone preamp outputs, so
allowing for mixing of audio with ‘backing music’ etc as required.
ADC
The stereo ADC uses a 24-bit high-order oversampling architecture to deliver optimum performance
with low power consumption.
HI-FI DAC
The hi-fi DAC provides high quality audio playback suitable for all portable audio hi-fi type
applications, including MP3 players, portable multimedia devices and portable disc players of all
types.
OUTPUT MIXERS
Flexible mixing is provided on the outputs of the device. A stereo mixer is provided for the stereo
headphone or line outputs, LOUT1/ROUT1, and additional summers on the OUT3/OUT4 outputs
allow for an optional differential or stereo line output on these pins. Gain adjustment PGAs are
provided for the LOUT1/ROUT1 and LOUT2/ROUT2 outputs, and signal switching is provided to allow
for all possible signal combinations.
OUT3 and OUT4 can be configured to provide an additional stereo or mono differential lineout from
the output of the DACs, the mixers or the input microphone boost stages. They can also provide a
midrail reference for pseudo differential inputs to external amplifiers.
Rev 4.5
29
WM8983
AUDIO INTERFACES
The WM8983 has a standard audio interface to support the transmission of stereo data to and from
the chip. This interface is a 3 wire standard audio interface which supports a number of audio data
formats including:

I2S

DSP/PCM Mode (a burst mode in which LRC sync plus 2 data packed words are
transmitted)

MSB-First, left justified

MSB-First, right justified
The interface can operate in master or slave modes.
CONTROL INTERFACES
To allow full software control over all features, the WM8983 offers a choice of 2 or 3 wire control
interface. It is fully compatible and an ideal partner for a wide range of industry standard
microprocessors, controllers and DSPs.
Selection of the mode is via the MODE pin. In 2 wire mode, the address of the device is fixed as
0011010.
CLOCKING SCHEMES
WM8983 offers the normal audio DAC clocking scheme operation, where 256fs MCLK is provided to
the DAC and ADC.
A PLL is included which may be used to generate these clocks in the event that they are not available
from the system controller. This PLL can accept a range of common input clock frequencies between
8MHz and 50MHz to generate high quality audio clocks. If this PLL is not required for generation of
these clocks, it can be reconfigured to generate alternative clocks which may then be output on the
GPIO pins and used elsewhere in the system.
POWER CONTROL
The design of the WM8983 has given much attention to power consumption without compromising
performance. It operates at very low voltages, includes the ability to power off any unused parts of the
circuitry under software control, and includes standby and power off modes.
AUXILIARY ANALOG INPUT SUPPORT
Additional stereo analog signals might be connected to the Line inputs of WM8983 (e.g. melody chip
or FM radio), and the stereo signal listened to via headphones, or recorded, simultaneously if
required.
30
Rev 4.5
WM8983
INPUT SIGNAL PATH
The WM8983 has a number of flexible analogue inputs. There are two input channels, Left and Right,
each of which consists of an input PGA stage followed by a boost/mix stage which drives into the hi-fi
ADC. Each input path has three input pins which can be configured in a variety of ways to
accommodate single-ended, differential or dual differential microphones. There are two auxiliary input
pins which can be fed into to the input boost/mix stage as well as driving into the output path. A
bypass path exists from the output of the boost/mix stage into the output left/right mixers.
MICROPHONE INPUTS
The WM8983 can accommodate a variety of microphone configurations including single ended and
pseudo differential inputs. The inputs to the left pseudo differential input PGA are LIP and L2. The
inputs to the right pseudo differential input PGA are RIP and R2. LIN and RIN are used for a.c.
coupled ground inputs.
In single-ended microphone input configuration, the microphone signal should be input to LIN or RIN
and the non-inverting input of the input PGA clamped to VMID.
INPPGAVOLL,
R45[5:0]
LIN
LIN2INPPGA,
R44[1]
65k
-12dB to +35.25dB
LIP2INPPGA,
R44[0]
LIP
65k
L2
65k
To input
BOOST/mix
stage
L2_2INPPGA,
R44[2]
VMID
VMID
LIP2INPPGA
INPPGAVOLR,
R46[5:0]
RIN
L2_2INPPGA
RIN2INPPGA,
R44[5]
65k
-12dB to +35.25dB
RIP2INPPGA,
R44[4]
RIP
65k
R2
65k
To input
BOOST/mix
stage
R2_2INPPGA,
R44[6]
VMID
VMID
RIP2INPPGA
R2_2INPPGA
Figure 15 Microphone Input PGA Circuit
Rev 4.5
31
WM8983
The input PGAs are enabled by the INPPGAENL and INPPGAENR register bits.
REGISTER
ADDRESS
BIT
R2
Power
Management
2
LABEL
DEFAULT
DESCRIPTION
2
INPPGAENL
0
Left channel input PGA enable
0 = disabled
1 = enabled
3
INPPGAENR
0
Right channel input PGA enable
0 = disabled
1 = enabled
Table 5 Input PGA Enable Register Settings
REGISTER
ADDRESS
BIT
R44
Input
Control
0
LABEL
LIP2INPPGA
DEFAULT
1
DESCRIPTION
Connect LIP pin to left channel input PGA
amplifier positive terminal.
0 = LIP not connected to input PGA
1 = input PGA amplifier positive terminal
connected to LIP (constant input
impedance)
1
LIN2INPPGA
1
Connect LIN pin to left channel input PGA
negative terminal.
0 = LIN not connected to input PGA
1 = LIN connected to input PGA amplifier
negative terminal.
2
L2_2INPPGA
0
Connect L2 pin to left channel input PGA
positive terminal.
0 = L2 not connected to input PGA
1 = L2 connected to input PGA amplifier
positive terminal (constant input
impedance).
4
RIP2INPPGA
1
Connect RIP pin to right channel input
PGA amplifier positive terminal.
0 = RIP not connected to input PGA
1 = right channel input PGA amplifier
positive terminal connected to RIP
(constant input impedance)
5
RIN2INPPGA
1
Connect RIN pin to right channel input
PGA negative terminal.
0 = RIN not connected to input PGA
1 = RIN connected to right channel input
PGA amplifier negative terminal.
6
R2_2INPPGA
0
Connect R2 pin to right channel input PGA
positive terminal.
0 = R2 not connected to input PGA
1 = R2 connected to input PGA amplifier
positive terminal (constant input
impedance).
Table 6 Input PGA Control
INPUT PGA VOLUME CONTROLS
The input microphone PGAs have a gain range from -12dB to +35.25dB in 0.75dB steps. The gain
from the LIN/RIN input to the PGA output and from the L2/R2 amplifier to the PGA output are always
common and controlled by the register bits INPPGAVOLL/R[5:0]. These register bits also affect the
LIP pin when LIP2INPPGA=1, the L2 pin when L2_2INPPGA=1, the RIP pin when RIP2INPPGA=1
and the L2 pin when L2_2INPPGA=1.
When the Automatic Level Control (ALC) is enabled the input PGA gains are controlled automatically
32
Rev 4.5
WM8983
and the INPPGAVOLL/R bits should not be used.
REGISTER
ADDRESS
BIT
R45
Left channel
input PGA
volume
control
5:0
INPPGAVOLL
010000
Left channel input PGA volume
000000 = -12dB
000001 = -11.25dB
.
010000 = 0dB
.
111111 = +35.25dB
6
INPPGAMUTEL
0
Mute control for left channel input PGA:
0 = Input PGA not muted, normal
operation
1 = Input PGA muted (and disconnected
from the following input BOOST stage).
7
INPPGAZCL
0
Left channel input PGA zero cross
enable:
0 = Update gain when gain register
changes
1 = Update gain on 1st zero cross after
gain register write.
8
INPPGAVU
Not
latched
INPPGA left and INPPGA right volume
do not update until a 1 is written to
INPPGAVU (in reg 45 or 46)
5:0
INPPGAVOLR
010000
Right channel input PGA volume
000000 = -12dB
000001 = -11.25db
.
010000 = 0dB
.
111111 = +35.25dB
6
INPPGAMUTER
0
Mute control for right channel input PGA:
0 = Input PGA not muted, normal
operation
1 = Input PGA muted (and disconnected
from the following input BOOST stage).
7
INPPGAZCR
0
Right channel input PGA zero cross
enable:
0 = Update gain when gain register
changes
1 = Update gain on 1st zero cross after
gain register write.
8
INPPGAVU
Not
latched
INPPGA left and INPPGA right volume
do not update until a 1 is written to
INPPGAVU (in reg 45 or 46)
8:7
ALCSEL
00
LABEL
DEFAULT
DESCRIPTION
(See “Volume Updates” below)
R46
Right
channel
input PGA
volume
control
(See “Volume Updates” below)
R32
ALC control
1
ALC function select:
00 = ALC disabled
01 = Right channel ALC enabled
10 = Left channel ALC enabled
11 = Both channels ALC enabled
Table 7 Input PGA Volume Control
Rev 4.5
33
WM8983
VOLUME UPDATES
Volume settings will not be applied to the PGAs until a ‘1’ is written to one of the INPPGAVU bits. This
is to allow left and right channels to be updated at the same time, as shown in Figure 16.
0dB Gain
6dB Gain
Left PGA Input
Left PGA Output
Left and right channels
updated at same time
Right PGA Input
Right PGA Output
Control Interface
Write
010100
to
R45[5:0]
Write
010100
to
R46[5:0]
R45[8]=0
R46[8]=1
Time
Write Left PGA Volume
without update
Write Right PGA Volume
with update
Figure 16 Simultaneous Left and Right Volume Updates
If the volume is adjusted while the signal is a non-zero value, an audible click can occur as shown in
Figure 17.
0dB Gain
6dB Gain
Left PGA Input
Left PGA Output
Right PGA Input
Right PGA Output
Click
Noise
Control Interface
Write
010100
to
R45[5:0]
Write
010100
to
R46[5:0]
R45[8]=0
R46[8]=1
Write Left PGA Volume
without update
Time
Write Right PGA Volume
with update
Figure 17 Click Noise during Volume Update
34
Rev 4.5
WM8983
In order to prevent this click noise, a zero cross function is provided. When enabled, this will cause
the PGA volume to update only when a zero crossing occurs, minimising click noise as shown in
Figure 18.
0dB Gain
6dB Gain
Left PGA Input
Left PGA Output
Zero crossings cause
volume updates
Right PGA Input
Right PGA Output
Control Interface
Write
010100
to
R45[5:0]
Write
010100
to
R46[5:0]
R45[8]=0
R46[8]=1
Write Left PGA Volume
without update
Time
Write Right PGA Volume
with update
Figure 18 Volume Update Using Zero Cross Detection
If there is a long period where no zero-crossing occurs, a timeout circuit in the WM8983 will
automatically update the volume. The volume updates will occur between one and two timeout
periods, depending on when the INPPGAVU bit is set as shown in Figure 19.
Left PGA Input
Left PGA Output
Zero crossing causes
volume update
Right PGA Input
No zero crossing
Timeout causes
volume update
Right PGA Output
Timeout Counter
Control Interface
Write
010100
to
R45[5:0]
Write
010100
to
R46[5:0]
R45[8]=0
R46[8]=1
Write Left PGA Volume
without update
Time
Write Right PGA Volume
with update
Figure 19 Volume Update after Timeout
Rev 4.5
35
WM8983
AUXILIARY INPUTS
There are two auxiliary inputs, AUXL and AUXR which can be used for a variety of purposes such as
stereo line inputs or as a ‘beep’ input signal to be mixed with the outputs.
As signal inputs, AUXL/R inputs can be used as a line input to the input BOOST stage which has
adjustable gain of -12dB to +6dB in 3dB steps, with an additional “off” state (i.e. not connected to ADC
input). See the INPUT BOOST section for further details.
The AUXL/R inputs can also be mixed into the output channel mixers, with a gain of -15dB to +6dB
plus off.
INPUT BOOST
Each of the stereo input PGA stages is followed by an input BOOST circuit. The input BOOST circuit
has 4 selectable inputs: the input microphone PGA output, the AUX amplifier output and the L2/R2
and AUXL/AUXR input pins (L2/R2 can be used as a line input, bypassing the input PGA). These four
inputs can be mixed together and have individual gain boost/adjust as shown in Figure 20.
Output from
OUT4 mixer
-12dB to + 6dB
OUT4_2ADCVOL, R42[8:6]
To Left OR Right
channel not both
OUT4_2LNR, R42[5]
-12dB to + 6dB
AUXL
AUXL2BOOSTVOL, R47[2:0]
Output from
input PGA
AUXL2BOOSTVOL=0
To ADC input
and/or
output mixers
0dB or +20dB
PGABOOSTL, R47[8]
INPPGAMUTEL, R45[6]
-12dB to + 6dB
L2
L2_2BOOSTVOL, R47[6:4]
Output from
OUT4 mixer
L2_2BOOSTVOL=000
-12dB to + 6dB
OUT4_2ADCVOL, R42[8:6]
To Left OR Right
channel not both
OUT4_2LNR, R42[5]
-12dB to + 6dB
AUXR
AUXR2BOOSTVOL, R48[2:0]
Output from
input PGA
AUXR2BOOSTVOL=0
To ADC input
and/or
output mixers
0dB or +20dB
PGABOOSTR, R48[8]
INPPGAMUTER, R46[6]
-12dB to + 6dB
R2
R2_2BOOSTVOL, R48[6:4]
R2_2BOOSTVOL=000
Figure 20 Input Boost Stage
36
Rev 4.5
WM8983
The input PGA paths can have a +20dB boost (PGABOOSTL/R=1) , a 0dB pass through
(PGABOOSTL/R=0) or be completely isolated from the input boost circuit (INPPGAMUTEL/R=1).
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R47
Left Input
BOOST
control
8
PGABOOSTL
1
Boost enable for left channel input
PGA:
0 = PGA output has +0dB gain through
input BOOST stage.
1 = PGA output has +20dB gain
through input BOOST stage.
R48
Right Input
BOOST
control
8
PGABOOSTR
1
Boost enable for right channel input
PGA:
0 = PGA output has +0dB gain through
input BOOST stage.
1 = PGA output has +20dB gain
through input BOOST stage.
Table 8 Input BOOST Stage Control
The Auxiliary amplifier path to the BOOST stages is controlled by the AUXL2BOOSTVOL[2:0] and
AUXR2BOOSTVOL[2:0] register bits. When AUXL2BOOSTVOL/AUXR2BOOSTVOL=000, this path is
completely disconnected from the BOOST stage. Settings 001 through to 111 control the gain in 3dB
steps from -12dB to +6dB.
The L2/R2 path to the BOOST stage is controlled by the L2_2BOOSTVOL[2:0] and the
R2_2BOOSTVOL[2:0] register bits. When L2_2BOOSTVOL/R2_2BOOSTVOL=000, the L2/R2 input
pin is completely disconnected from the BOOST stage. Settings 001 through to 111 control the gain
in 3dB steps from -12dB to +6dB.
The OUT4 mixer path to the BOOST stage is controlled by the OUT4_2ADCVOL[2:0] and
OUT4_2LNR register bits. The OUT4 mixer signal can be routed to the Left Boost or the Right Boost
stage, but not both at the same time. When OUT4_2ADCVOL=000, the OUT4 mixer path is
completely disconnected from the BOOST stage.
REGISTER
ADDRESS
R42
OUT4 to ADC
BIT
8:6
LABEL
OUT4_2ADCVOL
DEFAULT
000
DESCRIPTION
Controls the OUT4 to ADC input
boost stage:
000 = Path disabled
(disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
5
Rev 4.5
OUT4_2LNR
0
OUT4 to L or R ADC input
0 = Right ADC input
1 = Left ADC input
37
WM8983
REGISTER
ADDRESS
R47
Left channel
Input BOOST
control
BIT
2:0
LABEL
AUXL2BOOSTVOL
DEFAULT
000
DESCRIPTION
Controls the auxiliary amplifier to
the left channel input boost stage:
000 = Path disabled
(disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
R48
Right channel
Input BOOST
control
6:4
L2_2BOOSTVOL
000
Controls the L2 pin to the left
channel input boost stage:
000 = Path disabled
(disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
2:0
AUXR2BOOSTVOL
000
Controls the auxiliary amplifier to
the right channel input boost
stage:
000 = Path disabled
(disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
6:4
R2_2BOOSTVOL
000
Controls the R2 pin to the right
channel input boost stage:
000 = Path disabled
(disconnected)
001 = -12dB
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
Table 9 Input BOOST Stage Control
38
Rev 4.5
WM8983
The BOOST stage is enabled under control of the BOOSTEN register bit.
REGISTER
ADDRESS
R2
Power
management
2
BIT
LABEL
DEFAULT
DESCRIPTION
4
BOOSTENL
0
Left channel Input BOOST enable
0 = Boost stage OFF
1 = Boost stage ON
5
BOOSTENR
0
Right channel Input BOOST enable
0 = Boost stage OFF
1 = Boost stage ON
Table 10 Input BOOST Enable Control
MICROPHONE BIASING CIRCUIT
The MICBIAS output provides a low noise reference voltage suitable for biasing electret type
microphones and the associated external resistor biasing network. Refer to the Applications
Information section for recommended external components. The MICBIAS voltage can be altered via
the MBVSEL register bit. When MBVSEL=0, MICBIAS=0.9*AVDD1 and when MBVSEL=1,
MICBIAS=0.65*AVDD1. The output can be enabled or disabled using the MICBEN control bit.
REGISTER
ADDRESS
R1
Power
management 1
BIT
4
LABEL
MICBEN
DEFAULT
DESCRIPTION
0
Microphone Bias Enable
0 = OFF (high impedance output)
1 = ON
Table 11 Microphone Bias Enable Control
REGISTER
ADDRESS
R44
Input control
BIT
8
LABEL
MBVSEL
DEFAULT
0
DESCRIPTION
Microphone Bias Voltage Control
0 = 0.9 * AVDD1
1 = 0.65 * AVDD1
Table 12 Microphone Bias Voltage Control
The internal MICBIAS circuitry is shown in Figure 21. Note that the maximum source current
capability for MICBIAS is 3mA. The external biasing resistors therefore must be large enough to limit
the MICBIAS current to 3mA.
MICBE
N
internal
resistor
internal
resistor
MICBIAS
VMI
D
MBVSEL=0
MICBIA
SS
= 1.8 x VMID
= 0.9 X AVDD1
MBVSEL=1
MICBIA
S
= 1.3 x VMID
= 0.65 X AVDD1
AGND1
Figure 21 Microphone Bias Schematic
Rev 4.5
39
WM8983
ANALOGUE TO DIGITAL CONVERTER (ADC)
The WM8983 uses stereo multi-bit, oversampled sigma-delta ADCs. The use of multi-bit feedback
and high oversampling rates reduces the effects of jitter and high frequency noise. The ADC Full
Scale input level is proportional to AVDD1. With a 3.3V supply voltage, the full scale level is 1.0V rms.
Any voltage greater than full scale may overload the ADC and cause distortion.
ADC DIGITAL FILTERS
The ADC filters perform true 24 bit signal processing to convert the raw multi-bit oversampled data
from the ADC to the correct sampling frequency to be output on the digital audio interface. The digital
filter path for each ADC channel is illustrated in Figure 22.
ADC DIGITAL FILTERS
ADC
DIGITAL
DECIMATOR
DIGITAL
FILTERS
5-BAND
EQUALISER
GAIN
HIGH PASS
FILTER
NOTCH
FILTER
DIGITAL
AUDIO
INTERFACE
Figure 22 ADC Digital Filter Path
The ADCs are enabled by the ADCENL/R register bit.
REGISTER
ADDRESS
R2
Power
management 2
BIT
LABEL
DEFAULT
DESCRIPTION
0
ADCENL
0
Enable ADC left channel:
0 = ADC disabled
1 = ADC enabled
1
ADCENR
0
Enable ADC right channel:
0 = ADC disabled
1 = ADC enabled
Table 13 ADC Enable Control
The polarity of the output signal can also be changed under software control using the
ADCLPOL/ADCRPOL register bit. The oversampling rate of the ADC can be adjusted using the
ADCOSR128 register bit. With ADCOSR128=0 the oversample rate is 64x which gives lowest power
operation and when ADCOSR128=1 the oversample rate is 128x which gives best performance.
REGISTER
ADDRESS
R14
ADC Control
BIT
LABEL
DEFAULT
DESCRIPTION
0
ADCLPOL
0
ADC left channel polarity adjust:
0 = normal
1 = inverted
1
ADCRPOL
0
ADC right channel polarity adjust:
0 = normal
1 = inverted
3
ADCOSR128
0
ADC oversample rate select:
0 = 64x (lowest power)
1 = 128x (best performance)
Table 14 ADC Control
40
Rev 4.5
WM8983
SELECTABLE HIGH PASS FILTER
A selectable high pass filter is provided. To disable this filter, set HPFEN=0. The filter has two modes
controlled by HPFAPP. In Audio Mode (HPFAPP=0), the filter is first order, with a cut-off frequency of
3.7Hz. In Application Mode (HPFAPP=1), the filter is second order, with a cut-off frequency selectable
via the HPFCUT register. The cut-off frequencies when HPFAPP=1 are shown in Table 15.
REGISTER
ADDRESS
BIT
R14
ADC Control
LABEL
DEFAULT
8
HPFEN
1
7
HPFAPP
0
6:4
HPFCUT
000
DESCRIPTION
High Pass Filter Enable
0 = disabled
1 = enabled
Select audio mode or application mode
0 = Audio mode (1st order, fc = ~3.7Hz)
1 = Application mode (2nd order, fc =
HPFCUT)
Application mode cut-off frequency
See Table 16 for details.
Table 15 ADC Enable Control
HPFCUT
[2:0]
SR=101/100
SR=011/010
SR=001/000
fs (kHz)
8
11.025
12
16
22.05
24
32
44.1
48
000
82
113
001
102
141
122
82
113
153
102
141
122
82
113
122
153
102
141
010
131
180
156
131
153
180
156
131
180
011
163
225
245
196
163
225
245
163
225
100
204
281
245
306
204
281
306
204
281
101
261
306
360
392
261
360
392
261
360
392
110
111
327
450
490
327
450
490
327
450
490
408
563
612
408
563
612
408
563
612
Table 16 High Pass Filter Cut-off Frequencies (HPFAPP=1)
Note that the High Pass filter values (when HPFAPP=1) are calculated on the assumption that the SR
register bits are set correctly for the actual sample rate as shown in Table 16. Sampling rate (SR) is
selected using register bits R7[3:1].
Rev 4.5
41
WM8983
PROGRAMMABLE IIR NOTCH FILTER
A programmable notch filter is provided. This filter has a variable centre frequency and bandwidth,
programmable via two coefficients, a0 and a1. a0 and a1 are represented by the register bits
NFA0[13:0] and NFA1[13:0]. Because these coefficient values require four register writes to setup
there is an NFU (Notch Filter Update) flag which should be set only when all four registers are setup.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
6:0
NFA0[13:7]
0
Notch Filter a0 coefficient, bits [13:7]
7
NFEN
0
8
NFU
0
R28
Notch Filter 2
6:0
NFA0[6:0]
0
Notch filter enable:
0 = Disabled
1 = Enabled
Notch filter update. The notch filter
values used internally only update
when one of the NFU bits is set high.
Notch Filter a0 coefficient, bits [6:0]
8
NFU
0
R29
Notch Filter 3
6:0
NFA1[13:7]
0
8
NFU
0
R30
Notch Filter 4
0-6
NFA1[6:0]
0
8
NFU
0
R27
Notch Filter 1
Notch filter update. The notch filter
values used internally only update
when one of the NFU bits is set high.
Notch Filter a1 coefficient, bits [13:7]
Notch filter update. The notch filter
values used internally only update
when one of the NFU bits is set high.
Notch Filter a1 coefficient, bits [6:0]
Notch filter update. The notch filter
values used internally only update
when one of the NFU bits is set high.
Table 17 Notch Filter Function
The coefficients are calculated as follows:
a0 
1  tan(wb / 2)
1  tan(wb / 2)
a1  (1  a0 ) cos( w0 )
Where:
w0  2f c / f s
wb  2f b / f s
fc = centre frequency in Hz, fb = -3dB bandwidth in Hz, fs = sample frequency in Hz
The actual register values can be determined from the coefficients as follows:
NFA0 = -a0 x 213
NFA1 = -a1 x 212
42
Rev 4.5
WM8983
NOTCH FILTER WORKED EXAMPLE
The following example illustrates how to calculate the a0 and a1 coefficients for a desired centre
frequency and -3dB bandwidth.
Fc = 1000 Hz
fb = 100 Hz
fs = 48000 Hz
w0 
wb 
a0 
2f c
fs
2fb
fs
 1000 
  0.1308996939 rads
 48000 
 2 
 100 
  0.01308996939 rads
 48000 
 2 
1  tan (wb / 2 )
1  tan (wb / 2 )

1  tan ( 0 .01308996939 / 2 )
1  tan ( 0 .01308996939 / 2 )
 0 .9869949627
a1   (1  a0 ) cos(w0 )   (1  0.9869949627) cos(0.1308996939)  1.969995945
NFA0 = -a0 x 213 = -8085 (rounded to nearest whole number)
NFA1 = -a1 x 212 = 8069 (rounded to nearest whole number)
These values are then converted to a 2’s complement notation:
NFA0[13:0] = 14’h1F95; Converting to 2’s complement NFA0 = 14’h4000 – 14’h1F95 = 14’h206B
NFA1[13:0] = 14’h1F85; Converting to 2’s complement NFA0 = 14’h1F85
Rev 4.5
43
WM8983
DIGITAL ADC VOLUME CONTROL
The output of the ADCs can be digitally attenuated over a range from –127dB to 0dB in 0.5dB steps.
The gain for a given eight-bit code X is given by:
0.5  (G-255) dB for 1  G  255;
REGISTER
ADDRESS
R15
Left channel
ADC Digital
Volume
R16
Right channel
ADC Digital
Volume
BIT
LABEL
MUTE for G = 0
DEFAULT
DESCRIPTION
7:0
ADCLVOL
[7:0]
11111111
( 0dB )
Left ADC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
… 0.5dB steps up to
1111 1111 = 0dB
8
ADCVU
Not
latched
ADC left and ADC right volume do not
update until a 1 is written to ADCVU (in
reg 15 or 16)
7:0
ADCRVOL
[7:0]
11111111
( 0dB )
Right ADC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
8
ADCVU
Not
latched
ADC left and ADC right volume do not
update until a 1 is written to ADCVU (in
reg 15 or 16)
Table 18 ADC Digital Volume Control
INPUT LIMITER / AUTOMATIC LEVEL CONTROL (ALC)
The WM8983 has an automatic PGA gain control circuit, which can function as an input peak limiter or
as an automatic level control (ALC).
The Automatic Level Control (ALC) provides continuous adjustment of the input PGA in response to
the amplitude of the input signal. A digital peak detector monitors the input signal amplitude and
compares it to a register defined threshold level (ALCLVL).
If the signal is below the threshold, the ALC will increase the gain of the PGA at a rate set by
ALCDCY. If the signal is above the threshold, the ALC will reduce the gain of the PGA at a rate set by
ALCATK.
The ALC has two modes selected by the ALCMODE register: normal mode and peak limiter mode.
The ALC/limiter function is enabled by settings the register bits R32[8:7] ALCSEL.
44
REGISTER
ADDRESS
BIT
R32 (20h)
ALC Control
1
2:0
LABEL
ALCMIN
[2:0]
DEFAULT
000 (-12dB)
DESCRIPTION
Set minimum gain of PGA
000 = -12dB
001 = -6dB
010 = 0dB
011 = +6dB
100 = +12dB
101 = +18dB
110 = +24dB
111 = +30dB
Rev 4.5
WM8983
REGISTER
ADDRESS
R33 (21h)
ALC Control
2
R34 (22h)
ALC Control
3
Rev 4.5
BIT
LABEL
DEFAULT
DESCRIPTION
5:3
ALCMAX
[2:0]
111
(+35.25dB)
Set Maximum Gain of PGA
111 = +35.25dB
110 = +29.25dB
101 = +23.25dB
100 = +17.25dB
011 = +11.25dB
010 = +5.25dB
001 = -0.75dB
000 = -6.75dB
8:7
ALCSEL
00
ALC function select
00 = ALC disabled
01 = Right channel ALC enabled
10 = Left channel ALC enabled
11 = Both channels ALC enabled
3:0
ALCLVL
[3:0]
1011
(-6dB)
ALC target – sets signal level at ADC
input
1111 = -1.5dBFS
1110 = -1.5dBFS
1101 = -3dBFS
1100 = -4.5dBFS
1011 = -6dBFS
1010 = -7.5dBFS
1001 = -9dBFS
1000 = -10.5dBFS
0111 = -12dBFS
0110 = -13.5dBFS
0101 = -15dBFS
0100 = -16.5dBFS
0011 = -18dBFS
0010 = -19.5dBFS
0001 = -21dBFS
0000 = -22.5dBFS
7:4
ALCHLD
[3:0]
0000
(0ms)
ALC hold time before gain is
increased.
0000 = 0ms
0001 = 2.67ms
0010 = 5.33ms
0011 = 10.66ms
0100 = 21.32ms
0101 = 42.64ms
0110 = 85.28ms
0111 = 0.17s
1000 = 0.34s
1001 = 0.68s
1010 = 1.36s
1011 = 2.7s
1100 = 5.4s
1101 = 10.9s
1110 = 21.8 s
1111 = 43.7s
8
ALCMODE
0
Determines the ALC mode of
operation:
0 = ALC mode (Normal Operation)
1 = Limiter mode.
45
WM8983
REGISTER
ADDRESS
BIT
7:4
LABEL
ALCDCY
[3:0]
DEFAULT
DESCRIPTION
0011
(13ms/6dB)
Decay (gain ramp-up) time
(ALCMODE ==0)
Per
step
Per
6dB
90% of
range
0000
410us
3.3ms
24ms
0001
820us
6.6ms
48ms
0010
1.64ms
13.1ms
192ms
… (time doubles with every step)
1010
or
higher
0011
(2.9ms/6dB)
420ms
3.36s
24.576s
Decay (gain ramp-up) time
(ALCMODE ==1)
Per
step
Per
6dB
90% of
range
0000
90.8us
726.4us
5.26ms
0001
181.6us
1.453ms
10.53m
s
0010
363.2us
2.905ms
21.06m
s
… (time doubles with every step)
1010
3:0
ALCATK
[3:0]
0010
(832us/6dB)
93ms
744ms
5.39s
ALC attack (gain ramp-down) time
(ALCMODE == 0)
Per
step
Per
6dB
90% of
range
0000
104us
832us
6ms
0001
208us
1.66ms
12ms
0010
416us
3.32ms
24.1ms
… (time doubles with every step)
1010
or
higher
0010
(182us/6dB)
106ms
852ms
6.18s
ALC attack (gain ramp-down) time
(ALCMODE == 1)
Per
step
Per
6dB
90% of
range
0000
22.7us
182.4us
1.31ms
0001
45.4us
363.2us
2.62ms
0010
90.8us
726.4us
5.26ms
… (time doubles with every step)
1010
23.2ms
186ms
1.348s
Table 19 ALC Control Registers
When the ALC is disabled, the input PGA remains at the last controlled value of the ALC. An input
gain update must be made by writing to the INPPGAVOLL/R register bits.
46
Rev 4.5
WM8983
NORMAL MODE
In normal mode, the ALC will attempt to maintain a constant signal level by increasing or decreasing
the gain of the PGA. The following diagram shows an example of this.
Input
Signal
ALCSEL
tATK
PGA
Gain
tDCY
Vstep
Output
of PGA
ALCLVL
Figure 23 ALC Normal Mode Operation
Rev 4.5
47
WM8983
LIMITER MODE
In limiter mode, the ALC will reduce peaks that go above the threshold level, but will not increase the
PGA gain beyond the starting level. The starting level is the PGA gain setting when the ALC is
enabled in limiter mode. If the ALC is started in limiter mode, this is the gain setting of the PGA at
startup. If the ALC is switched into limiter mode after running in ALC mode, the starting gain will be
the gain at switchover. The diagram below shows an example of limiter mode.
Input
Signal
ALCSEL
tATKLIM
PGA
Gain
tDCYLIM
Vstep
Output
of PGA
ALCLVL
Figure 24 ALC Limiter Mode Operation
48
Rev 4.5
WM8983
ALC LIMITER MODE INITIALISATION SEQUENCE
In order to correctly initialise the ALC in limiter mode, the following sequence of register writes is
required. MCLK must be applied during the initialisation sequence
1. R45 - Set left input PGA gain (INPPGAVOLL) to level required for operation.
2. R46 - Set right input PGA gain (INPPGAVOLR) to level required for operation.
3. R44 - Enable analogue inputs as required.
4. R2 - Disable input PGA (INPPGAENL=0, INPPGAENR=0).
5. R59 = 0x0003 - Enable ALC test mode.
6. R32 - Set ALCMAX and ALCMIN to the level required for operation.
7. R33 - Set limiter level (ALCLVL) to the level required for operation.
8. R34 = 0x0000 - Enable ALC mode (ALCMODE = 0).
9. Insert 1ms delay to allow input PGA gain update by the limiter circuit.
10. R34 = 0x0100 - Enable Limiter mode (ALCMODE = 1).
11. Insert 1ms delay to allow input PGA gain update by the limiter circuit.
12. R59 = 0x0000 - Turn off ALC test mode.
13. R2 - Enable input PGA (INPPGAENL=1, INPPGAENR=1).
Note: R32, R33, R45 and R46 register settings above need to be changed to reflect settings required
in the target application.
ATTACK AND DECAY TIMES
The attack and decay times set the update times for the PGA gain. The attack time is the time
constant used when the gain is reducing. The decay time is the time constant used when the gain is
increasing. In limiter mode, the time constants are faster than in ALC mode. The time constants are
shown below in terms of a single gain step, a change of 6dB and a change of 90% of the PGAs gain
range.
Note that, these times will vary slightly depending on the sample rate used (specified by the SR
register).
NORMAL MODE
ALCMODE = 0 (Normal Mode)
ALCATK
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
Rev 4.5
tATK
104µs
208µs
416µs
832µs
1.66ms
3.33ms
6.66ms
13.32ms
26.64ms
53.28ms
106.6ms
Attack Time (s)
tATK6dB
tATK90%
832µs
6ms
1.66ms
12ms
3.33ms
24ms
6.66ms
48ms
13.32ms
96ms
26.64ms
192ms
53.28ms
384ms
106.6ms
768ms
213.2ms
1.53s
426.4ms
3.07s
852.8ms
6.14s
49
WM8983
ALCMODE = 0 (Normal Mode)
Decay Time (s)
ALCDCY
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
tDCY
410µs
820µs
1.64ms
3.28ms
6.56ms
13.12ms
26.24ms
52.5ms
105ms
210ms
420ms
tDCY6dB
3.3ms
6.6ms
13.1ms
26.2ms
52.5ms
105ms
210ms
420ms
840ms
1.68s
3.36s
tDCY90%
24ms
48ms
96ms
192ms
384ms
768ms
1.53s
3.07s
6.14s
12.28s
24.57s
Table 20 ALC Normal Mode (Attack and Decay times)
LIMITER MODE
ALCMODE = 1 (Limiter Mode)
ALCATK
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
tATKLIM
22.7µs
45.4µS
90.8µS
182µS
363µS
726µS
1.45ms
2.9ms
5.81ms
11.62ms
23.2ms
Attack Time (s)
tATKLIM6dB
tATKLIM90%
182.4µs
1.31ms
363.2µs
2.62ms
726.4µs
5.24ms
1.45ms
10.48ms
2.9ms
20.9ms
5.81ms
41.9ms
11.62ms
83.8ms
23.2ms
167.7ms
46.5ms
335.4ms
93ms
670.8ms
186ms
1.34s
ALCMODE = 1 (Limiter Mode)
ALCDCY
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
tDCYLIM
90.8µs
182µS
363µS
726µS
1.45ms
2.9ms
5.81ms
11.62ms
23.2ms
46.4ms
92.8ms
Attack Time (s)
tDCYLIM6dB
tDCYLIM90%
726.4µs
5.24ms
1.45ms
10.48ms
2.9ms
20.9ms
5.81ms
41.9ms
11.62ms
83.8ms
23.2ms
167.7ms
46.5ms
335.4ms
93ms
670.8ms
186ms
1.34s
372ms
2.68s
744ms
5.36s
Table 21 ALC Limiter Mode (Attack and Decay times)
50
Rev 4.5
WM8983
MINIMUM AND MAXIMUM GAIN
The ALCMIN and ALCMAX register bits set the minimum/maximum gain value that the PGA can be
set to whilst under the control of the ALC. This has no effect on the PGA when ALC is not enabled.
REGISTER
ADDRESS
BIT
R32
ALC Control
1
5:3
ALCMAX
111
Set Maximum Gain of PGA
(see Table 19 for definition)
2:0
ALCMIN
000
Set minimum gain of PGA
(see Table 19 for definition)
LABEL
DEFAULT
DESCRIPTION
Table 22 ALC Max/Min Gain
In normal mode, ALCMAX sets the maximum boost which can be applied to the signal. In limiter
mode, ALCMAX will normally have no effect (assuming the starting gain value is less than the
maximum gain specified by ALCMAX) because the maximum gain is set at the starting gain level.
ALCMIN sets the minimum gain value which can be applied to the signal.
PGA Gain = 111111 (+35.25dB)
ALCMAX
Whole PGA gain range
ALC operating range
ALCMIN
PGA Gain = 000000 (-12dB)
Figure 25 ALC Min/Max Gain
ALCMAX
111
110
101
100
011
010
001
000
Maximum Gain (dB)
35.25
29.25
23.25
17.25
11.25
5.25
-0.75
-6.75
Table 23 ALC Max Gain Values
Rev 4.5
51
WM8983
ALCMIN
000
001
010
011
100
101
110
111
Minimum Gain (dB)
-12
-6
0
6
12
18
24
30
Table 24 ALC Min Gain Values
Note that if the ALC gain setting strays outside the ALC operating range, either by starting the ALC
outside of the range or changing the ALCMAX or ALCMIN settings during operation, the ALC will
immediately adjust the gain to return to the ALC operating range. It is recommended that the ALC
starting gain is set between the ALCMAX and ALCMIN limits.
ALC HOLD TIME (NORMAL MODE ONLY)
In Normal mode, the ALC has an adjustable hold time which sets a time delay before the ALC begins
its decay phase (gain increasing). The hold time is set by the ALCHLD register.
REGISTER
ADDRESS
BIT
R33
ALC Control
2
7:4
LABEL
ALCHLD
DEFAULT
0000
DESCRIPTION
ALC hold time before gain is increased.
(see Table 19 for definition)
Table 25 ALC Hold Time
If the hold time is exceeded, this indicates that the signal has reached a new average level and the
ALC will increase the gain to adjust for that new average level. If the signal goes above the threshold
during the hold period, the hold phase is abandoned and the ALC returns to normal operation.
52
Rev 4.5
WM8983
Input
Signal
PGA
Gain
Output
of PGA
ALCLVL
Figure 26 ALCLVL
Input
Signal
tHOLD
PGA
Gain
Output
of PGA
ALCLVL
Figure 27 ALC Hold Time
Rev 4.5
53
WM8983
ALCHLD
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
tHOLD (s)
0
2.67ms
5.34ms
10.7ms
21.4ms
42.7ms
85.4ms
171ms
342ms
684ms
1.37s
Table 26 ALC Hold Time Values
PEAK LIMITER
To prevent clipping when a large signal occurs just after a period of quiet, the ALC circuit includes a
limiter function. If the ADC input signal exceeds 87.5% of full scale (–1.16dB), the PGA gain is
ramped down at the maximum attack rate (as when ALCATK = 0000), until the signal level falls below
87.5% of full scale. This function is automatically enabled whenever the ALC is enabled.
Note: If ALCATK = 0000, then the limiter makes no difference to the operation of the ALC. It is
designed to prevent clipping when long attack times are used.
NOISE GATE (NORMAL MODE ONLY)
When the signal is very quiet and consists mainly of noise, the ALC function may cause “noise
pumping”, i.e. loud hissing noise during silence periods. The WM8985 has a noise gate function that
prevents noise pumping by comparing the signal level at the input pins against a noise gate threshold,
NGTH. The noise gate cuts in when:
Signal level at ADC [dBFS] < NGTH [dBFS] + PGA gain [dB] + Mic Boost gain [dB]
This is equivalent to:
Signal level at input pin [dBFS] < NGTH [dBFS]
The PGA gain is then held constant (preventing it from ramping up as it normally would when the
signal is quiet).
The table below summarises the noise gate control register. The NGTH control bits set the noise gate
threshold with respect to the ADC full-scale range. The threshold is adjusted in 6dB steps. Levels at
the extremes of the range may cause inappropriate operation, so care should be taken with set–up of
the function. The noise gate only operates in conjunction with the ALC and cannot be used in limiter
mode.
54
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
R35 (23h)
ALC Noise Gate
Control
2:0
NGTH
000
ALC Noise gate threshold:
000 = -39dB
001 = -45dB
010 = -51dB
011 = -57dB
100 = -63dB
101 = -70dB
110 = -76dB
111 = -81dB
3
NGEN
0
ALC Noise gate function enable
1 = enable
0 = disable
LABEL
DEFAULT
DESCRIPTION
Table 27 ALC Noise Gate Control
The diagrams below show the response of the system to the same signal with and without noise gate.
Input
Signal
PGA
Gain
Output
of PGA
ALCLVL
Figure 28 ALC Operation Above Noise Gate Threshold
Rev 4.5
55
WM8983
Input
Signal
NGTH
PGA
Gain
Output
of PGA
ALCLVL
Figure 29 Noise Gate Operation
56
Rev 4.5
WM8983
OUTPUT SIGNAL PATH
The WM8983 output signal paths consist of digital application filters, up-sampling filters, stereo Hi-Fi
DACs, analogue mixers, stereo headphone and stereo line/mono/midrail output drivers. The digital
filters and DAC are enabled by register bits DACENL And DACENR. The mixers and output drivers
can be separately enabled by individual control bits (see Analogue Outputs). Thus it is possible to
utilise the analogue mixing and amplification provided by the WM8983, irrespective of whether the
DACs are running or not.
The WM8983 DACs receive digital input data on the DACDAT pin. The digital filter block processes
the data to provide the following functions:

Digital volume control

Graphic equaliser

A digital peak limiter.

Sigma-Delta Modulation
High performance sigma-delta audio DAC converts the digital data into an analogue signal.
DAC DIGITAL FILTERS
DIGITAL
AUDIO
INTERFACE
DIGITAL
GAIN
5-BAND
EQUALISER
DIGITAL
PEAK
LIMITER
3D
ENHANCE
DIGITAL
FILTERS
INTERP
SDM
DAC
Figure 30 DAC Digital Filter Path
The analogue outputs from the DACs can then be mixed with the aux analogue inputs and the ADC
analogue inputs. The mix is fed to the output drivers for headphone (LOUT1/ROUT1, LOUT2/ROUT2)
or line (OUT3/OUT4). OUT3 and OUT4 have additional mixers which allow them to output different
signals to the headphone and line outputs.
DIGITAL PLAYBACK (DAC) PATH
Digital data is passed to the WM8983 via the flexible audio interface and is then passed through a
variety of advanced digital filters as shown in Figure 30 to the hi-fi DACs. The DACs are enabled by
the DACENL/R register bits.
REGISTER
ADDRESS
R3
Power
Management 3
BIT
LABEL
DEFAULT
DESCRIPTION
0
DACENL
0
Left channel DAC enable
0 = DAC disabled
1 = DAC enabled
1
DACENR
0
Right channel DAC enable
0 = DAC disabled
1 = DAC enabled
Table 28 DAC Enable Control
Rev 4.5
57
WM8983
The WM8983 also has a Soft Mute function, which when enabled, gradually attenuates the volume of
the digital signal to zero. When disabled, the gain will ramp back up to the digital gain setting. This
function is enabled by default. To play back an audio signal, it must first be disabled by setting the
SOFTMUTE bit to zero.
REGISTER
ADDRESS
R10
DAC Control
BIT
LABEL
DEFAULT
DESCRIPTION
0
DACLPOL
0
Left DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
1
DACRPOL
0
Right DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
2
AMUTE
0
Automute enable
0 = Amute disabled
1 = Amute enabled
3
DACOSR128
0
DAC oversampling rate:
0 = 64x (lowest power)
1 = 128x (best performance)
6
SOFTMUTE
0
Softmute enable:
0 = Enabled
1 = Disabled
Table 29 DAC Control Register
The digital audio data is converted to oversampled bit streams in the on-chip, true 24-bit digital
interpolation filters. The bitstream data enters the multi-bit, sigma-delta DACs, which convert it to a
high quality analogue audio signal. The multi-bit DAC architecture reduces high frequency noise and
sensitivity to clock jitter. It also uses a Dynamic Element Matching technique for high linearity and low
distortion.
The DAC output phase defaults to non-inverted. Setting DACLPOL will invert the DAC output phase
on the left channel and DACRPOL inverts the phase on the right channel.
AUTO-MUTE
The DAC has an auto-mute function which applies an analogue mute when 1024 consecutive zeros
are detected. The mute is released as soon as a non-zero sample is detected. Auto-mute can be
disabled using the AMUTE control bit.
58
Rev 4.5
WM8983
DIGITAL HI-FI DAC VOLUME (GAIN) CONTROL
The signal volume from each Hi-Fi DAC can be controlled digitally. The gain range is –127dB to 0dB
in 0.5dB steps. The level of attenuation for an eight-bit code X is given by:
0.5  (X-255) dB for 1  X  255;
REGISTER
ADDRESS
R11
Left DAC
Digital Volume
R12
Right DAC
Digital Volume
BIT
LABEL
MUTE for X = 0
DEFAULT
DESCRIPTION
7:0
DACLVOL
[7:0]
11111111
( 0dB )
Left DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
8
DACVU
Not
latched
DAC left and DAC right volume do
not update until a 1 is written to
DACVU (in reg 11 or 12)
7:0
DACRVOL
[7:0]
11111111
( 0dB )
Right DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
8
DACVU
Not
latched
DAC left and DAC right volume do
not update until a 1 is written to
DACVU (in reg 11 or 12)
Table 30 DAC Digital Volume Control
Note: An additional gain of up to 12dB can be added using the gain block embedded in the digital
peak limiter circuit (see DAC DIGITAL OUTPUT LIMITER section).
5-BAND EQUALISER
A 5-band graphic equaliser function which can be used to change the output frequency levels to suit
the environment. This can be applied to the ADC or DAC path and is described in the 5-BAND
GRAPHIC EQUALISER section for further details on this feature.
3-D ENHANCEMENT
The WM8983 has an advanced digital 3-D enhancement feature which can be used to vary the
perceived stereo separation of the left and right channels. Like the 5-band equaliser, this feature can
be applied to either the ADC record path or the DAC playback path but not both simultaneously.
Refer to the 3D STEREO ENHANCEMENT section for further details on this feature.
DAC DIGITAL OUTPUT LIMITER
The WM8983 has a digital output limiter function. The operation of this is shown in Figure 31. In this
diagram, the upper graph shows the envelope of the input/output signals and the lower graph shows
the gain characteristic.
Rev 4.5
59
WM8983
input
Upper
Threshold
0.5dB
LIMLVL
output
0.5dB
Lower
Threshold
Gain
0dB
-0.5dB
-1dB
Figure 31 DAC Digital Limiter Operation
The limiter has a programmable upper threshold which is close to 0dB. Referring to Figure 31, in
normal operation (LIMBOOST=000 => limit only), signals below this threshold are unaffected by the
limiter. Signals above the upper threshold are attenuated at a specific attack rate (set by the LIMATK
register bits) until the signal falls below the threshold. The limiter also has a lower threshold 1dB
below the upper threshold. When the signal falls below the lower threshold, the signal is amplified at
a specific decay rate (controlled by LIMDCY register bits) until a gain of 0dB is reached. Both
threshold levels are controlled by the LIMLVL register bits. The upper threshold is 0.5dB above the
value programmed by LIMLVL, and the lower threshold is 0.5dB below the LIMLVL value.
VOLUME BOOST
The limiter has programmable upper gain which boosts signals below the threshold to compress the
dynamic range of the signal and increase its perceived loudness. This operates as an ALC function
with limited boost capability. The volume boost is from 0dB to +12dB in 1dB steps, controlled by the
LIMBOOST register bits.
The output limiter volume boost can also be used as a stand alone digital gain boost when the limiter
is disabled.
60
Rev 4.5
WM8983
REGISTER
ADDRESS
R24
DAC digital
limiter control
1
R25
DAC digital
limiter control
2
BIT
LABEL
DEFAULT
3:0
LIMATK
0010
7:4
LIMDCY
0011
8
LIMEN
0
3:0
LIMBOOST
0000
6:4
LIMLVL
000
DESCRIPTION
DAC Limiter Attack time (per 6dB gain
change) for 44.1kHz sampling. Note
that these are proportionally related to
sample rate.
0000 = 94us
0001 = 188s
0010 = 375us
0011 = 750us
0100 = 1.5ms
0101 = 3ms
0110 = 6ms
0111 = 12ms
1000 = 24ms
1001 = 48ms
1010 = 96ms
1011 to 1111 = 192ms
DAC Limiter Decay time (per 6dB gain
change) for 44.1kHz sampling. Note
that these are proportionally related to
sample rate:
0000 = 750us
0001 = 1.5ms
0010 = 3ms
0011 = 6ms
0100 = 12ms
0101 = 24ms
0110 = 48ms
0111 = 96ms
1000 = 192ms
1001 = 384ms
1010 = 768ms
1011 to 1111 = 1.536s
Enable the DAC digital limiter:
0 = disabled
1 = enabled
DAC Limiter volume boost (can be used
as a stand alone volume boost when
LIMEN=0):
0000 = 0dB
0001 = +1dB
0010 = +2dB
0011 = +3dB
0100 = +4dB
0101 = +5dB
0110 = +6dB
0111 = +7dB
1000 = +8dB
1001 = +9dB
1010 = +10dB
1011 = +11dB
1100 = +12dB
1101 to 1111 = reserved
Programmable signal threshold level
(determines level at which the DAC
limiter starts to operate)
000 = -1dB
001 = -2dB
010 = -3dB
011 = -4dB
100 = -5dB
101 to 111 = -6dB
Table 31 DAC Digital Limiter Control
Rev 4.5
61
WM8983
5-BAND GRAPHIC EQUALISER
A 5-band graphic equaliser is provided, which can be applied to the ADC or DAC path, together with
3D enhancement, under control of the EQ3DMODE register bit.
REGISTER
ADDRESS
R18
EQ Control 1
BIT
8
LABEL
EQ3DMODE
DEFAULT
1
DESCRIPTION
0 = Equaliser and 3D Enhancement
applied to ADC path
1 = Equaliser and 3D Enhancement
applied to DAC path
Table 32 EQ and 3D Enhancement DAC or ADC Path Select
Note: The ADCs and DACs must be disabled before changing the EQ3DMODE bit.
The equaliser consists of low and high frequency shelving filters (Band 1 and 5) and three peak filters
for the centre bands. Each has adjustable cut-off or centre frequency, and selectable boost (+/- 12dB
in 1dB steps). The peak filters have selectable bandwidth.
REGISTER
ADDRESS
R18
EQ Band 1
Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ1G
01100
(0dB)
EQ Band 1 Gain Control. See Table 38
for details.
6:5
EQ1C
01
EQ Band 1 Cut-off Frequency:
00 = 80Hz
01 = 105Hz
10 = 135Hz
11 = 175Hz
Table 33 EQ Band 1 Control
REGISTER
ADDRESS
R19
EQ Band 2
Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ2G
01100
(0dB)
EQ Band 2 Gain Control. See Table 38
for details.
6:5
EQ2C
01
8
EQ2BW
0
EQ Band 2 Centre Frequency:
00 = 230Hz
01 = 300Hz
10 = 385Hz
11 = 500Hz
EQ Band 2 Bandwidth Control
0 = narrow bandwidth
1 = wide bandwidth
Table 34 EQ Band 2 Control
REGISTER
ADDRESS
R20
EQ Band 3
Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ3G
01100
(0dB)
EQ Band 3 Gain Control. See Table 38
for details.
6:5
EQ3C
01
8
EQ3BW
0
EQ Band 3 Centre Frequency:
00 = 650Hz
01 = 850Hz
10 = 1.1kHz
11 = 1.4kHz
EQ Band 3 Bandwidth Control
0 = narrow bandwidth
1 = wide bandwidth
Table 35 EQ Band 3 Control
62
Rev 4.5
WM8983
REGISTER
ADDRESS
R21
EQ Band 4
Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ4G
01100
(0dB)
EQ Band 4 Gain Control. See Table 38
for details
6:5
EQ4C
01
8
EQ4BW
0
EQ Band 4 Centre Frequency:
00 = 1.8kHz
01 = 2.4kHz
10 = 3.2kHz
11 = 4.1kHz
EQ Band 4 Bandwidth Control
0 = narrow bandwidth
1 = wide bandwidth
Table 36 EQ Band 4 Control
REGISTER
ADDRESS
R22
EQ Band 5
Gain Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ5G
01100
(0dB)
EQ Band 5 Gain Control. See Table 38
for details.
6:5
EQ5C
01
EQ Band 5 Cut-off Frequency:
00 = 5.3kHz
01 = 6.9kHz
10 = 9kHz
11 = 11.7kHz
Table 37 EQ Band 5 Control
GAIN REGISTER
GAIN
00000
+12dB
00001
+11dB
00010
+10dB
00011
+9dB
00100
+8dB
00101
+7dB
00110
+6dB
00111
+5dB
01000
+4dB
01001
+3dB
01010
+2dB
01011
+1dB
01100
0dB
01101
-1dB
11000
-12dB
11001 to 11111
Reserved
Table 38 Gain Register Table
See also Figure 60 to Figure 77 for equaliser and high pass filter responses.
Rev 4.5
63
WM8983
3D STEREO ENHANCEMENT
The WM8983 has a digital 3D enhancement option to increase the perceived separation between the
left and right channels. Selection of 3D for record or playback is controlled by register bit
EQ3DMODE. Switching this bit from record to playback or from playback to record may only be done
when ADC and DAC are disabled. The WM8983 control interface will only allow EQ3DMODE to be
changed when ADC and DAC are disabled (ie ADCENL = 0, ADCENR = 0, DACENL = 0 and
DACENR = 0).
The DEPTH3D setting controls the degree of stereo expansion.
REGISTER
ADDRESS
R41 (29h)
3D Control
BIT
3:0
LABEL
DEPTH3D[3:0]
DEFAULT
0000
DESCRIPTION
Stereo depth
0000 = Disabled
0001 = 6.67%
0010 = 13.3%
0011 = 20%
0100 = 26.7%
0101 = 33.3%
0110 = 40%
0111 = 46.6%
1000 = 53.3%
1001 = 60%
1010 = 66.7%
1011 = 73.3%
1100 = 80%
1101 = 86.7%
1110 = 93.3%
1111 = 100% (maximum 3D effect)
Table 39 3D Stereo Enhancement Function
Note: When 3D enhancement is used, it may be necessary to attenuate the signal by 6dB to avoid
limiting.
ANALOGUE OUTPUTS
The WM8983 has three sets of stereo analogue outputs. These are:

LOUT1 and ROUT1 which are normally used to drive a headphone load.

LOUT2 and ROUT2 – which can be used as speaker, headphone or line drivers.

OUT3 and OUT4 – can be configured as a stereo line out (OUT3 is left output and OUT4 is
right output). OUT4 can also be used to provide a mono mix of left and right channels.
The outputs LOUT2, ROUT2 OUT3 and OUT4 are powered from AVDD2 and are capable of driving a
1V rms signal (AVDD1/3.3) in non-boost mode and AVDD1*1.5/3.3 in boost mode.
LOUT1 and ROUT1 are supplied from AVDD1 and can drive out a 1V rms signal (AVDD1/3.3).
LOUT1, ROUT1, LOUT2 and ROUT2 have individual analogue volume PGAs with -57dB to +6dB gain
ranges.
There are four output mixers in the output signal path, the left and right channel mixers which control
the signals to headphone (and optionally the line outputs) and also dedicated OUT3 and OUT4
mixers.
64
Rev 4.5
WM8983
LEFT AND RIGHT OUTPUT CHANNEL MIXERS
The left and right output channel mixers are shown in Figure 32. These mixers allow the AUX inputs,
the ADC bypass and the DAC left and right channels to be combined as desired. This allows a mono
mix of the DAC channels to be performed as well as mixing in external line-in from the AUX or speech
from the input bypass path.
The AUX and bypass inputs have individual volume control from -15dB to +6dB, and the DAC volume
can be adjusted in the digital domain if required. The output of these mixers is connected to the
headphone outputs (LOUT1, ROUT1, LOUT2 and ROUT2) and can optionally be connected to the
OUT3 and OUT4 mixers.
-15dB to + 6dB
AUXL
AUXLMIXVOL, R50[8:6]
AUXL2LMIX, R50[5]
LEFT OUTPUT
CHANNEL
MIXER
-15dB to +6dB
Output from
left channel
input boost stage
(BYPASS)
Output from
right channel
input boost stage
(BYPASS)
BYPLMIXVOL, R50[4:2]
-15dB to +6dB
BYPL2LMIX, R50[1]
BYPRMIXVOL, R51[4:2]
BYPR2LMIX, R43[7]
To:
LOUT1 volume ctrl,
LOUT2, volume ctrl
OUT3 mixer,
OUT4 mixer
Left DAC output
DAC2LMIX, R50[0]
Right DAC output
DACR2LMIX, R49[5]
-15dB to + 6dB
AUXR
AUXRMIXVOL, R51[8:6]
AUXR2RMIX, R51[5]
-15dB to +6dB
RIGHT OUTPUT
CHANNEL
MIXER
Output from
right channel
input boost stage
(BYPASS)
Output from
left channel
input boost stage
(BYPASS)
BYPRMIXVOL, R51[4:2]
-15dB to +6dB
BYPR2RMIX, R51[1]
BYPLMIXVOL, R50[4:2]
BYPL2RMIX, R43[8]
To:
ROUT1 volume ctrl,
ROUT2, volume ctrl
OUT3 mixer,
OUT4 mixer
Left DAC output
DACL2RMIX, R49[6]
Right DAC output
DACR2RMIX, R51[0]
Figure 32 Left/Right Output Channel Mixers
Rev 4.5
65
WM8983
REGISTER
ADDRESS
R43
Output mixer
control
R49
Output mixer
control
R50
Left channel
output mixer
control
BIT
LABEL
DEFAULT
DESCRIPTION
8
BYPL2RMIX
0
Left bypass path (from the Left
channel input PGA stage) to right
output mixer
0 = not selected
1 = selected
7
BYPR2LMIX
0
Right bypass path (from the right
channel input PGA stage) to Left
output mixer
0 = not selected
1 = selected
5
DACR2LMIX
0
Right DAC output to left output mixer
0 = not selected
1 = selected
6
DACL2RMIX
0
Left DAC output to right output mixer
0 = not selected
1 = selected
0
DACL2LMIX
1
Left DAC output to left output mixer
0 = not selected
1 = selected
1
BYPL2LMIX
0
Left bypass path (from the left
channel input PGA stage) to left
output mixer
0 = not selected
1 = selected
4:2
BYPLMIXVOL
5
AUXL2LMIX
000
0
Left bypass volume control to output
channel mixer:
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
Left Auxiliary input to left channel
output mixer:
0 = not selected
1 = selected
8:6
66
AUXLMIXVOL
000
Aux left channel input to left mixer
volume control:
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
Rev 4.5
WM8983
REGISTER
ADDRESS
R51
Right channel
output mixer
control
BIT
LABEL
DEFAULT
DESCRIPTION
0
DACR2RMIX
1
Right DAC output to right output
mixer
0 = not selected
1 = selected
1
BYPR2RMIX
0
Right bypass path (from the right
channel input PGA stage) to right
output mixer
0 = not selected
1 = selected
4:2
BYPRMIXVOL
000
Right bypass volume control to
output channel mixer:
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
5
AUXR2RMIX
8:6
AUXRMIXVOL
0
Right Auxiliary input to right channel
output mixer:
0 = not selected
1 = selected
000
Aux right channel input to right mixer
volume control:
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
R3
Power
management
3
2
LMIXEN
0
Left output channel mixer enable:
0 = disabled
1 = enabled
3
RMIXEN
0
Right output channel mixer enable:
0 = disabled
1 = enabled
Table 40 Left and Right Output Mixer Control
Rev 4.5
67
WM8983
HEADPHONE OUTPUTS (LOUT1 AND ROUT1)
The headphone outputs LOUT1 and ROUT1 can drive a 16 or 32 headphone load, either through
DC blocking capacitors, or DC-coupled to a buffered midrail reference as shown in Figure 33. OUT3,
OUT4, LOUT2 or ROUT2 could be used as this buffered reference if one of these outputs is not being
used, saving decoupling capacitors, at the expense of increased power consumption. For fully
independent left and right channels, two separate midrail references can be used, eliminating
crosstalk caused by headphone ground impedances, at the expense of increased power
consumption.
Headphone Output using DC Blocking Capacitors:
LOUT1
C1 220uF
Lowest power consumption (Two outputs enabled);
Large and expensive capacitors;
Bass response may be reduced for smaller capacitors;
Impedance in common ground may introduce crosstalk.
ROUT1
WM8983
C2 220uF
AGND1 (= 0V)
DC Coupled Headphone Output:
LOUT1
WM8983
Higher power consumption (Three outputs enabled);
Improved PSRR if AVDD2 connected to AVDD1;
Impedance in common ground may introduce crosstalk;
Improved bass response (DC connection).
ROUT1
LOUT2/ROUT2/OUT3/OUT4
= ‘MUTE’ => VMID
DC Coupled with Fully Independent Left / Right Drive:
LOUT1
L
ROUT1
WM8983
LOUT2/OUT3
= ‘MUTE’ => VMID
R
ROUT2/OUT4
= ‘MUTE’ => VMID
Highest power consumption (Four outputs enabled);
Improved PSRR if AVDD2 connected to AVDD1;
Independent L/R pseudo-ground eliminates crosstalk;
Improved bass response (DC connection);
Non-standard headphone connection may not be suitable
for some applications.
Figure 33 Recommended Headphone Output Configurations
Each headphone output has an analogue volume control PGA with a gain range of -57dB to +6dB.
When DC blocking capacitors are used, their capacitance and the load resistance together determine
the lower cut-off frequency of the output signal, fc. Increasing the capacitance lowers fc, improving the
bass response. Smaller capacitance values will diminish the bass response. Assuming a 16 load
and C1, C2 = 220F:
fc = 1 / 2 RLC1 = 1 / (2 x 16 x 220F) = 45 Hz
In the DC coupled configuration, the headphone “ground” is connected to the VMID pin. The OUT3/4
pins can be configured as a DC output driver by setting the OUT3MUTE and OUT4MUTE register bit.
The DC voltage on VMID in this configuration is equal to the DC offset on the LOUT1 and ROUT1
pins; therefore, no DC blocking capacitors are required. This saves space and material cost in
portable applications.
Note that LOUT2, ROUT2, OUT3 and OUT4 have an optional output boost of 1.5x. When these are
configured in this output boost mode (SPKBOOST/OUT3BOOST/OUT4BOOST=1), then the VMID
value of these outputs will be equal to 1.5xAVDD/2 and will not match the VMID of the headphone
drivers. Do not use the DC coupled output mode in this configuration.
68
Rev 4.5
WM8983
It is recommended to connect the DC coupled outputs only to headphones, and not to the line input of
another device. Although the built-in short circuit protection will prevent any damage to the headphone
outputs, such a connection may be noisy, and may not function properly if the other device is
grounded.
REGISTER
ADDRESS
R52
LOUT1
Volume
control
R53
ROUT1
Volume
control
BIT
LABEL
DEFAULT
DESCRIPTION
7
LOUT1ZC
0
Headphone volume zero cross
enable:
1 = Change gain on zero cross only
0 = Change gain immediately
6
LOUT1MUTE
0
Left headphone output mute:
0 = Normal operation
1 = Mute
5:0
LOUT1VOL
8
OUT1VU
7
111001
Left headphone output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
Not latched
LOUT1 and ROUT1 volumes do not
update until a 1 is written to
OUT1VU (in reg 52 or 53)
ROUT1ZC
0
Headphone volume zero cross
enable:
1 = Change gain on zero cross only
0 = Change gain immediately
6
ROUT1MUTE
0
Right headphone output mute:
0 = Normal operation
1 = Mute
5:0
ROUT1VOL
8
OUT1VU
111001
Not latched
Right headphone output volume:
000000 = -57dB
000001 = -56dB
…
111001 = 0dB
...
111111 = +6dB
LOUT1 and ROUT1 volumes do not
update until a 1 is written to
OUT1VU (in reg 52 or 53)
Table 41 OUT1 Volume Control
Rev 4.5
69
WM8983
SPEAKER OUTPUTS (LOUT2 AND ROUT2)
The outputs LOUT2 and ROUT2 are designed to drive an 8Ω BTL speaker but can optionally drive
two headphone loads of 16/32 or a line output (see Headphone Output and Line Output sections,
respectively). Each output has an individual volume control PGA, an output boost/level shift bit, a
mute and an enable as shown in Figure 34. LOUT2 and ROUT2 output the left and right channel
mixer outputs respectively.
The ROUT2 signal path also has an optional invert function; this is controlled using the INVROUT2
register bit.
AVDD2
0dB or 3.52dB
From left
output channel
mixer
LOUT2
SPKBOOST
R49[2]
LOUT2VOL
R54[5:0]
SPKBOOST GAIN DC output
1x 1x(AVDD1/2)
0
1.5x 1.5x(AVDD1/2)
1
VSPKR = L-(-R)
= L+R
0dB or 3.52dB
From right
output channel
mixer
ROUT2
ROUT2VOL
R55[5:0]
-1
AGND2
INVROUT2
R43[4]
BUFDCOPEN
R1[8]
AVDD/2
1.5xAVDD/2
0.5R
+
-
Sets DC level on
output stages that
are configured for
1.5x gain boost.
R
Figure 34 Speaker Outputs LOUT2 and ROUT2
70
Rev 4.5
WM8983
SPEAKER BOOST MODE
To support speaker boost mode, AVDD2 should be at least 1.5*AVDD1. A higher AVDD2 will improve
THD performance at the expense of power consumption while lower AVDD2 will cause clipping.
Variations in AVDD1 and AVDD2 should be taken into account when using speaker boost mode as
shown in Figure 35 and Figure 36.
AVDD2 > AVDD1
AVDD2 = 4.2V
5V
Extra headroom improves THD
but increases power
consumption
AVDD2 > AVDD1*1.5
AVDD1 = 3.3V
3V
OUTPUT
STAGE
SPKBOOST=0
AGND
3V
2V
OUTPUT
STAGE
SPKBOOST=1
MIXER
1V
0V
AGND
AGND
MIXER
AGND
AVDD2 = 2.9V
1V
0V
Clipping
AVDD2 > AVDD1*1.5
4V
AVDD2 < AVDD1
2V
AGND
5V
Clipping
AVDD1 = 3.3V
5V
4V
AVDD1 = 3.3V
MIXER
AVDD2 = 5V
4V
5V
AVDD2 = 4.2V
4V
AVDD1 = 3.3V
3V
3V
OUTPUT
STAGE
SPKBOOST=0
2V
OUTPUT
STAGE
SPKBOOST=1
MIXER
2V
1V
1V
AGND
0V
AGND
Figure 35 Non-Boost Mode Output Operation
0V
AGND
Figure 36 Boost Mode Output Operation
LOUT2 and ROUT2 outputs can be connected directly to a Lithium battery to improve THD
performance in non-boost mode. When using a 4.2V lithium battery, maximum power output is
achieved without using speaker boost and by setting AVDD1 = 3.6V.
Although direct battery connection is also possible in boost mode, the discharge characteristic of the
battery can lead to clipping after a relatively short period of time as shown in Figure 37. Reducing the
maximum permitted volume and keeping AVDD1 to a minimum will allow boost mode to operate for
longer.
Battery
discharging
AVDD2 = VBATT
time
4V
3V
AVDD1 = 2.5V
MIXER
AVDD1 / 2
AGND1
5V
OUTPUT
AVDD1*0.75
STAGE
SPKBOOST=1
AGND2
2V
1V
0V
Reduce max volume
to prevent clipping
Reduce max volume
to prevent clipping
Figure 37 Output Boost Mode with Direct Battery Connection
As the full scale output falls close to AVDD1, it becomes more effective to use non-boost mode to
generate a louder output, although SPKBOOST should NOT be changed while the speaker output is
driving out a signal. As a general rule:
if AVDD2 - (AVDD1 * 0.75) > AVDD1 / 2 boost mode provides more power output;
if AVDD2 - (AVDD1 * 0.75) < AVDD1 / 2 non-boost mode provides more power output.
Rev 4.5
71
WM8983
REGISTER
ADDRESS
R54
LOUT2
Volume
control
R55
ROUT2
Volume
control
BIT
7
LABEL
LOUT2ZC
DEFAULT
0
DESCRIPTION
Left speaker volume zero cross
enable:
1 = Change gain on zero cross only
0 = Change gain immediately
6
LOUT2MUTE
5:0
LOUT2VOL
8
OUT2VU
7
ROUT2ZC
0
111001
Not latched
0
Left speaker output mute:
0 = Normal operation
1 = Mute
Left speaker output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
LOUT2 and ROUT2 volumes do not
update until a 1 is written to
OUT2VU (in reg 54 or 55)
Right speaker volume zero cross
enable:
1 = Change gain on zero cross only
0 = Change gain immediately
6
ROUT2MUTE
5:0
ROUT2VOL
8
OUT2VU
0
111001
Not latched
Right speaker output mute:
0 = Normal operation
1 = Mute
Right speaker output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
LOUT2 and ROUT2 volumes do not
update until a 1 is written to
OUT2VU (in reg 54 or 55)
Table 42 OUT2 Volume Control
The signal output on LOUT2/ROUT2 comes from the Left/Right Mixer circuits and can be any
combination of the DAC output, the Bypass path (output of the input boost stage) and the AUX input.
The LOUT2/ROUT2 volume is controlled by the LOUT2VOL/ ROUT2VOL register bits. Gains over
0dB may cause clipping if the signal is large. The LOUT2MUTE/ ROUT2MUTE register bits cause the
speaker outputs to be muted (the output DC level is driven out). The output pins remain at the same
DC level (DCOP), so that no click noise is produced when muting or un-muting
The speaker output stages also have a selectable gain boost of 1.5x (3.52dB). When this boost is
enabled, the output DC level is also level shifted (from AVDD1/2 to 1.5xAVDD1/2) to prevent the
signal from clipping. A dedicated amplifier BUFDCOP, as shown in Figure 34 , is used to perform the
DC level shift operation. This buffer must be enabled using the BUFDCOPEN register bit for this
operating mode. It should also be noted that if AVDD2 is not equal to or greater than 1.5xAVDD1 this
boost mode may result in signals clipping. Table 44 summarises the effect of the SPKBOOST control
bits.
72
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R49
Output control
2
SPKBOOST
0
Speaker Gain
0 = speaker gain = -1;
DC = AVDD1 / 2
1 = speaker gain = +1.5;
DC = 1.5 x AVDD1 / 2
R1
Power
management
1
8
BUFDCOPEN
0
Output stage 1.5xAVDD/2 driver
enable
0 = Buffer disabled
1 = Buffer enabled (required for 1.5x
gain boost)
Table 43 Speaker Boost Stage Control
SPKBOOST
OUTPUT
STAGE GAIN
OUTPUT STAGE
CONFIGURATION
OUTPUT DC
LEVEL
0
1x (0dB)
AVDD1/2
Inverting
1
1.5x (3.52dB)
1.5xAVDD1/2
Non-inverting
Table 44 Output Boost Stage Details
REGISTER
ADDRESS
R43
Beep control
BIT
4
LABEL
DEFAULT
INVROUT2
0
DESCRIPTION
Invert ROUT2 output
0 = Not inverted
1 = Inverted
Table 45 ROUT2 Phase Invert Control
ZERO CROSS TIMEOUT
A zero-cross timeout function is provided so that if zero cross is enabled on the input or output PGAs,
the gain will automatically update after a timeout period if a zero cross has not occurred. This is
enabled by setting SLOWCLKEN. The timeout period is dependent on the clock input to the digital
and is equal to 221 * SYSCLK period.
REGISTER
ADDRESS
R7
Additional
Control
BIT
0
LABEL
SLOWCLKEN
DEFAULT
0
DESCRIPTION
Slow clock enable.
Used for both the jack insert detect
debounce circuit and the zero cross
timeout.
0 = slow clock disabled
1 = slow clock enabled
Table 46 Timeout Clock Enable Control
Note: SLOWCLKEN is also used for the jack insert detect debounce circuit
Rev 4.5
73
WM8983
OUT3/OUT4 MIXERS AND OUTPUT STAGES
The OUT3/OUT4 pins provide an additional stereo line output, a mono output, or a pseudo ground
connection for headphones. There is a dedicated analogue mixer for OUT3 and one for OUT4 as
shown in Figure 38.
The OUT3 and OUT4 output stages are powered from AVDD2 and AGND2. These individuallycontrollable outputs also incorporate an optional 1.5x boost and level shifting stage.
Left DAC
output
LDAC2OUT3, R56[0]
Left mixer
output
LMIX2OUT3, R56[1]
OUT3
MIXER
To
OUT3
output
stage
Left
bypass
BYPL2OUT3, R56[2]
OUT4_2OUT3, R56[3]
OUT3_2OUT4, R57[7]
Right DAC
output
RDAC2OUT4, R57[0]
Right mixer
output
RMIX2OUT4, R57[1]
OUT4
MIXER
0dB / -6dB
Right
bypass
BYPR2OUT4, R57[2]
Left DAC
output
To
OUT4
output
stage
OUT4ATTN, R57[5]
LDAC2OUT4, R57[3]
Left mixer
output
LMIX2OUT4, R57[4]
Figure 38 OUT3 and OUT4 Mixers
OUT3 can provide a midrail reference, a left line output, or a mono mix line output
OUT4 can provide a midrail reference, a right line output, or a mono mix line output.
A 6dB attenuation function is provided for OUT4, to prevent clipping during mixing of left and right
signals. This function is enabled by the OUT4ATTN register bit.
74
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R1
Power
Management
1
7
OUT4MIXEN
0
OUT4 mixer enable
0=disabled
1=enabled
6
OUT3MIXEN
0
OUT3 mixer enable
0=disabled
1=enabled
R56
OUT3 mixer
control
6
OUT3MUTE
0
0 = Output stage outputs OUT3 mixer
1 = Output stage muted – drives out
VMID. Can be used as VMID reference
in this mode.
3
OUT4_2OUT3
0
OUT4 mixer output to OUT3
0 = disabled
1 = enabled
2
BYPL2OUT3
0
Left ADC input to OUT3
0 = disabled
1 = enabled
1
LMIX2OUT3
0
Left Output mixer to OUT3
0 = disabled
1= enabled
0
LDAC2OUT3
1
Left DAC output to OUT3
0 = disabled
1 = enabled
7
OUT3_2OUT4
0
OUT3 mixer output to OUT4
0 = disabled
1= enabled
6
OUT4MUTE
0
0 = Output stage outputs OUT4 mixer
1 = Output stage muted – drives out
VMID. Can be used as VMID reference
in this mode.
5
OUT4ATTN
0
0 = OUT4 normal output
1 = OUT4 attenuated by 6dB
4
LMIX2OUT4
0
Left Output mixer to OUT4
0 = disabled
1 = enabled
3
LDAC2OUT4
0
Left DAC to OUT4
0 = disabled
1 = enabled
2
BYPR2OUT4
0
Right ADC input to OUT4
0 = disabled
1 = enabled
1
RMIX2OUT4
0
Right Output mixer to OUT4
0 = disabled
1 = enabled
0
RDAC2OUT4
1
Right DAC output to OUT4
0 = disabled
1 = enabled
R57
OUT4 mixer
control
Table 47 OUT3/OUT4 Mixer Registers
The OUT3 and OUT4 output stages each have a selectable gain boost of 1.5x (3.52dB). When this
boost is enabled, the output DC level is also level shifted (from AVDD1/2 to 1.5xAVDD1/2) to prevent
the signal from clipping. A dedicated amplifier BUFDCOP, as shown in Figure 39, is used to perform
the DC level shift operation. This buffer must be enabled using the BUFDCOPEN register bit for this
operating mode. It should also be noted that if AVDD2 is not equal to or greater than 1.5xAVDD1, this
boost mode may result in signals clipping. Table 44 summarises the effect of the OUT3BOOST and
Rev 4.5
75
WM8983
OUT4BOOST control bits.
AVDD2
0dB or 3.52dB
From OUT4
mixer
OUT4
OUT3BOOST
R49[3]
OUT3BOOST
OUT4BOOST GAIN DC output
1x 1x(AVDD1/2)
0
1.5x 1.5x(AVDD1/2)
1
0dB or 3.52dB
From OUT3
mixer
OUT3
OUT4BOOST
R49[4]
AGND2
BUFDCOPEN
R1[8]
AVDD1/2
1.5xAVDD1/2
0.5R
+
-
Sets DC level on
output stages that
are configured for
1.5x gain boost.
R
Figure 39 Outputs OUT3 and OUT4
REGISTER
ADDRESS
R49
Output control
R1
Power
management
1
BIT
LABEL
DEFAULT
DESCRIPTION
3
OUT3BOOST
0
Output 3 Gain
0 = OUT3 output gain = -1;
DC = AVDD1 / 2
1 = OUT3 output gain = +1.5
DC = 1.5 x AVDD1 / 2
4
OUT4BOOST
0
Output 4 Gain
0 = OUT4 output gain = -1;
DC = AVDD1 / 2
1 = OUT4 output gain = +1.5
DC = 1.5 x AVDD1 / 2
8
BUFDCOPEN
Output stage 1.5xAVDD/2 driver
enable
0
0=Buffer disabled
1=Buffer enabled (required for 1.5x
gain boost)
Table 48 OUT3 and OUT4 Boost Stages Control
OUT3BOOST/
OUT4BOOST
OUTPUT
STAGE GAIN
OUTPUT DC
LEVEL
OUTPUT STAGE
CONFIGURATIO
N
0
1x
AVDD1/2
Inverting
1
1.5x
1.5xAVDD1/2
Non-inverting
Table 49 OUT3 and OUT4 Output Boost Stage Details
76
Rev 4.5
WM8983
OUTPUT PHASING
The relative phases of the analogue outputs will depend upon the following factors:
1.
DACLPOL and DACRPOL invert bits: Setting these bits to 1 will invert the DAC output.
2.
Mixer configuration: The polarity of the signal will depend upon the route through the mixer path.
For example, DACL can be directly input to the OUT3 mixer, giving a 180° phase shift at the
OUT3 mixer output. However, if DACL is input to the OUT3 mixer via the left mixer, an additional
phase shift will be introduced, giving 0° phase shift at the OUT3 mixer output.
3.
Output boost set-up: When 1.5x boost is enabled on an output, no phase shift occurs. When
1.5x boost is not enabled, a 180° phase shift occurs.
Figure 32 shows where these phase inversions can occur in the output signal path.
OUT4
Mixer
Boost
+
OUT4
Boost
+
AUX L
DAC
L
Left
Mixer
+
OUT3
OUT3
Mixer
LOUT1
Bypass L
AUX R
DAC
R
Right
Mixer
+
ROUT1
Bypass R
Boost
DACs have
programmable
invert option
LOUT2
Non-BTL
Boost
ROUT2
BTL
No phase inversion
Phase inversion
Phase depends on usage mode
BTL Mode
adds an
extra stage
of inversion
Output Boost
stages will
invert in 1x
mode, not in
1.5x mode
Figure 40 Output Signal Path Phasing
Rev 4.5
77
WM8983
Table 50 shows the polarities of the outputs in various configurations.
Unless otherwise stated, polarity is shown with respect to left DAC output in non-inverting mode.
Note that only registers relating to the mixer paths are shown here (Mixer enables, volume settings,
output enables etc are not shown).
0
0
DACs inverted
1
1
0
0
0
Stereo DAC playback
to LOUT1/ROUT1 and
LOUT2/ROUT2 and
OUT4/OUT3
(Speaker boost
enabled)
0
0
0
1
0
Stereo DAC playback
to LOUT1/ROUT1 and
LOUT2/ROUT2 and
OUT4/OUT3
(OUT3 and OUT4
boost enabled)
0
Stereo playback to
OUT3/OUT4 (DACs
input to OUT3/OUT4
mixers via left/right
mixers)
0
Differential output of
right bypass path via
OUT3/OUT4 (Phase
shown relative to right
bypass)
0
Differential output of
mono mix of DACs via
LOUT2/ROUT2 (e.g.
BTL speaker drive)
0
High power speaker
drive
0
0
0
0
0
0
0
1
1
0
0
0
1
0
0
0
0
ROUT2
PHASE / MAG
OUT4BOOST
0
1
LOUT2
PHASE / MAG
OUT3BOOST
0
0
ROUT1
PHASE / MAG
SPKBOOST
0
0
LOUT1
PHASE / MAG
INVROUT2
0
0
OUT3
PHASE / MAG
DACRPOL
Default:
Stereo DAC playback
to LOUT1/ROUT1,
LOUT2/ROUT2 and
OUT4/OUT3
MIXER PATH
REGISTERS
DIFFERENT
FROM DEFAULT
OUT4
PHASE / MAG
DACLPOL
CONFIGURATION
0°
0°
0°
0°
180°
180°
1
1
1
1
1
1
0
180°
180°
180°
180°
0°
0°
1
1
1
1
1
1
0
0°
0°
0°
0°
0°
0°
1
1
1
1
1.5
1.5
180°
180°
0°
0°
180°
180°
1.5
1.5
1
1
1
1
LDAC2OUT3=0
RDAC2OUT4=0
LMIX2OUT3=1
RMIX2OUT4=1
180°
180°
0°
0°
180°
180°
1
1
1
1
1
1
BYPR2OUT4=1
OUT4_2OUT3=1
180°
0°
X
X
X
X
1
1
0°
0°
0°
0°
180°
0°
1
1
1
1
1
1
0°
0°
0°
0°
0°
180°
1
1
1
1
1.5
1.5
1
0
0
0
0
Table 50 Relative Output Phases
Note that differential output should not be set up by combining outputs in boost mode with outputs
which are not in boost mode as this would cause a DC offset current on the outputs.
78
Rev 4.5
WM8983
ENABLING THE OUTPUTS
Each analogue output of the WM8983 can be independently enabled or disabled. The analogue mixer
associated with each output has a separate enable bit. All outputs are disabled by default. To save
power, unused parts of the WM8983 should remain disabled.
Outputs can be enabled at any time, but it is not recommended to do so when BUFIO is disabled
(BUFIOEN=0), as this may cause pop noise (see “Power Management” and “Applications Information”
sections).
REGISTER
ADDRESS
R1
Power
Management
1
R2
Power
Management
2
R3
Power
Management
3
Rev 4.5
BIT
LABEL
DEFAULT
DESCRIPTION
2
BUFIOEN
0
Unused input/output bias buffer enable
0=disabled
1=enabled
6
OUT3MIXEN
0
OUT3 mixer enable
0=disabled
1=enabled
7
OUT4MIXEN
0
OUT4 mixer enable
0=disabled
1=enabled
8
BUFDCOPEN
0
Output stage 1.5xAVDD/2 driver enable
0 = Buffer disabled
1 = Buffer enabled (required for 1.5x
gain boost)
8
ROUT1EN
0
ROUT1 output enable
0=disabled
1=enabled
7
LOUT1EN
0
LOUT1 output enable
0=disabled
1=enabled
6
SLEEP
0
Sleep Mode enable
0 = Normal device operation
1 = Supply current reduced in device
standby mode if clocks are still running
2
LMIXEN
0
Left output channel mixer enable
0 = disabled
1 = enabled
3
RMIXEN
0
Right output channel mixer enable
0 = disabled
1 = enabled
5
ROUT2EN
0
ROUT2 output enable
0 = disabled
1 = enabled
6
LOUT2EN
0
LOUT2 output enable
0 = disabled
1 = enabled
7
OUT3EN
0
OUT3 enable
0 = disabled
1 = enabled
8
OUT4EN
0
OUT4 enable
0 = disabled
1 = enabled
79
WM8983
R42
Output ctrl1
2
POBCTRL
0
Power-On Bias Control
(Use during power Up. Reset when
VMID bias is stable)
0 = Bias derived from VMID
1 = Bias derived from AVDD
1
DELEN
0
2nd enable bit for L/ROUT1
0
OUT1DEL
0
2 stage enable for L/ROUT1
Table 51 Output Stages Power Management Control
OUT1DEL enables lower pop noise power-up option for LOUT1 and ROUT1. See Recommended
Control Sequences (in 2 stage enable method, normal enable bit is set, followed shortly later by the
delayed enable DELEN).
THERMAL SHUTDOWN
To protect the WM8983 from overheating, a thermal shutdown circuit is included. If the device
temperature reaches approximately 1250C and the thermal shutdown circuit is enabled (TSDEN=1),
the L/ROUT2 amplifiers will be disabled. The thermal shutdown may also be configured to generate
an interrupt. See the GPIO and Interrupt Controller section for details.
REGISTER
ADDRESS
BIT
R49
Output Control
1
LABEL
DEFAULT
TSDEN
1
DESCRIPTION
Thermal Shutdown Enable
0 : thermal shutdown disabled
1 : thermal shutdown enabled
Table 52 Thermal Shutdown
UNUSED ANALOGUE INPUTS/OUTPUTS
Whenever an analogue input/output is disabled, it remains connected to a voltage source (either
AVDD1/2 or 1.5xAVDD1/2 as appropriate) through a resistor. This helps to prevent pop noise when
the output is re-enabled. The resistance between the voltage buffer and the output pins can be
controlled using the VROI control bit. The default impedance is low, so that any capacitors on the
outputs can charge up quickly at start-up. If a high impedance is desired for disabled outputs, VROI
can then be set to 1, increasing the resistance to about 30k.
A dedicated buffer is available for biasing unused analogue I/O pins as shown in Figure 41. This
buffer can be enabled using the BUFIOEN register bit.
If the SPKBOOST, OUT3BOOST or OUT4BOOST bits are set, then the relevant outputs will be tied to
the output of the DC level shift buffer at 1.5xAVDD/2 when disabled.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R1
Power
Management
1
2
BUFIOEN
0
Unused input/output bias buffer enable
0=disabled
1=enabled
R49
Output
Control
0
VROI
0
VREF (AVDD1/2 or 1.5xAVDD/2) to
analogue output resistance
0: approx 1k
1: approx 30 k
Table 53 Disabled Outputs to VREF Resistance
80
Rev 4.5
WM8983
Figure 41 summarises the bias options for the output pins.
1k
LOUT1
30k
VROI
R49[0]
1k
ROUT1
30k
AVDD1/2
+
VROI
R49[0]
AVDD1/2
BUFIOEN
R1[2]
1k
OUT4
Used to tie off all unused
inputs and outputs (except
those configured for 1.5x
gain boost).
30k
VROI
R49[0]
1k
OUT3
30k
VROI
R49[0]
1k
LOUT2
30k
VROI
R49[0]
1k
BUFDCOPEN
R1[8]
ROUT2
30k
1.5xAVDD1/2
0.5R
+
-
VROI
R49[0]
R
Used to set DC level on
output stages that are
configured for 1.5x gain
boost.
Figure 41 Unused Output Pin Tie-off Buffers
L/ROUT2EN/
OUT3/4EN
OUT3BOOST/
OUT4BOOST/
SPKBOOST
VROI
OUTPUT CONFIGURATION
0
0
0
1kΩ tie-off to AVDD1/2
0
0
1
30kΩ tie-off to AVDD1/2
0
1
0
1kΩ tie-off to 1.5xAVDD1/2
0
1
1
30kΩ tie-off to 1.5xAVDD1/2
1
0
X
Output enabled (DC level=AVDD1/2)
1
1
X
Output enabled (DC level=1.5xAVDD1/2)
Table 54 Unused Output Pin Bias Options
Rev 4.5
81
WM8983
DIGITAL AUDIO INTERFACES
The audio interface has four pins:




ADCDAT: ADC data output
DACDAT: DAC data input
LRC: Data Left/Right alignment clock
BCLK: Bit clock, for synchronisation
The clock signals BCLK, and LRC can be outputs when the WM8983 operates as a master, or inputs
when it is a slave (see Master and Slave Mode Operation, below).
Five different audio data formats are supported:





Left justified
Right justified
I2S
DSP mode early
DSP mode late
All of these modes are MSB first. They are described in Audio Data Formats, below. Refer to the
Electrical Characteristic section for timing information.
MASTER AND SLAVE MODE OPERATION
The WM8983 audio interface may be configured as either master or slave. As a master interface
device, the WM8983 generates BCLK and LRC and thus controls sequencing of the data transfer on
ADCDAT and DACDAT. To set the device to master mode, register bit MS should be set high. In
slave mode (MS=0), the WM8983 responds with data to clocks it receives over the digital audio
interfaces.
AUDIO DATA FORMATS
In Left Justified mode, the MSB is available on the first rising edge of BCLK following an LRC
transition. The other bits up to the LSB are then transmitted in order. Depending on word length,
BCLK frequency and sample rate, there may be unused BCLK cycles before each LRC transition.
1/fs
LEFT
CHANNEL
RIGHT
CHANNEL
LRC
BCLK
DACDAT /
ADCDAT
1
MSB
2
3
n-2 n-1
n
LSB
1
2
3
MSB
n-2 n-1
n
LSB
Figure 42 Left Justified Audio Interface (assuming n-bit word length)
In Right Justified mode, the LSB is available on the last rising edge of BCLK before a LRC transition.
All other bits are transmitted before (MSB first). Depending on word length, BCLK frequency and
sample rate, there may be unused BCLK cycles after each LRC transition.
82
Rev 4.5
WM8983
1/fs
LEFT
CHANNEL
RIGHT
CHANNEL
LCLK
BCLK
DACDAT /
ADCDAT
1
2
3
n-2 n-1
MSB
n
1
LSB
2
3
n-2 n-1
n
LSB
MSB
Figure 43 Right Justified Audio Interface (assuming n-bit word length)
In I2S mode, the MSB is available on the second rising edge of BCLK following a LRC transition. The
other bits up to the LSB are then transmitted in order. Depending on word length, BCLK frequency
and sample rate, there may be unused BCLK cycles between the LSB of one sample and the MSB of
the next.
1/fs
LEFT
CHANNEL
RIGHT
CHANNEL
LRC
BCLK
1 BCLK
1 BCLK
DACDAT
/ADCDAT
1
2
3
n-2 n-1
n
1
LSB
MSB
2
3
n-2 n-1
n
LSB
MSB
Figure 44 I2S Audio Interface (assuming n-bit word length)
In DSP/PCM mode, the left channel MSB is available on either the 1st (mode B) or 2nd (mode A) rising
edge of BCLK (selectable by LRP) following a rising edge of LRC. Right channel data immediately
follows left channel data. Depending on word length, BCLK frequency and sample rate, there may be
unused BCLK cycles between the LSB of the right channel data and the next sample.
In device master mode, the LRC output will resemble the LRC pulse shown in Figure 45 and Figure
46. In device slave mode, shown in Figure 47 and Figure 48, it is possible to use any length of LRC
pulse less than 1/fs, providing the falling edge of the LRC pulse occurs greater than one BCLK period
before the rising edge of the next LRC pulse.
1/fs
1 BCLK
LRCLK
BCLK
LEFT CHANNEL
DACDAT /
ADCDAT
1
2
3
RIGHT CHANNEL
n-2 n-1
MSB
n
1
2
3
n-2 n-1
n
LSB
Input Word Length (WL)
Figure 45 DSP/PCM Mode Audio Interface (mode A, LRP=0, Master)
Rev 4.5
83
WM8983
1/fs
1 BCLK
LRC
BCLK
RIGHT CHANNEL
LEFT CHANNEL
DACDAT /
ADCDAT
1
2
3
1
n
n-2 n-1
MSB
2
3
n-2 n-1
n
LSB
Input Word Length (WL)
Figure 46 DSP/PCM Mode Audio Interface (mode B, LRP=1, Master)
1/fs
1 BCLK
1 BCLK
LRCLK
falling edge can occur anywhere in this area
BCLK
LEFT CHANNEL
DACDAT /
ADCDAT
1
2
3
RIGHT CHANNEL
n-2 n-1
MSB
n
1
2
3
n-2 n-1
n
LSB
Input Word Length (WL)
Figure 47 DSP/PCM Mode Audio Interface (mode A, LRP=0, Slave)
1/fs
1 BCLK
1 BCLK
LRC
falling edge can occur anywhere in this area
BCLK
RIGHT CHANNEL
LEFT CHANNEL
DACDAT /
ADCDAT
1
2
3
n-2 n-1
MSB
n
1
2
3
n-2 n-1
n
LSB
Input Word Length (WL)
Figure 48 DSP/PCM Mode Audio Interface (mode B, LRP=0, Slave)
84
Rev 4.5
WM8983
REGISTER
ADDRESS
R4
Audio
Interface
Control
R5
BIT
LABEL
DEFAULT
DESCRIPTION
0
MONO
0
Selects between stereo and mono
device operation:
0 = Stereo device operation
1 = Mono device operation. Data
appears in ‘left’ phase of LRC.
1
ALRSWAP
0
Controls whether ADC data appears in
‘right’ or ‘left’ phases of LRC clock:
0=ADC left data appears in ‘left’ phase
of LRC and right data in 'right' phase
1=ADC left data appears in ‘right ’ phase
of LRC and right data in 'left' phase
2
DLRSWAP
0
Controls whether DAC data appears in
‘right’ or ‘left’ phases of LRC clock:
0=DAC left data appears in ‘left’ phase
of LRC and right data in 'right' phase
1=DAC left data appears in ‘right’ phase
of LRC and right data in 'left' phase
4:3
FMT
10
Audio interface Data Format Select:
00=Right Justified
01=Left Justified
10=I2S format
11= DSP/PCM mode
6:5
WL
10
Word length
00=16 bits
01=20 bits
10=24 bits
11=32 bits (see note)
7
LRP
0
LRC clock polarity
0=normal
1=inverted
8
BCP
0
BCLK polarity
0=normal
1=inverted
0
LOOPBACK
0
Digital loopback function
0=No loopback
1=Loopback enabled, ADC data output
is fed directly into DAC data input.
Table 55 Audio Interface Control
Note: Right Justified Mode will only operate with a maximum of 24 bits. If 32-bit mode is selected the
device will operate in 24-bit mode.
Rev 4.5
85
WM8983
AUDIO INTERFACE CONTROL
The register bits controlling audio format, word length and master / slave mode are summarised
below.
Register bit MS selects audio interface operation in master or slave mode. In Master mode, BCLK and
LRC are outputs. The frequencies of BCLK and LRC in master mode are controlled using MCLKDIV;
these clocks are divided down versions of PLL output clock (SYSCLK). The MCLKDIV default setting
provides a SYSCLK/256 division rate for the LRC output clock.
It is possible to divide down the BCLK rate using BCLKDIV; care must be taken in choosing the
correct BCLKDIV rate to maintain sufficient BCLK pulses per LRC period for the chosen data word
length. The BCLKDIV default setting provides a BCLK = SYSCLK clock.
REGISTER
ADDRESS
R6
Clock
Generation
Control
BIT
LABEL
DEFAULT
DESCRIPTION
0
MS
0
Sets the chip to be master over LRC and
BCLK
0=BCLK and LRC clock are inputs
(Slave mode)
1=BCLK and LRC clock are outputs
generated by the WM8983 (Master
mode)
4:2
BCLKDIV
000
Configures the BCLK and LRC output
frequency, for use when the chip is in
Master mode.
000=divide by 1 (BCLK=SYSCLK)
001=divide by 2 (BCLK=SYSCLK/2)
010=divide by 4
011=divide by 8
100=divide by 16
101=divide by 32
110=reserved
111=reserved
7:5
MCLKDIV
010
Sets the division for either the MCLK or
PLL clock output (selected by CLKSEL)
000=divide by 1
001=divide by 1.5
010=divide by 2
011=divide by 3
100=divide by 4
101=divide by 6
110=divide by 8
111=divide by 12
8
CLKSEL
1
Controls the source of the clock for all
internal operation:
0=MCLK
1=PLL output
Table 56 Clock Control
The CKLSEL bit selects the internal source of
MCLK (CLKSEL=0). When the internal clock
CLKSEL bit, the clock originally selected must
has changed for the switching of clocks to be
between the PLL and MCLK should be:
86
the Master clock from the PLL (CLKSEL=1) or from
is switched from one source to another using the
generate at least one falling edge after the CLKSEL
successful. For example the sequence for switching
1.
Change CLKSEL 1 -> 0
2.
Wait for at least one falling edge from PLL generated clock
3.
Disable the PLL (PLLEN=0)
Rev 4.5
WM8983
AUDIO SAMPLE RATES
The WM8983 filter characteristics for the ADCs and the DACs are set using the SR register bits; these
bits do not change the rate of the audio interface output clocks in Master mode. The cut-offs for the
digital filters and the ALC attack/decay times stated are determined using these values and assume a
256fs master clock rate.
If a sample rate is required which is not explicitly supported by the SR register settings, then the
closest SR value to that sample rate should be chosen, and the filter characteristics and ALC attack,
decay and hold times will scale appropriately.
REGISTER
ADDRESS
R7
Additional
Control
BIT
LABEL
3:1
SR
DEFAULT
000
DESCRIPTION
Approximate sample rate (configures the
coefficients for the internal digital filters):
000 = 48kHz
001 = 32kHz
010 = 24kHz
011 = 16kHz
100 = 12kHz
101 = 8kHz
110-111 = reserved
Table 57 Sample Rate Control
MASTER CLOCK AND PHASE LOCKED LOOP (PLL)
The WM8983 has an on-chip phase-locked loop (PLL) circuit that can be used to:

Generate master clocks for the WM8983 audio functions from another external clock, e.g. in
telecoms applications.

Generate and output (on pin CSB/GPIO1) a clock for another part of the system that is
derived from an existing audio master clock.
Figure 49 shows the PLL and internal clocking on the WM8983.
The PLL can be enabled or disabled by the PLLEN register bit.
REGISTER
ADDRESS
R1
Power
management 1
BIT
5
LABEL
PLLEN
DEFAULT
0
DESCRIPTION
PLL enable
0 = PLL off
1 = PLL on
Table 58 PLLEN Control Bit
Rev 4.5
87
WM8983
PLLPRESCALE
R36[4]
f1
MCLK
PLL1
R=f2/f1
f2
f/4
fPLLOUT
CLKSEL
R6[8]
f/2
ADC
SYSCLK
(256fs)
f/N
MCLKDIV
R6[7:5]
f/2
ADCOSR128
R14[3]
f/4
DAC
f/N
CSB/GPIO1
...
OPCLKDIV
R8[5:4]
f/2
DACOSR128
R10[3]
f/4
MS
R6[0]
LRC
MASTER
MODE
GPIOSEL
R8[2:1]
BCLKDIV
R6[4:2]
BCLK
MS
R6[0]
Figure 49 PLL and Clock Select Circuit
The PLL frequency ratio R = f2/f1 (see Figure 49) can be set using the register bits PLLK and PLLN.
R should be chosen to ensure 5 < PLLN < 13:

PLLN = int R

PLLK = int (224 (R-PLLN))
TO CALCULATE R:
There is a fixed divide by 4 in the PLL, f/4, and a selectable divide by N after the PLL, MCLKDIV.

f2 = SYSCLK x 4 x MCLKDIV

R = f2 / (MCLK / PRESCALE) = R

PLLN = int R

k = int ( 224 x (R – intR)) – convert k to hex for PLLK
EXAMPLE:
MCLK=26MHz, required clock = 12.288MHz.
R should be chosen to ensure 5 < PLLN < 13.
MCLKDIV = 2 sets the required division rate;

f2 = 4 x 2 x 12.288MHz = 98.304MHz.

R = 98.304 / (26/2) = 7.561846

PLLN = int R = 7

k = int ( 224 x (7.561846 – 7)) = 9426214dec
Convert k to hex:
PLLK = 8FD526h
Convert PLLK to R36, R37, R38 and R39 hex values:
R36 = 7h; R37 = 23h; R38 = 1EAh; R39 = 126h
88
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
R36
PLL N value
4
PLLPRESCALE
0
0 = MCLK input not divided (default)
1 = Divide MCLK by 2 before input
to PLL
3:0
PLLN
1000
Integer (N) part of PLL input/output
frequency ratio. Use values greater
than 5 and less than 13.
R37
PLL K value
1
5:0
PLLK [23:18]
0Ch
Fractional (K) part of PLL1
input/output frequency ratio (treat as
one 24-digit binary number).
R38
PLL K Value
2
8:0
PLLK [17:9]
093h
R39
PLL K Value
3
8:0
PLLK [8:0]
0E9h
LABEL
DEFAULT
DESCRIPTION
Table 59 PLL Frequency Ratio Control
The PLL performs best when f2 is around 90MHz. Its stability peaks at N=8. Some example settings
are shown in Table 60.
DESIRED
OUTPUT
(MHz)
F2
PRESCALE
(MHz)
DIVIDE
12
11.29
90.3168
1
2
7.5264
7
12
12.288
98.304
1
2
8.192
8
13
11.29
90.3168
1
2
6.947446
13
12.288
98.304
1
2
7.561846
14.4
11.29
90.3168
1
2
14.4
12.288
98.304
1
19.2
11.29
90.3168
2
19.2
12.288
98.304
19.68
11.29
19.68
12.288
19.8
19.8
24
24
26
26
27
27
MCLK
(MHz)
(F1)
MCLKDIV
R
PLLN
K
PLLK
PLLK
R36
(Hex)
[23:18]
[17:9]
[8:0]
R37 (Hex)
R38 (Hex)
R39 (Hex)
86C226
21
161
26
3126E8
C
93
E9
6
F28BD4
3C
145
1D4
7
8FD525
23
1EA
126
6.272
6
45A1CA
11
D0
1CA
2
6.826667
6
D3A06E
34
1D0
6D
2
9.408
9
6872AF
1A
39
B0
2
2
10.24
A
3D70A3
F
B8
A3
90.3168
2
2
9.178537
9
2DB492
B
DA
92
98.304
2
2
9.990243
9
FD809F
3F
C0
9F
11.29
90.3168
2
2
9.122909
9
1F76F7
7
1BB
F8
12.288
98.304
2
2
9.929697
9
EE009E
3B
100
9E
11.29
90.3168
2
2
7.5264
7
86C226
21
161
26
12.288
98.304
2
2
8.192
8
3126E8
C
93
E9
11.29
90.3168
2
2
6.947446
6
F28BD4
3C
145
1D4
12.288
98.304
2
2
7.561846
7
8FD525
23
1EA
126
11.29
90.3168
2
2
6.690133
6
BOAC93
2C
56
94
12.288
98.304
2
2
7.281778
7
482296
12
11
96
(Hex)
PLLK
Table 60 PLL Frequency Examples for Common MCLK Rates
LOOPBACK
Setting the LOOPBACK register bit enables digital loopback. When this bit is set, the output data
from the ADC audio interface is fed directly into the DAC data input.
See Table 55 for register definition.
Rev 4.5
89
WM8983
COMPANDING
The WM8983 supports A-law and -law companding on both transmit (ADC) and receive (DAC) sides.
Companding can be enabled on the DAC or ADC audio interfaces by writing the appropriate value to
the DAC_COMP or ADC_COMP register bits respectively.
REGISTER
ADDRESS
R5
Companding
Control
BIT
LABEL
DEFAULT
DESCRIPTION
2:1
ADC_COMP
0
ADC companding
00 = off
01 = reserved
10 = µ-law
11 = A-law
4:3
DAC_COMP
0
DAC companding
00 = off
01 = reserved
10 = µ-law
11 = A-law
5
WL8
0
0 = off
1 = device operates in 8-bit mode.
Table 61 Companding Control
Companding involves using a piecewise linear approximation of the following equations (as set out by
ITU-T G.711 standard) for data compression:
-law (where =255 for the U.S. and Japan):
F(x) = ln( 1 + |x|) / ln( 1 + )
-1 ≤ x ≤ 1
A-law (where A=87.6 for Europe):
F(x) = A|x| / ( 1 + lnA)
 for x ≤ 1/A
F(x) = ( 1 + lnA|x|) / (1 + lnA)
 for 1/A ≤ x ≤ 1
The companded data is also inverted as recommended by the G.711 standard (all 8 bits are inverted
for -law, all even data bits are inverted for A-law). The data will be transmitted as the first 8 MSB’s of
data.
Companding converts 13 bits (-law) or 12 bits (A-law) to 8 bits using non-linear quantization. The
input data range is separated into 8 levels, allowing low amplitude signals better precision than that of
high amplitude signals. This is to exploit the operation of the human auditory system, where louder
sounds do not require as much resolution as quieter sounds. The companded signal is an 8-bit word
containing sign (1-bit), exponent (3-bits) and mantissa (4-bits).
Setting the WL8 register bit allows the device to operate with 8-bit data. In this mode, it is possible to
use 8 BCLK’s per LRC frame. When using DSP mode B, this allows 8-bit data words to be output
consecutively every 8 BCLK’s and can be used with 8-bit data words using the A-law and u-law
companding functions.
BIT7
BIT[6:4]
BIT[3:0]
SIGN
EXPONENT
MANTISSA
Table 62 8-bit Companded Word Composition
90
Rev 4.5
WM8983
u-law Companding
1
120
0.9
Companded Output
0.7
80
0.6
0.5
60
0.4
40
0.3
Normalised Output
0.8
100
0.2
20
0.1
0
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Normalised Input
Figure 50 µ-Law Companding
A-law Companding
1
120
0.9
Companded Output
0.7
80
0.6
0.5
60
0.4
40
0.3
Normalised Output
0.8
100
0.2
20
0.1
0
0
0
0.2
0.4
0.6
0.8
1
Normalised Input
Figure 51 A-Law Companding
Rev 4.5
91
WM8983
GENERAL PURPOSE INPUT/OUTPUT
The WM8983 has three dual purpose input/output pins.

CSB/GPIO1: CSB / GPIO1 pin

L2/GPIO2: Left channel line input / headphone detection input

R2/GPIO3: Right channel line input / headphone detection input
The GPIO2 and GPIO3 functions are provided for use as jack detection inputs.
The GPIO1 and GPIO2 functions are provided for use as jack detection inputs or general purpose
outputs.
The default configuration for the CSB/GPIO1 is to be an input.
When setup as an input, the CSB/GPIO1 pin can either be used as CSB or for jack detection,
depending on how the MODE pin is set.
Table 63 illustrates the functionality of the GPIO1 pin when used as a general purpose output.
REGISTER
ADDRESS
R8
GPIO
Control
BIT
2:0
LABEL
GPIO1SEL
DEFAULT
000
DESCRIPTION
CSB/GPIO1 pin function select:
000= input (CSB/jack detection:
depending on MODE setting)
001 = reserved
010 = Temp ok
011 = Amute active
100 = PLL clk output
101 = PLL lock
110 = logic 0
111 = logic 1
3
GPIO1POL
0
GPIO1 Polarity invert
0 = Non inverted
1 = Inverted
5:4
OPCLKDIV
00
PLL Output clock division ratio
00 = divide by 1
01 = divide by 2
10 = divide by 3
11 = divide by 4
Table 63 CSB/GPIO Control
Note: If MODE is set to 3 wire mode, CSB/GPIO1 is used as CSB input irrespective of the
GPIO1SEL[2:0] bits.
For further details of the jack detect operation see the OUTPUT SWITCHING section.
92
Rev 4.5
WM8983
OUTPUT SWITCHING (JACK DETECT)
When the device is operated using a 2-wire interface, the CSB/GPIO1 pin can be used as a switch
control input to automatically disable one set of outputs and enable another; the most common use for
this functionality is as jack detect circuitry. The L2/GPIO2 and R2/GPIO3 pins can also be used for
this purpose.
The GPIO pins have an internal de-bounce circuit when in this mode in order to prevent the output
enables from toggling multiple times due to input glitches. This de-bounce circuit is clocked from a
slow clock with period 221 x MCLK and is enabled by the SLOWCLKEN bit.
Notes:
1.
The SLOWCLKEN bit must be enabled for the jack detect circuitry to operate.
2.
The GPIOPOL bit is not relevant for jack detection; it is the signal detected at the pin which is
used.
Switching on/off of the outputs is fully configurable by the user. Each output, OUT1, OUT2, OUT3 and
OUT4 has 2 associated enables. OUT1_EN_0, OUT2_EN_0, OUT3_EN_0 and OUT4_EN_0 are the
output enable signals which are used if the selected jack detection pin is at logic 0 (after de-bounce).
OUT1_EN_1, OUT2_EN_1, OUT3_EN_1 and OUT4_EN_1 are the output enable signals which are
used if the selected jack detection pin is at logic 1 (after de-bounce).
The jack detection enables operate as follows:
All OUT_EN signals have an AND function performed with their normal enable signals (in Table 51).
When an output is normally enabled at per Table 51, the selected jack detection enable (controlled by
selected jack detection pin polarity) is set 0; it will turn the output off. If the normal enable signal is
already OFF (0), the jack detection signal will have no effect due to the AND function.
During jack detection if the user desires an output to be un-changed whether the jack is in or not, both
the JD_EN settings, i.e. JD_EN0 and JD_EN1, should be set to 0000.
If jack detection is not enabled (JD_EN=0), the output enables default to all 1’s, allowing the outputs
to be controlled as normal via the normal output enables found in Table 51.
REGISTER
ADDRESS
R9 (09h)
GPIO control
R13 (0Dh)
Jack Detect
Control
BIT
LABEL
DEFAULT
DESCRIPTION
5:4
JD_SEL
00
Pin selected as jack detection input
00 = GPIO1
01 = GPIO2
10 = GPIO3
11 = Reserved
6
JD_EN
0
Jack Detection Enable
0 = disabled
1 = enabled
3:0
JD_EN0
0000
Output enables when selected jack
detection input is logic 0.
[0]= OUT1_EN_0
[1]= OUT2_EN_0
[2]= OUT3_EN_0
[3]= OUT4_EN_0
7:4
JD_EN1
0000
Output enables when selected jack
detection input is logic 1
[4]= OUT1_EN_1
[5]= OUT2_EN_1
[6]= OUT3_EN_1
[7]= OUT4_EN_1
Table 64 Jack Detect Register Control Bits
Rev 4.5
93
WM8983
CONTROL INTERFACE
SELECTION OF CONTROL MODE AND 2-WIRE MODE ADDRESS
The control interface can operate as either a 3-wire or 2-wire control interface. The MODE pin
determines the 2 or 3 wire mode as shown in Table 65.
The WM8983 is controlled by writing to registers through a serial control interface. A control word
consists of 16 bits. The first 7 bits (B15 to B9) are register address bits that select which control
register is accessed. The remaining 9 bits (B8 to B0) are data bits, corresponding to the 9 data bits in
each control register.
MODE
INTERFACE FORMAT
Low
2 wire
High
3 wire
Table 65 Control Interface Mode Selection
3-WIRE SERIAL CONTROL MODE
In 3-wire mode, every rising edge of SCLK clocks in one data bit from the SDIN pin. A rising edge on
CSB/GPIO latches in a complete control word consisting of the last 16 bits.
latch
CSB
SCLK
SDIN
B15
B14
B13
B12
B11
B10
control register address
B9
B8
B7
B6
B5
B4
B3
B2
B1
B0
control register data bits
Figure 52 3-Wire Serial Control Interface
2-WIRE SERIAL CONTROL MODE
The WM8983 supports software control via a 2-wire serial bus. Many devices can be controlled by the
same bus, and each device has a unique 7-bit device address (this is not the same as the 7-bit
address of each register in the WM8983).
The WM8983 operates as a slave device only. The controller indicates the start of data transfer with a
high to low transition on SDIN while SCLK remains high. This indicates that a device address and
data will follow. All devices on the 2-wire bus respond to the start condition and shift in the next eight
bits on SDIN (7-bit address + Read/Write bit, MSB first). If the device address received matches the
address of the WM8983, the WM8983 responds by pulling SDIN low on the next clock pulse (ACK). If
the address is not recognised or the R/W bit is ‘1’ when operating in write only mode, the WM8983
returns to the idle condition and waits for a new start condition and valid address.
During a write, once the WM8983 has acknowledged a correct address, the controller sends the first
byte of control data (B15 to B8, i.e. the WM8983 register address plus the first bit of register data).
The WM8983 then acknowledges the first data byte by driving SDIN low for one clock cycle. The
controller then sends the second byte of control data (B7 to B0, i.e. the remaining 8 bits of register
data), and the WM8983 acknowledges again by pulling SDIN low.
Transfer is complete when there is a low to high transition on SDIN while SCLK is high. After a
complete sequence, the WM8983 returns to the idle state and waits for another start condition. If a
start or stop condition is detected out of sequence at any point during data transfer (i.e. SDIN changes
while SCLK is high), the control interface returns to the idle condition.
94
Rev 4.5
WM8983
DEVICE ADDRESS
(7 BITS)
SDIN
RD / WR
BIT
ACK
(LOW)
CONTROL BYTE 1
(BITS 15 TO 8)
ACK
(LOW)
CONTROL BYTE 1
(BITS 7 TO 0)
ACK
(LOW)
SCLK
START
register address and
1st register data bit
remaining 8 bits of
register data
STOP
Figure 53 2-Wire Serial Control Interface
In 2-wire mode the WM8983 has a fixed device address, 0011010.
RESETTING THE CHIP
The WM8983 can be reset by performing a write of any value to the software reset register (address
0h). This will cause all register values to be reset to their default values. In addition to this there is a
Power-On Reset (POR) circuit which ensures that the registers are initially set to default when the
device is powered up.
POWER SUPPLIES
The WM8983 requires four separate power supplies:
AVDD1 and AGND1: Analogue supply, powers all internal analogue functions and output drivers
LOUT1 and ROUT1. AVDD1 must be between 2.5V and 3.6V and has the most significant impact on
overall power consumption (except for power consumed in the headphones). Higher AVDD1 will
improve audio quality.
AVDD2 and AGND2: Output driver supplies, power LOUT2, ROUT2, OUT3 and OUT4. AVDD2 must
be between 2.5V and 5.5V. AVDD2 can be tied to AVDD1, but it requires separate layout and
decoupling capacitors to curb harmonic distortion.
DCVDD: Digital core supply, powers all digital functions except the audio and control interfaces.
DCVDD must be between 1.71V and 3.6V, and has no effect on audio quality. The return path for
DCVDD is DGND, which is shared with DBVDD.
DBVDD must be between 1.71V and 3.6V. DBVDD return path is through DGND.
It is possible to use the same supply voltage for all four supplies. However, digital and analogue
supplies should be routed and decoupled separately on the PCB to keep digital switching noise out of
the analogue signal paths.
Rev 4.5
95
WM8983
POWER MANAGEMENT
SAVING POWER BY REDUCING OVERSAMPLING RATE
The default mode of operation of the ADC and DAC digital filters is in 64x oversampling mode. Under
the control of ADCOSR128 and DACOSR128, the oversampling rate may be doubled. 64x
oversampling results in a slight decrease in noise performance compared to 128x but lowers the
power consumption of the device.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R10
DAC control
3
DACOSR128
0
DAC oversample rate select
0 = 64x (lowest power)
1 = 128x (best performance)
R14
ADC control
3
ADCOSR128
0
ADC oversample rate select
0 = 64x (lowest power)
1 = 128x (best performance)
Table 66 ADC and DAC Oversampling Rate Selection
VMID
The analogue circuitry will not operate unless VMID is enabled. The impedance of the VMID resistor
string, together with the decoupling capacitor on the VMID pin will determine the start-up time of the
VMID circuit.
REGISTER
ADDRESS
R1
Power
management 1
BIT
1:0
LABEL
DEFAULT
VMIDSEL
00
DESCRIPTION
Reference string impedance to VMID pin
(Determines startup time):
00 = off (250kΩ VMID to AGND1)
01 = 100kΩ
10 = 500kΩ
11 = 10kΩ total (for fast start-up)
Table 67 VMID Impedance Control
BIASEN
The analogue amplifiers will not operate unless BIASEN is enabled.
REGISTER
ADDRESS
R1
Power
management 1
BIT
3
LABEL
BIASEN
DEFAULT
0
DESCRIPTION
Analogue amplifier bias control
0 = disabled
1 = enabled
Table 68 Analogue Bias Control
BIAS CONTROL
Control of the analog bias values is possible using BIASCUT.
REGISTER
ADDRESS
R61
Bias control
BIT
8
LABEL
BIASCUT
7:0
DEFAULT
DESCRIPTION
0
Global bias control
0 = normal
1 = 0.5x
000 0000
Reserved
Table 69 Analogue Bias Control
96
Rev 4.5
WM8983
REGISTER MAP
ADDR
B[15:9]
REGISTER
NAME
B8
B7
B6
B5
B4
B3
B2
B1
B0
DEF’T
VAL
D
E
C
H
E
X
0
00
Software Reset
1
01
Power manage’t
1
BUFDC
OPEN
OUT4
MIXEN
OUT3
MIXEN
PLLEN
MICBEN
BIASEN
BUFIO
EN
2
02
Power manage’t
2
ROUT1
EN
LOUT1
EN
SLEEP
BOOST
ENR
BOOST
ENL
INPPGA
ENR
INPPGA
ENL
ADC
ENR
ADC
ENL
000
3
03
Power manage’t
3
OUT4EN
OUT3EN
LOUT2
EN
ROUT2
EN
0
RMIXEN
LMIXEN
DAC
ENR
DAC
ENL
000
4
04
Audio Interface
BCP
LRP
DLR
SWAP
ALR
SWAP
MONO
050
5
05
Companding ctrl
0
0
LOOP
BACK
000
6
06
Clock Gen ctrl
CLKSEL
MS
140
7
07
Additional ctrl
0
0
0
SLOW
CLKEN
000
8
08
GPIO Control
0
0
0
OPCLKDIV[1:0]
GPIO1P
OL
9
09
Jack detect
control
0
0
JD_EN
JD_SEL[1:0]
0
0
0
0
000
10
0A
DAC Control
0
0
SOFT
MUTE
0
DAC
OSR128
AMUTE
DACR
POL
DACL
POL
000
11
0B
Left DAC digital
Vol
DACVU
DACLVOL[7:0]
0FF
12
0C
Right DAC dig’l
Vol
DACVU
DACRVOL[7:0]
0FF
13
0D
Jack Detect
Control
0
14
0E
ADC Control
HPFEN
15
0F
Left ADC Digital
Vol
ADCVU
ADCLVOL[7:0]
0FF
16
10
Right ADC Digital
Vol
ADCVU
ADCRVOL[7:0]
0FF
18
12
EQ1 – low shelf
EQ3D
MODE
0
EQ1C[1:0]
EQ1G[4:0]
12C
19
13
EQ2 – peak 1
EQ2BW
0
EQ2C[1:0]
EQ2G[4:0]
02C
20
14
EQ3 – peak 2
EQ3BW
0
EQ3C[1:0]
EQ3G[4:0]
02C
21
15
EQ4 – peak 3
EQ4BW
0
EQ4C[1:0]
EQ4G[4:0]
02C
22
16
EQ5 – high shelf
0
0
EQ5C[1:0]
EQ5G[4:0]
02C
24
18
DAC Limiter 1
LIMEN
25
19
DAC Limiter 2
0
0
27
1B
Notch Filter 1
NFU
NFEN
NFA0[13:7]
000
28
1C
Notch Filter 2
NFU
0
NFA0[6:0]
000
29
1D
Notch Filter 3
NFU
0
NFA1[13:7]
000
30
1E
Notch Filter 4
NFU
0
NFA1[6:0]
32
20
ALC control 1
33
21
ALC control 2
0
ALCHLD[3:0]
ALCLVL[3:0]
00B
34
22
ALC control 3
ALC
MODE
ALCDCY[3:0]
ALCATK[3:0]
032
35
23
Noise Gate
Rev 4.5
(HEX)
RESET
0
FMT[1:0]
WL8
DAC_COMP[1:0]
MCLKDIV[2:0]
HPFAPP
0
0
ADC
OSR128
LIMLVL[2:0]
0
ALCMAX[2:0]
0
GPIO1SEL[2:0]
0
0
ADCR
POL
000
ADC
LPOL
100
LIMATK[3:0]
032
LIMBOOST[3:0]
000
000
ALCMIN[2:0]
NGEN
000
000
JD_EN0[3:0]
HPFCUT[2:0]
0
0
SR[2:0]
LIMDCY[3:0]
0
ADC_COMP[1:0]
BCLKDIV[2:0]
0
JD_EN1[3:0]
ALCSEL
0
WL[1:0]
VMIDSEL[1:0]
NGTH[2:0]
038
000
97
WM8983
ADDR
B[15:9]
REGISTER
NAME
B8
B7
B6
B5
B4
B3
0
PLLPRE
SCALE
B2
B1
DEF’T
VAL
B0
D
E
C
H
E
X
36
24
PLL N
0
0
0
37
25
PLL K 1
0
0
0
38
26
PLL K 2
PLLK[17:9]
093
39
27
PLL K 3
PLLK[8:0]
0E9
41
29
3D control
42
2A
OUT4 to ADC
43
2B
Beep control
44
2C
45
(HEX)
0
0
PLLN[3:0]
008
PLLK[23:18]
0
OUT4_2ADCVOL[2:0]
00C
0
0
OUT4_2
LNR
0
0
POB
CTRL
DEPTH3D[3:0]
DELEN
OUT1
DEL
000
000
BYPL2
RMIX
BYPR2
LMIX
0
0
INV
ROUT2
0
0
0
0
000
Input ctrl
MBVSEL
0
R2_2
INPPGA
RIN2
INPPGA
RIP2
INPPGA
0
L2_2
INPPGA
LIN2
INPPGA
LIP2
INPPGA
033
2D
Left INP PGA
gain ctrl
INPGAVU
INPPGA
ZCL
INPPGA
MUTEL
INPPGAVOLL[5:0]
010
46
2E
Right INP PGA
gain ctrl
INPGAVU
INPPGA
ZCR
INPPGA
MUTER
INPPGAVOLR[5:0]
010
47
2F
Left ADC Boost
ctrl
PGA
BOOSTL
0
L2_2BOOSTVOL[2:0]
0
AUXL2BOOSTVOL[2:0]
100
48
30
Right ADC Boost
ctrl
PGA
BOOSTR
0
R2_2BOOSTVOL[2:0]
0
AUXR2BOOSTVOL[2:0]
100
49
31
Output ctrl
0
0
50
32
Left mixer ctrl
AUXLMIXVOL[2:0]
AUXL2
LMIX
51
33
Right mixer ctrl
AUXRMIXVOL[2:0]
AUXR2
RMIX
52
34
LOUT1 (HP)
volume ctrl
OUT1VU
LOUT1
ZC
LOUT1
MUTE
LOUT1VOL[5:0]
039
53
35
ROUT1 (HP)
volume ctrl
OUT1VU
ROUT1
ZC
ROUT1
MUTE
ROUT1VOL[5:0]
039
54
36
LOUT2 (SPK)
volume ctrl
OUT2VU
LOUT2
ZC
LOUT2
MUTE
LOUT2VOL[5:0]
039
55
37
ROUT2 (SPK)
volume ctrl
OUT2VU
ROUT2
ZC
ROUT2
MUTE
ROUT2VOL[5:0]
039
56
38
OUT3 mixer ctrl
0
0
OUT3
MUTE
0
0
OUT4_
2OUT3
BYPL2
OUT3
LMIX2
OUT3
LDAC2
OUT3
001
57
39
OUT4 (MONO)
mixer ctrl
0
OUT3_2
OUT4
OUT4
MUTE
OUT4
ATTN
LMIX2
OUT4
LDAC2
OUT4
BYPR2
OUT4
RMIX2
OUT4
RDAC2
OUT4
001
59
3B
ALC Test Mode
0
0
0
0
0
0
0
ALCTST[1:0]
000
61
3D
Bias Control
BIASCUT
0
0
0
0
0
0
0
000
DACL2
RMIX
DACR2
LMIX
OUT4
BOOST
OUT3
BOOST
SPK
BOOST
TSDEN
VROI
002
BYPLMIXVOL[2:0]
BYPL2
LMIX
DACL2
LMIX
001
BYPRMIXVOL[2:0]
BYPR2
RMIX
DACR2
RMIX
001
0
Table 70 WM8983 Register Map
98
Rev 4.5
WM8983
REGISTER BITS BY ADDRESS
Notes:
1. Default values of N/A indicate non-latched data bits (e.g. software reset or volume update bits).
2. Register bits marked "Reserved" should not be changed from the default.
REGISTER
ADDRESS
BIT
0 (00h)
[8:0]
RESET
N/A
Software reset
Resetting the
Chip
1 (01h)
8
BUFDCOPEN
0
Output stage 1.5xAVDD/2 driver enable
0 = Buffer disabled
1 = Buffer enabled (required for 1.5x gain boost)
Analogue
Outputs
7
OUT4MIXEN
0
OUT4 mixer enable
0=disabled
1=enabled
Power
Management
6
OUT3MIXEN
0
OUT3 mixer enable
0=disabled
1=enabled
Power
Management
5
PLLEN
0
PLL enable
0=PLL off
1=PLL on
Master Clock
and Phase
Locked Loop
(PLL)
4
MICBEN
0
Microphone Bias Enable
0 = OFF (high impedance output)
1 = ON
Input Signal
Path
3
BIASEN
0
Analogue amplifier bias control
0=disabled
1=enabled
Power
Management
2
BUFIOEN
0
Unused input/output tie off buffer enable
0=disabled
1=enabled
Power
Management
1:0
VMIDSEL
00
Reference string impedance to VMID pin
(Determines startup time):
00 = off (250kΩ VMID to AGND1)
01 = 100kΩ
10 = 500kΩ
11 = 10kΩ total (for fast start-up)
Power
Management
8
ROUT1EN
0
ROUT1 output enable
0=disabled
1=enabled
Power
Management
7
LOUT1EN
0
LOUT1 output enable
0=disabled
1=enabled
Power
Management
6
SLEEP
0
Sleep Mode enable
0 = normal device operation
1 = residual current reduced in device standby
mode
Power
Management
5
BOOSTENR
0
Right channel Input BOOST enable
0 = Boost stage OFF
1 = Boost stage ON
Power
Management
4
BOOSTENL
0
Left channel Input BOOST enable
0 = Boost stage OFF
1 = Boost stage ON
Power
Management
2 (02h)
Rev 4.5
LABEL
DEFAULT
DESCRIPTION
REFER TO
99
WM8983
REGISTER
ADDRESS
R3 (03h)
BIT
LABEL
100
DESCRIPTION
REFER TO
3
INPPGAENR
0
Right channel input PGA enable
0 = disabled
1 = enabled
Power
Management
2
INPPGAENL
0
Left channel input PGA enable
0 = disabled
1 = enabled
Power
Management
1
ADCENR
0
Enable ADC right channel:
0 = ADC disabled
1 = ADC enabled
Analogue to
Digital
Converter
(ADC)
0
ADCENL
0
Enable ADC left channel:
0 = ADC disabled
1 = ADC enabled
Analogue to
Digital
Converter
(ADC)
8
OUT4EN
0
OUT4 enable
0 = disabled
1 = enabled
Power
Management
7
OUT3EN
0
OUT3 enable
0 = disabled
1 = enabled
Power
Management
6
LOUT2EN
0
LOUT2 enable
0 = disabled
1 = enabled
Power
Management
5
ROUT2EN
0
ROUT2 enable
0 = disabled
1 = enabled
Power
Management
0
Reserved
Analogue
Outputs
4
4 (04h)
DEFAULT
3
RMIXEN
0
Right output channel mixer enable:
0 = disabled
1 = enabled
Analogue
Outputs
2
LMIXEN
0
Left output channel mixer enable:
0 = disabled
1 = enabled
Analogue
Outputs
1
DACENR
0
Right channel DAC enable
0 = DAC disabled
1 = DAC enabled
Analogue
Outputs
0
DACENL
0
Left channel DAC enable
0 = DAC disabled
1 = DAC enabled
Analogue
Outputs
8
BCP
0
BCLK polarity
0=normal
1=inverted
Digital Audio
Interfaces
7
LRP
0
LRC clock polarity
0=normal
1=inverted
Digital Audio
Interfaces
6:5
WL
10
Word length
00=16 bits
01=20 bits
10=24 bits
11=32 bits
Digital Audio
Interfaces
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
4:3
FMT
10
Audio interface Data Format Select:
00=Right Justified
01=Left Justified
10=I2S format
11= DSP/PCM mode
Digital Audio
Interfaces
2
DLRSWAP
0
Controls whether DAC data appears in ‘right’ or
‘left’ phases of LRC clock:
0=DAC data appears in ‘left’ phase of LRC
1=DAC data appears in ‘right’ phase of LRC
Digital Audio
Interfaces
1
ALRSWAP
0
Controls whether ADC data appears in ‘right’ or
‘left’ phases of LRC clock:
0=ADC data appears in ‘left’ phase of LRC
1=ADC data appears in ‘right’ phase of LRC
Digital Audio
Interfaces
0
MONO
0
Selects between stereo and mono device
operation:
Digital Audio
Interfaces
0=Stereo device operation
1=Mono device operation. Data appears in ‘left’
phase of LRC
5 (05h)
6 (06h)
8:6
000
Reserved
5
WL8
0
Companding Control 8-bit mode
0=off
1=device operates in 8-bit mode
Digital Audio
Interfaces
4:3
DAC_COMP
00
DAC companding
00=off
01=reserved
10=µ-law
11=A-law
Digital Audio
Interfaces
2:1
ADC_COMP
00
ADC companding
00=off
01=reserved
10=µ-law
11=A-law
Digital Audio
Interfaces
0
LOOPBACK
0
Digital loopback function
0=No loopback
1=Loopback enabled, ADC data output is fed
directly into DAC data input.
Digital Audio
Interfaces
8
CLKSEL
1
Controls the source of the clock for all internal
operation:
Digital Audio
Interfaces
0=MCLK
1=PLL output
7:5
Rev 4.5
MCLKDIV
010
Sets the scaling for either the MCLK or PLL
clock output (under control of CLKSEL)
000=divide by 1
001=divide by 1.5
010=divide by 2
011=divide by 3
100=divide by 4
101=divide by 6
110=divide by 8
111=divide by 12
Digital Audio
Interfaces
101
WM8983
REGISTER
ADDRESS
BIT
4:2
LABEL
BCLKDIV
1
7 (07h)
DEFAULT
DESCRIPTION
000
Configures the BCLK output frequency, for use
when the chip is in Master mode.
000=divide by 1 (BCLK= SYSCLK)
001=divide by 2 (BCLK= SYSCLK/2)
010=divide by 4
011=divide by 8
100=divide by 16
101=divide by 32
110=reserved
111=reserved
REFER TO
Digital Audio
Interfaces
0
Reserved
0
MS
0
Sets the chip to be master over LRC and BCLK
0=BCLK and LRC clock are inputs
1=BCLK and LRC clock are outputs generated
by the WM8983 (Master Mode)
Digital Audio
Interfaces
3:1
SR
000
Approximate sample rate (configures the
coefficients for the internal digital filters):
Audio Sample
Rates
000=48kHz
001=32kHz
010=24kHz
011=16kHz
100=12kHz
101=8kHz
110-111=reserved
0
SLOWCLKEN
0
Slow clock enable.
Used for both the jack insert detect debounce
circuit and the zero cross timeout.
Analogue
Outputs
0 = slow clock disabled
1 = slow clock enabled
8 (08h)
5:4
OPCLKDIV
00
PLL Output clock division ratio
00=divide by 1
01=divide by 2
10=divide by 3
11=divide by 4
General
Purpose
Input/Output
(GPIO)
3
GPIO1POL
0
GPIO1 Polarity invert
0=Non inverted
1=Inverted
General
Purpose
Input/Output
(GPIO)
2:0
GPIO1SEL
[2:0]
000
CSB/GPIO1 pin function select:
000= input (CSB/jack detection: depending on
MODE setting)
General
Purpose
Input/Output
(GPIO)
001= reserved
010=Temp ok
011=Amute active
100=PLL clk output
101=PLL lock
110=logic 0
111=logic 1
102
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
9 (09h)
8:7
LABEL
Rev 4.5
Reserved
0
Jack Detection Enable
0=disabled
1=enabled
Output
Switching
(Jack Detect)
5:4
JD_SEL
00
Pin selected as jack detection input
00 = GPIO1
01 = GPIO2
10 = GPIO3
11 = Reserved
Output
Switching
(Jack Detect)
0
Reserved
Output
Switching
(Jack Detect)
00
Reserved
0
Softmute enable:
0=Disabled
1=Enabled
8:7
SOFTMUTE
5:4
12 (0Ch)
00
REFER TO
JD_EN
6
11 (0Bh)
DESCRIPTION
6
3:0
10 (0Ah)
DEFAULT
Output Signal
Path
00
Reserved
3
DACOSR128
0
DAC oversample rate select
0 = 64x (lowest power)
1 = 128x (best performance)
Power
Management
2
AMUTE
0
Automute enable
0 = Amute disabled
1 = Amute enabled
Output Signal
Path
1
DACRPOL
0
Right DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
Output Signal
Path
0
DACLPOL
0
Left DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
Output Signal
Path
8
DACVU
N/A
DAC left and DAC right volume do not update
until a 1 is written to DACVU (in reg 11 or 12)
Digital to
Analogue
Converter
(DAC)
7:0
DACLVOL
11111111
Left DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
Digital to
Analogue
Converter
(DAC)
8
DACVU
N/A
DAC left and DAC right volume do not update
until a 1 is written to DACVU (in reg 11 or 12)
Output Signal
Path
7:0
DACRVOL
11111111
Right DAC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
Output Signal
Path
103
WM8983
REGISTER
ADDRESS
BIT
13 (0Dh)
8
14 (0Eh)
LABEL
16 (10h)
104
DESCRIPTION
REFER TO
0
Reserved
7:4
JD_EN1
0000
Output enabled when selected jack detection
input is logic 1
[4]= OUT1_EN_1
[5]= OUT2_EN_1
[6]= OUT3_EN_1
[7]= OUT4_EN_1
Output
Switching
(Jack Detect)
3:0
JD_EN0
0000
Output enabled when selected jack detection
input is logic 0.
Output
Switching
(Jack Detect)
[0]= OUT1_EN_0
[1]= OUT2_EN_0
[2]= OUT3_EN_0
[3]= OUT4_EN_0
High Pass Filter Enable
0=disabled
1=enabled
Analogue to
Digital
Converter
(ADC)
8
HPFEN
1
7
HPFAPP
0
Select audio mode or application mode
0=Audio mode (1st order, fc = ~3.7Hz)
1=Application mode (2nd order, fc = HPFCUT)
Analogue to
Digital
Converter
(ADC)
6:4
HPFCUT
000
Application mode cut-off frequency
See Table 16 for details
Analogue to
Digital
Converter
(ADC)
3
ADCOSR128
0
ADC oversample rate select
0 = 64x (lowest power)
1 = 128x (best performance)
Power
Management
2
15 (0Fh)
DEFAULT
0
Reserved
1
ADCRPOL
0
ADC right channel polarity adjust:
0=normal
1=inverted
Analogue to
Digital
Converter
(ADC)
0
ADCLPOL
0
ADC left channel polarity adjust:
0=normal
1=inverted
Analogue to
Digital
Converter
(ADC)
8
ADCVU
N/A
ADC left and ADC right volume do not update
until a 1 is written to ADCVU (in reg 16 or 17)
Analogue to
Digital
Converter
(ADC)
7:0
ADCLVOL
11111111
Left ADC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
Analogue to
Digital
Converter
(ADC)
8
ADCVU
N/A
ADC left and ADC right volume do not update
until a 1 is written to ADCVU (in reg 16 or 17)
Analogue to
Digital
Converter
(ADC)
7:0
ADCRVOL
11111111
Right ADC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -127dB
0000 0010 = -126.5dB
... 0.5dB steps up to
1111 1111 = 0dB
Analogue to
Digital
Converter
(ADC)
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
18 (12h)
8
LABEL
EQ3DMODE
7
19 (13h)
Rev 4.5
0 = Equaliser and 3D Enhancement applied to
ADC path
1 = Equaliser and 3D Enhancement applied to
DAC path
Output Signal
Path
0
Reserved
01
EQ Band 1 Cut-off Frequency:
00=80Hz
01=105Hz
10=135Hz
11=175Hz
Output Signal
Path
4:0
EQ1G
01100
EQ Band 1 Gain Control. See Table 38 for
details.
Output Signal
Path
8
EQ2BW
0
EQ Band 2 Bandwidth Control
0=narrow bandwidth
1=wide bandwidth
Output Signal
Path
0
Reserved
Output Signal
Path
6:5
EQ2C
01
EQ Band 2 Centre Frequency:
00=230Hz
01=300Hz
10=385Hz
11=500Hz
Output Signal
Path
4:0
EQ2G
01100
EQ Band 2 Gain Control. See Table 38 for
details.
Output Signal
Path
8
EQ3BW
0
EQ Band 3 Bandwidth Control
0=narrow bandwidth
1=wide bandwidth
Output Signal
Path
0
Reserved
Output Signal
Path
6:5
EQ3C
01
EQ Band 3 Centre Frequency:
00=650Hz
01=850Hz
10=1.1kHz
11=1.4kHz
Output Signal
Path
4:0
EQ3G
01100
EQ Band 3 Gain Control. See Table 38 for
details.
Output Signal
Path
8
EQ4BW
0
EQ Band 4 Bandwidth Control
0=narrow bandwidth
1=wide bandwidth
Output Signal
Path
0
Reserved
Output Signal
Path
7
22 (16h)
1
REFER TO
EQ1C
7
21 (15h)
DESCRIPTION
6:5
7
20 (14h)
DEFAULT
6:5
EQ4C
01
EQ Band 4 Centre Frequency:
00=1.8kHz
01=2.4kHz
10=3.2kHz
11=4.1kHz
Output Signal
Path
4:0
EQ4G
01100
EQ Band 4 Gain Control. See Table 38 for
details.
Output Signal
Path
0
Reserved
Output Signal
Path
8:7
6:5
EQ5C
01
EQ Band 5 Cut-off Frequency:
00=5.3kHz
01=6.9kHz
10=9kHz
11=11.7kHz
Output Signal
Path
4:0
EQ5G
01100
EQ Band 5 Gain Control. See Table 38 for
details.
Output Signal
Path
105
WM8983
REGISTER
ADDRESS
BIT
24 (18h)
8
LIMEN
0
7:4
LIMDCY
0011
3:0
LIMATK
25 (19h)
27 (1Bh)
106
LABEL
8:7
DEFAULT
DESCRIPTION
REFER TO
Enable the DAC digital limiter:
0=disabled
1=enabled
DAC Limiter Decay time (per 6dB gain change)
for 44.1kHz sampling. Note that these will scale
with sample rate:
0000=750us
0001=1.5ms
0010=3ms
0011=6ms
0100=12ms
0101=24ms
0110=48ms
0111=96ms
1000=192ms
1001=384ms
1010=768ms
Output Signal
Path
0010
DAC Limiter Attack time (per 6dB gain change)
for 44.1kHz sampling. Note that these will scale
with sample rate.
0000=94us
0001=188s
0010=375us
0011=750us
0100=1.5ms
0101=3ms
0110=6ms
0111=12ms
1000=24ms
1001=48ms
1010=96ms
1011 to 1111=192ms
Output Signal
Path
00
Reserved
Programmable signal threshold level
(determines level at which the DAC limiter starts
to operate)
000=-1dB
001=-2dB
010=-3dB
011=-4dB
100=-5dB
101 to 111=-6dB
DAC Limiter volume boost (can be used as a
stand alone volume boost when LIMEN=0):
0000 = 0dB
0001 = +1dB
0010 = +2dB
0011 = +3dB
0100 = +4dB
0101 = +5dB
0110 = +6dB
0111 = +7dB
1000 = +8dB
1001 = +9dB
1010 = +10dB
1011 = +11dB
1100 = +12dB
1101 to 1111 = reserved
Notch filter update. The notch filter values used
internally only update when one of the NFU bits
is set high.
6:4
LIMLVL
000
3:0
LIMBOOST
0000
8
NFU
0
Output Signal
Path
Output Signal
Path
Output Signal
Path
Analogue to
Digital
Converter
(ADC)
Rev 4.5
WM8983
REGISTER
ADDRESS
28 (1Ch)
BIT
LABEL
0
Notch filter enable:
0=Disabled
1=Enabled
Analogue to
Digital
Converter
(ADC)
6:0
NFA0[13:7]
0000000
Notch Filter a0 coefficient, bits [13:7]
Analogue to
Digital
Converter
(ADC)
8
NFU
0
Notch filter update. The notch filter values used
internally only update when one of the NFU bits
is set high.
Analogue to
Digital
Converter
(ADC)
0
Reserved
6:0
NFA0[6:0]
0000000
Notch Filter a0 coefficient, bits [6:0]
Analogue to
Digital
Converter
(ADC)
8
NFU
0
Notch filter update. The notch filter values used
internally only update when one of the NFU bits
is set high.
Analogue to
Digital
Converter
(ADC)
0
Reserved
6:0
NFA1[13:7]
0000000
Notch Filter a1 coefficient, bits [13:7]
Analogue to
Digital
Converter
(ADC)
8
NFU
0
Notch filter update. The notch filter values used
internally only update when one of the NFU bits
is set high.
Analogue to
Digital
Converter
(ADC)
7
32 (20h)
0
Reserved
6:0
NFA1[6:0]
0000000
Notch Filter a1 coefficient, bits [6:0]
Analogue to
Digital
Converter
(ADC)
8:7
ALCSEL
00
ALC function select:
00 = ALC disabled
01 = Right channel ALC enabled
10 = Left channel ALC enabled
11 = Both channels ALC enabled
Input Limiter/
Automatic
Level Control
(ALC)
0
Reserved
111
Set Maximum Gain of PGA
111=+35.25dB
110=+29.25dB
101=+23.25dB
100=+17.25dB
011=+11.25dB
010=+5.25dB
001=-0.75dB
000=-6.75dB
6
5:3
Rev 4.5
REFER TO
NFEN
7
30 (1Eh)
DESCRIPTION
7
7
29 (1Dh)
DEFAULT
ALCMAX
Input Limiter/
Automatic
Level Control
(ALC)
107
WM8983
REGISTER
ADDRESS
33 (21h)
34 (22h)
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
2:0
ALCMIN
000
Set minimum gain of PGA
000=-12dB
001=-6dB
010=0dB
011=+6dB
100=+12dB
101=+18dB
110=+24dB
111=+30dB
Input Limiter/
Automatic
Level Control
(ALC)
7:4
ALCHLD
0000
ALC hold time before gain is increased.
0000 = 0ms
0001 = 2.67ms
0010 = 5.33ms
0011 = 10.66ms
0100 = 21.32ms
0101 = 42.64ms
0110 = 85.28ms
0111 = 0.17s
1000 = 0.34s
1001 = 0.68s
1010 = 1.36s
1011 = 2.7s
1100 = 5.4s
1101 = 10.9s
1110 = 21.8 s
1111 = 43.7s
Input Limiter/
Automatic
Level Control
(ALC)
3:0
ALCLVL
1011
Input Limiter/
Automatic
Level Control
(ALC)
8
ALCMODE
0
ALC target – sets signal level at ADC input
1111 = -1.5dBFS
1110 = -1.5dBFS
1101 = -3dBFS
1100 = -4.5dBFS
1011 = -6dBFS
1010 = -7.5dBFS
1001 = -9dBFS
1000 = -10.5dBFS
0111 = -12dBFS
0110 = -13.5dBFS
0101 = -15dBFS
0100 = -16.5dBFS
0011 = -18dBFS
0010 = -19.5dBFS
0001 = -21dBFS
0000 = -22.5dBFS
Determines the ALC mode of operation:
0=ALC mode (Normal Operation)
1=Limiter mode
7:4
ALCDCY
[3:0]
0011
Decay (gain ramp-up) time
(ALCMODE ==0)
Input Limiter/
Automatic
Level Control
(ALC)
Per step
Per 6dB
90% of range
0000
410us
3.3ms
24ms
0001
820us
6.6ms
48ms
0010
1.64ms
13.1ms
192ms
Input Limiter/
Automatic
Level Control
(ALC)
… (time doubles with every step)
108
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
1010
or
higher
0011
420ms
3.36s
REFER TO
24.576s
Decay (gain ramp-up) time
(ALCMODE ==1)
Per step
Per 6dB
90% of range
0000
90.8us
726.4us
5.26ms
0001
181.6us
1.453ms
10.53ms
0010
363.2us
2.905ms
21.06ms
… (time doubles with every step)
1010
3:0
ALCATK
0010
93ms
744ms
5.39s
ALC attack (gain ramp-down) time
(ALCMODE == 0)
Per step
Per 6dB
90% of range
0000
104us
832us
6ms
0001
208us
1.664ms
12ms
0010
416us
3.328ms
24.1ms
Input Limiter/
Automatic
Level Control
(ALC)
… (time doubles with every step)
1010
or
higher
0010
106ms
852ms
6.18s
ALC attack (gain ramp-down) time
(ALCMODE == 1)
Per step
Per 6dB
90% of range
0000
22.7us
182.4us
1.31ms
0001
45.4us
363.2us
2.62ms
0010
90.8us
726.4us
5.26ms
… (time doubles with every step)
1010
35 (23h)
36 (24h)
37 (25h)
Rev 4.5
8:4
00000
Reserved
23.2ms
186ms
1.348s
3
NGEN
0
ALC Noise gate function enable
1 = enable
0 = disable
Input Limiter/
Automatic
Level Control
(ALC)
2:0
NGTH
000
ALC Noise gate threshold:
000 = -39dB
001 = -45dB
010 = -51dB
011 = -57dB
100 = -63dB
101 = -70dB
110 = -76dB
111 = -81dB
Input Limiter/
Automatic
Level Control
(ALC)
8:5
0000
Reserved
4
PLL
PRESCALE
0
0 = MCLK input not divided (default)
1 = Divide MCLK by 2 before input to PLL
Master Clock
and Phase
Locked Loop
(PLL)
3:0
PLLN[3:0]
1000
Integer (N) part of PLL input/output frequency
ratio. Use values greater than 5 and less than
13.
Master Clock
and Phase
Locked Loop
(PLL)
000
Reserved
8:6
109
WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
5:0
PLLK[23:18]
01100
Fractional (K) part of PLL1 input/output
frequency ratio (treat as one 24-digit binary
number).
Master Clock
and Phase
Locked Loop
(PLL)
38 (26h)
8:0
PLLK[17:9]
010010011
Fractional (K) part of PLL1 input/output
frequency ratio (treat as one 24-digit binary
number).
Master Clock
and Phase
Locked Loop
(PLL)
39 (27h)
8:0
PLLK[8:0]
011101001
Fractional (K) part of PLL1 input/output
frequency ratio (treat as one 24-digit binary
number).
Master Clock
and Phase
Locked Loop
(PLL)
41 (29h)
8:4
00000
Reserved
42 (2Ah)
3:0
DEPTH3D
0000
Stereo depth
0000 = Disabled
0001 = 6.67%
0010 = 13.3%
0011 = 20%
0100 = 26.7%
0101 = 33.3%
0110 = 40%
0111 = 46.6%
1000 = 53.3%
1001 = 60%
1010 = 66.7%
1011 = 73.3%
1100 = 80%
1101 = 86.7%
1110 = 93.3%
1111 = 100% (maximum 3D effect)
3D Stereo
Enhancement
8:6
OUT4_2ADCVOL
000
Controls the OUT4 to ADC input boost stage:
000 = Path disabled (disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
Analogue
Outputs
5
OUT4_2LNR
0
OUT4 to L or R ADC input
0 = Right ADC input
1 = Left ADC input
Analogue
Outputs
000
Reserved
0
Power-On Bias Control
(Use during power Up. Reset when VMID bias is
stable)
4:3
2
POBCTRL
0 = Bias derived from VMID
1 = Bias derived from AVDD
43 (2Bh)
110
1
DELEN
0
2nd enable bit for L/ROUT1
0
OUT1DEL
0
2 stage enable for L/ROUT1
8
BYPL2RMIX
0
Left bypass path (from the Left channel input
PGA stage) to right output mixer
0 = not selected
1 = selected
Analogue
Outputs
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
7
LABEL
BYPR2LMIX
6:5
4
INVROUT2
3:0
44 (2Ch)
8
MBVSEL
7
6
R2_2INPPGA
DEFAULT
DESCRIPTION
0
Right bypass path (from the right channel input
PGA stage) to Left output mixer
0 = not selected
1 = selected
00
Reserved
0
Invert ROUT2 output
0 = Not inverted
1 = Inverted
0000
Reserved
0
Microphone Bias Voltage Control
0 = 0.9 * AVDD1
1 = 0.65 * AVDD1
0
Reserved
0
Connect R2 pin to right channel input PGA
positive terminal.
REFER TO
Analogue
Outputs
Analogue
Outputs
Input Signal
Path
Input Signal
Path
0=R2 not connected to input PGA
1=R2 connected to input PGA amplifier positive
terminal (constant input impedance).
5
RIN2INPPGA
1
Connect RIN pin to right channel input PGA
negative terminal.
0=RIN not connected to input PGA
1=RIN connected to right channel input PGA
amplifier negative terminal.
Input Signal
Path
4
RIP2INPPGA
1
Connect RIP pin to right channel input PGA
amplifier positive terminal.
0 = RIP not connected to input PGA
1 = right channel input PGA amplifier positive
terminal connected to RIP (constant input
impedance)
Input Signal
Path
0
Reserved
0
Connect L2 pin to left channel input PGA
positive terminal.
3
2
L2_2INPPGA
Input Signal
Path
0=L2 not connected to input PGA
1=L2 connected to input PGA amplifier positive
terminal (constant input impedance).
45 (2Dh)
Rev 4.5
1
LIN2INPPGA
1
Connect LIN pin to left channel input PGA
negative terminal.
0=LIN not connected to input PGA
1=LIN connected to input PGA amplifier negative
terminal.
Input Signal
Path
0
LIP2INPPGA
1
Connect LIP pin to left channel input PGA
amplifier positive terminal.
0 = LIP not connected to input PGA
1 = input PGA amplifier positive terminal
connected to LIP (constant input impedance)
Input Signal
Path
8
INPPGAVU
N/A
INPPGA left and INPPGA right volume do not
update until a 1 is written to INPPGAVU (in reg
45 or 46)
Input Signal
Path
7
INPPGAZCL
0
Left channel input PGA zero cross enable:
0=Update gain when gain register changes
1=Update gain on 1st zero cross after gain
register write.
Input Signal
Path
6
INPPGAMUTEL
0
Mute control for left channel input PGA:
0=Input PGA not muted, normal operation
1=Input PGA muted (and disconnected from the
following input BOOST stage).
Input Signal
Path
111
WM8983
REGISTER
ADDRESS
46 (2Eh)
47 (2Fh)
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
5:0
INPPGAVOLL
010000
Left channel input PGA volume
000000 = -12dB
000001 = -11.25dB
.
010000 = 0dB
.
111111 = 35.25dB
Input Signal
Path
8
INPPGAVU
N/A
INPPGA left and INPPGA right volume do not
update until a 1 is written to INPPGAUPDATE (in
reg 45 or 46)
Input Signal
Path
7
INPPGAZCR
0
Right channel input PGA zero cross enable:
0=Update gain when gain register changes
1=Update gain on 1st zero cross after gain
register write.
Input Signal
Path
6
INPPGAMUTER
0
Mute control for right channel input PGA:
0=Input PGA not muted, normal operation
1=Input PGA muted (and disconnected from the
following input BOOST stage).
Input Signal
Path
5:0
INPPGAVOLR
010000
Right channel input PGA volume
000000 = -12dB
000001 = -11.25db
.
010000 = 0dB
.
111111 = +35.25dB
Input Signal
Path
8
PGABOOSTL
1
Boost enable for left channel input PGA:
0 = PGA output has +0dB gain through input
BOOST stage.
1 = PGA output has +20dB gain through input
BOOST stage.
Input Signal
Path
0
Reserved
000
Controls the L2 pin to the left channel input
boost stage:
000=Path disabled (disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
0
Reserved
000
Controls the auxiliary amplifier to the left channel
input boost stage:
7
6:4
L2_2BOOSTVOL
3
2:0
AUXL2BOOSTVOL
Input Signal
Path
Input Signal
Path
000=Path disabled (disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
112
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
48 (30h)
8
LABEL
PGABOOSTR
7
6:4
R2_2BOOSTVOL
3
2:0
AUXR2BOOSTVOL
DEFAULT
DESCRIPTION
1
Boost enable for right channel input PGA:
0 = PGA output has +0dB gain through input
BOOST stage.
1 = PGA output has +20dB gain through input
BOOST stage.
0
Reserved
000
Controls the R2 pin to the right channel input
boost stage:
000=Path disabled (disconnected)
001 = -12dB
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
0
Reserved
000
Controls the auxiliary amplifier to the right
channel input boost stage:
REFER TO
Input Signal
Path
Input Signal
Path
Input Signal
Path
000=Path disabled (disconnected)
001 = -12dB gain
010 = -9dB gain
011 = -6dB gain
100 = -3dB gain
101 = +0dB gain
110 = +3dB gain
111 = +6dB gain
49 (31h)
Rev 4.5
8:7
00
Reserved
6
DACL2RMIX
0
Left DAC output to right output mixer
0 = not selected
1 = selected
Analogue
Outputs
5
DACR2LMIX
0
Right DAC output to left output mixer
0 = not selected
1 = selected
Analogue
Outputs
3
OUT3BOOST
0
Output 3 Gain
0 = OUT3 output gain = -1;
DC = AVDD1 / 2
1 = OUT3 output gain = +1.5
DC = 1.5 x AVDD1 / 2
Analogue
Outputs
4
OUT4BOOST
0
Output 4 Gain
0 = OUT4 output gain = -1;
DC = AVDD1 / 2
1 = OUT4 output gain = +1.5
DC = 1.5 x AVDD1 / 2
Analogue
Outputs
2
SPKBOOST
0
Analogue
Outputs
1
TSDEN
1
Speaker Gain
0 = speaker gain = -1;
DC = AVDD1 / 2
1 = speaker gain = +1.5;
DC = 1.5 x AVDD1 / 2
Thermal Shutdown Enable
0 : thermal shutdown disabled
1 : thermal shutdown enabled
Analogue
Outputs
113
WM8983
REGISTER
ADDRESS
50 (32h)
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
0
VROI
0
VREF (AVDD/2 or 1.5xAVDD/2) to analogue
output resistance
0: approx 1k
1: approx 30 k
Analogue
Outputs
8:6
AUXLMIXVOL
000
Aux left channel input to left mixer volume
control:
Analogue
Outputs
000 = -15dB
001 = -12dB
…
101 = 0dB
110 = +3dB
111 = +6dB
5
AUXL2LMIX
0
Left Auxiliary input to left channel output mixer:
0 = not selected
1 = selected
Analogue
Outputs
4:2
BYPLMIXVOL
000
Left bypass volume control to output channel
mixer:
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
Analogue
Outputs
1
BYPL2LMIX
0
Left bypass path (from the left channel input
PGA stage) to left output mixer
Analogue
Outputs
0 = not selected
1 = selected
51 (33h)
0
DACL2LMIX
1
Left DAC output to left output mixer
0 = not selected
1 = selected
Analogue
Outputs
8:6
AUXRMIXVOL
000
Aux right channel input to right mixer volume
control:
Analogue
Outputs
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
5
AUXR2RMIX
0
Right Auxiliary input to right channel output
mixer:
Analogue
Outputs
0 = not selected
1 = selected
114
Rev 4.5
WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
4:2
BYPRMIXVOL
000
Right bypass volume control to output channel
mixer:
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
Analogue
Outputs
1
BYPR2RMIX
0
Right bypass path (from the right channel input
PGA stage) to right output mixer
Analogue
Outputs
0 = not selected
1 = selected
52 (34h)
53 (35h)
54 (36h)
Rev 4.5
0
DACR2RMIX
1
Right DAC output to right output mixer
0 = not selected
1 = selected
Analogue
Outputs
8
OUT1VU
N/A
LOUT1 and ROUT1 volumes do not update until
a 1 is written to OUT1VU (in reg 52 or 53)
Analogue
Outputs
7
LOUT1ZC
0
Headphone volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
Analogue
Outputs
6
LOUT1MUTE
0
Left headphone output mute:
0 = Normal operation
1 = Mute
Analogue
Outputs
5:0
LOUT1VOL
111001
Left headphone output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
Analogue
Outputs
8
OUT1VU
N/A
LOUT1 and ROUT1 volumes do not update until
a 1 is written to OUT1VU (in reg 52 or 53)
Analogue
Outputs
7
ROUT1ZC
0
Headphone volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
Analogue
Outputs
6
ROUT1MUTE
0
Right headphone output mute:
0 = Normal operation
1 = Mute
Analogue
Outputs
5:0
ROUT1VOL
111001
Right headphone output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
Analogue
Outputs
8
OUT2VU
N/A
LOUT2 and ROUT2 volumes do not update until
a 1 is written to OUT2VU (in reg 54 or 55)
Analogue
Outputs
7
LOUT2ZC
0
Left speaker volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
Analogue
Outputs
115
WM8983
REGISTER
ADDRESS
55 (37h)
56 (38h)
BIT
LABEL
REFER TO
LOUT2MUTE
0
Left speaker output mute:
0 = Normal operation
1 = Mute
Analogue
Outputs
5:0
LOUT2VOL
111001
Left speaker output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
Analogue
Outputs
8
OUT2VU
N/A
LOUT2 and ROUT2 volumes do not update until
a 1 is written to OUT2VU (in reg 54 or 55)
Analogue
Outputs
7
ROUT2ZC
0
Right speaker volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
Analogue
Outputs
6
ROUT2MUTE
0
Right speaker output mute:
0 = Normal operation
1 = Mute
Analogue
Outputs
5:0
ROUT2VOL
111001
Right speaker output volume:
000000 = -57dB
000001 = -56dB
...
111001 = 0dB
...
111111 = +6dB
Analogue
Outputs
00
Reserved
0
0 = Output stage outputs OUT3 mixer
1 = Output stage muted – drives out VMID. Can
be used as VMID buffer in this mode.
8:7
OUT3MUTE
5:4
116
DESCRIPTION
6
6
57 (39h)
DEFAULT
Analogue
Outputs
00
Reserved
3
OUT4_2OUT3
0
OUT4 mixer output to OUT3
0 = disabled
1= enabled
Analogue
Outputs
2
BYPL2OUT3
0
Left ADC input to OUT3
0 = disabled
1= enabled
Analogue
Outputs
1
LMIX2OUT3
0
Left Output mixer to OUT3
0 = disabled
1= enabled
Analogue
Outputs
0
LDAC2OUT3
1
Left DAC output to OUT3
0 = disabled
1= enabled
Analogue
Outputs
8
0
Reserved
7
OUT3_2OUT4
0
OUT3 mixer output to OUT4
0 = disabled
1 = enabled
Analogue
Outputs
6
OUT4MUTE
0
0 = Output stage outputs OUT4 mixer
1 = Output stage muted – drives out VMID. Can
be used as VMID buffer in this mode.
Analogue
Outputs
5
OUT4ATTN
0
0 = OUT4 normal output
1 = OUT4 attenuated by 6dB
Analogue
Outputs
Rev 4.5
WM8983
REGISTER
ADDRESS
59 (3Bh)
61 (3Dh)
BIT
DEFAULT
DESCRIPTION
REFER TO
4
LMIX2OUT4
0
Left Output mixer to OUT4
0 = disabled
1= enabled
Analogue
Outputs
3
LDAC2OUT4
0
Left DAC to OUT4
0 = disabled
1= enabled
Analogue
Outputs
2
BYPR2OUT4
0
Right ADC input to OUT4
0 = disabled
1= enabled
Analogue
Outputs
1
RMIX2OUT4
0
Right Output mixer to OUT4
0 = disabled
1= enabled
Analogue
Outputs
0
RDAC2OUT4
1
Right DAC output to OUT4
0 = disabled
1= enabled
Analogue
Outputs
8:2
0000000
Reserved
1:0
ALCTST
00
ALC Test Mode
00 = disabled
11 = enabled
ALC Test
Mode
8
BIASCUT
0
Global bias control
0 = normal
1 = 0.5x
Bias Control
00000000
Reserved
7:0
Rev 4.5
LABEL
117
WM8983
DIGITAL FILTER CHARACTERISTICS
PARAMETER
TEST CONDITIONS
MIN
+/- 0.025dB
0
TYP
MAX
UNIT
ADC Filter
Passband
-6dB
0.454fs
0.5fs
Passband Ripple
+/- 0.025
Stopband
Stopband Attenuation
dB
0.546fs
f > 0.546fs
-60
Group Delay
dB
21/fs
ADC High Pass Filter
High Pass Filter Corner
Frequency
-3dB
3.7
-0.5dB
10.4
-0.1dB
21.6
Hz
DAC Filter
Passband
+/- 0.035dB
0
-6dB
0.454fs
0.5fs
Passband Ripple
+/-0.035
Stopband
Stopband Attenuation
Group Delay
dB
0.546fs
f > 0.546fs
-55
dB
29/fs
Table 71 Digital Filter Characteristics
TERMINOLOGY
1.
Stop Band Attenuation (dB) – the degree to which the frequency spectrum is attenuated (outside audio band)
2.
Pass-band Ripple – any variation of the frequency response in the pass-band region
118
Rev 4.5
WM8983
DAC FILTER RESPONSES
3.05
0
3
-20
2.95
-40
Response (dB)
Response (dB)
20
-60
-80
2.9
2.85
2.8
2.75
-100
-120
2.7
-140
2.65
2.6
-160
0
0.5
1
1.5
2
0
2.5
0.05
0.1
0.15
Figure 54 DAC Digital Filter Frequency Response
(128xOSR)
0.25
0.3
0.35
0.4
0.45
0.5
0.45
0.5
Figure 55 DAC Digital Filter Ripple (128xOSR)
3.05
20
0
3
-20
2.95
-40
Response (dB)
Response (dB)
0.2
Frequency (fs)
Frequency (fs)
-60
-80
2.9
2.85
2.8
2.75
-100
-120
2.7
-140
2.65
2.6
-160
0
0.5
1
1.5
2
0
2.5
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
Frequency (fs)
Frequency (fs)
Figure 56 DAC Digital Filter Frequency Response (64xOSR)
Figure 57 DAC Digital Filter Ripple (64xOSR)
ADC FILTER RESPONSES
0.2
0
0.15
0.1
Response (dB)
Response (dB)
-20
-40
-60
-80
0.05
0
-0.05
-0.1
-100
-0.15
-0.2
-120
0
0.5
1
1.5
2
Frequency (Fs)
Figure 58 ADC Digital Filter Frequency Response
Rev 4.5
2.5
3
0
0.1
0.2
0.3
0.4
0.5
Frequency (Fs)
Figure 59 ADC Digital Filter Ripple
119
WM8983
HIGHPASS FILTER
The WM8983 has a selectable digital highpass filter in the ADC filter path. This filter has two modes,
audio and applications. In audio mode, the filter is a 1st order IIR with a cut-off of around 3.7Hz. In
applications mode, the filter is a 2nd order high pass filter with a selectable cut-off frequency.
5
0
-5
Response (dB)
-10
-15
-20
-25
-30
-35
-40
0
5
10
15
20
25
30
35
40
45
Frequency (Hz)
Figure 60 ADC Highpass Filter Response, HPFAPP=0
10
10
0
0
-10
-10
Response (dB)
Response (dB)
-20
-20
-30
-30
-40
-50
-40
-60
-50
-70
-80
-60
0
200
400
600
800
1000
1200
0
200
400
600
800
1000
1200
Frequency (Hz)
Frequency (Hz)
Figure 61 ADC Highpass Filter Responses (48kHz),
HPFAPP=1, all cut-off settings shown.
Figure 62 ADC Highpass Filter Responses (24kHz),
HPFAPP=1, all cut-off settings shown.
10
0
-10
Response (dB)
-20
-30
-40
-50
-60
-70
-80
-90
0
200
400
600
800
1000
1200
Frequency (Hz)
Figure 63 ADC Highpass Filter Responses (12kHz),
HPFAPP=1, all cut-off settings shown.
120
Rev 4.5
WM8983
5-BAND EQUALISER
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
The WM8983 has a 5-band equaliser which can be applied to either the ADC path or the DAC path.
The plots from Figure 64 to Figure 77 show the frequency responses of each filter with a sampling
frequency of 48kHz, firstly showing the different cut-off/centre frequencies with a gain of 12dB, and
secondly a sweep of the gain from -12dB to +12dB for the lowest cut-off/centre frequency of each
filter.
0
-5
-5
-10
-10
-15
-1
10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
-15
-1
10
5
10
Figure 64 EQ Band 1 Low Frequency Shelf Filter Cut-offs
15
15
10
10
5
5
0
-5
-10
-10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
Figure 66 EQ Band 2 – Peak Filter Centre Frequencies,
EQ2BW=0
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
0
-5
-15
-1
10
0
10
Figure 65 EQ Band 1 Gains for Lowest Cut-off Frequency
Magnitude (dB)
Magnitude (dB)
0
-15
-1
10
Figure 67
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
EQ Band 2 – Peak Filter Gains for Lowest
Cut-off Frequency, EQ2BW=0
15
10
Magnitude (dB)
5
0
-5
-10
-15
-2
10
-1
10
0
10
1
10
Frequency (Hz)
2
10
3
10
4
10
Figure 68 EQ Band 2 – EQ2BW=0, EQ2BW=1
Rev 4.5
121
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
WM8983
0
0
-5
-5
-10
-10
-15
-1
10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
Figure 69 EQ Band 3 – Peak Filter Centre Frequencies,
EQ3BW=0
-15
-1
10
Figure 70
0
10
1
10
2
10
Frequency (Hz)
3
10
4
5
10
10
EQ Band 3 – Peak Filter Gains for Lowest
Cut-off Frequency, EQ3BW=0
15
10
Magnitude (dB)
5
0
-5
-10
-15
-2
10
-1
10
0
10
1
10
Frequency (Hz)
2
10
3
10
4
10
Figure 71 EQ Band 3 – EQ3BW=0, EQ3BW=1
122
Rev 4.5
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
WM8983
0
0
-5
-5
-10
-10
-15
-1
10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
-15
-1
10
5
10
Figure 72 EQ Band 4 – Peak Filter Centre Frequencies,
EQ3BW=0
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
Figure 73 EQ Band 4 – Peak Filter Gains for Lowest
Cut-off Frequency, EQ4BW=0
15
10
Magnitude (dB)
5
0
-5
-10
-15
-2
10
-1
10
0
10
1
10
Frequency (Hz)
2
10
3
10
4
10
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
Figure 74 EQ Band 4 – EQ3BW=0, EQ3BW=1
0
0
-5
-5
-10
-10
-15
-1
10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
Figure 75 EQ Band 5 High Frequency Shelf Filter Cut-offs
Rev 4.5
-15
-1
10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
Figure 76 EQ Band 5 Gains for Lowest Cut-off Frequency
123
WM8983
Figure 77 shows the result of having the gain set on more than one channel simultaneously. The blue
traces show each band (lowest cut-off/centre frequency) with 12dB gain. The red traces show the
cumulative effect of all bands with +12dB gain and all bands -12dB gain, with EqxBW=0 for the peak
filters.
20
15
Magnitude (dB)
10
5
0
-5
-10
-15
-1
10
0
10
1
10
2
10
Frequency (Hz)
3
10
4
10
5
10
Figure 77 Cumulative Frequency Boost/Cut
124
Rev 4.5
WM8983
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
Figure 78 External Component Diagram
Rev 4.5
125
WM8983
PACKAGE DIAGRAM
FL: 32 PIN QFN PLASTIC PACKAGE 5 X 5 X 0.9 mm BODY, 0.50 mm LEAD PITCH
DM044.B
D
DETAIL 1
D2
32
25
L
1
24
4
EXPOSED
GROUND 6
PADDLE
A
INDEX AREA
(D/2 X E/2)
E2
17
E
8
2X
16
15
9
b
B
e
1
bbb M C A B
2X
aaa C
aaa C
TOP VIEW
BOTTOM VIEW
ccc C
A3
A
0.08 C
C
SEATING PLANE
5
SIDE VIEW
DETAIL 2
A3
R = 0.3MM x 45o
A1
EXPOSED
GROUND
PADDLE
DETAIL 1
G
b
Exposed lead
DETAIL 2
3.05
Dimensions (mm)
NOM
MAX
NOTE
0.85
0.90
0.02
0.05
0.203 REF
0.25
0.30
1
5.00 BSC
3.10
3.15
2
5.00 BSC
3.10
3.15
2
0.35
0.50 BSC
0.625
0.40
Symbols
A
A1
A3
b
D
D2
E
E2
e
G
L
aaa
bbb
ccc
REF:
MIN
0.80
0
0.20
3.05
0.45
Tolerances of Form and Position
0.15
0.10
0.10
JEDEC, MO-220, VARIATION VHHD-5.
NOTES:
1. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.15 mm AND 0.30 mm FROM TERMINAL TIP.
2. FALLS WITHIN JEDEC, MO-220, VARIATION VHHD-5.
3. ALL DIMENSIONS ARE IN MILLIMETRES.
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JEDEC 95-1 SPP-002.
5. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS .
6. REFER TO APPLICATION NOTE WAN_0118 FOR FURTHER INFORMATION REGARDING PCB FOOTPRINTS AND QFN PACKAGE SOLDERING.
7. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE.
126
Rev 4.5
WM8983
IMPORTANT NOTICE
Contacting Cirrus Logic Support
For all product questions and inquiries, contact a Cirrus Logic Sales Representative.
To find one nearest you, go to www.cirrus.com.
The products and services of Cirrus Logic International (UK) Limited; Cirrus Logic, Inc.; and other companies in the Cirrus Logic
group (“Cirrus”) are sold subject to Cirrus’s terms and conditions of sale supplied at the time of order acknowledgement, including
those pertaining to warranty, indemnification, and limitation of liability. Software is provided pursuant to applicable license terms.
Cirrus reserves the right to make changes to its products and specifications or to discontinue any product or service without notice.
Customers should therefore obtain the latest version of relevant information from Cirrus to verify that the information is current and
complete. Testing and other quality control techniques are utilized to the extent Cirrus deems necessary. Specific testing of all
parameters of each device is not necessarily performed. In order to minimize risks associated with customer applications, the
customer must use adequate design and operating safeguards to minimize inherent or procedural hazards. Cirrus is not liable for
applications assistance or customer product design. The customer is solely responsible for its selection and use of Cirrus products.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL
INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE
NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE IN PRODUCTS SURGICALLY IMPLANTED INTO THE BODY,
AUTOMOTIVE SAFETY OR SECURITY DEVICES, NUCLEAR SYSTEMS, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL
APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE
CUSTOMER’S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED,
INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH
REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER’S
CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY
SUCH USE, TO FULLY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER
AGENTS FROM ANY AND ALL LIABILITY, INCLUDING ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR
ARISE IN CONNECTION WITH THESE USES.
This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied, under any
patents, mask work rights, copyrights, trademarks, trade secrets or other intellectual property rights. Any provision or publication of
any third party’s products or services does not constitute Cirrus’s approval, license, warranty or endorsement thereof. Cirrus gives
consent for copies to be made of the information contained herein only for use within your organization with respect to Cirrus
integrated circuits or other products of Cirrus, and only if the reproduction is without alteration and is accompanied by all associated
copyright, proprietary and other notices and conditions (including this notice). This consent does not extend to other copying such as
copying for general distribution, advertising or promotional purposes, or for creating any work for resale. This document and its
information is provided “AS IS” without warranty of any kind (express or implied). All statutory warranties and conditions are
excluded to the fullest extent possible. No responsibility is assumed by Cirrus for the use of information herein, including use of this
information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third parties. Cirrus
Logic, Cirrus, the Cirrus Logic logo design and SoundClear are among the trademarks of Cirrus. Other brand and product names
may be trademarks or service marks of their respective owners.
Copyright © 2005–2015 Cirrus Logic, Inc. All rights reserved.
Rev 4.5
127
WM8983
REVISION HISTORY
DATE
REV
08/08/13
4.4
Delete AUXR > ROUT2 signal path.
Miscellaneous formatting updates.
PH
15/01/15
4.5
Selectable ROUT2 inversion (INVROUT2) added in Audio Paths Overview diagram
PH
128
DESCRIPTION OF CHANGES
CHANGED BY
Rev 4.5