WOLFSON WM8986GECO/RV

w
WM8986
Multimedia DAC With Class D Headphone and Line Out
DESCRIPTION
FEATURES
The WM8986 is a low power, high quality, feature-rich stereo
DAC designed for portable multimedia applications that require
low power consumption and high quality audio.
Stereo DAC:
•
DAC SNR 98dB, THD -86dB (‘A’ weighted @ 48kHz)
•
Headphone driver with ‘capless’ option
- 40mW/channel output power into 16Ω / 3.3V AVDD2
- Class D headphone driver
- Class AB headphone / line Driver
- PSRR 70dB at 217Hz
•
Stereo, mono or differential line output
The device integrates preamps for stereo differential mics, and
includes class D and class AB drivers for headphone and
differential or stereo line output. External component
requirements are reduced as no separate microphone or
headphone amplifiers are required.
Advanced DSP features include a 5-band equaliser and a digital
playback limiter. Highly flexible mixers enable many new
application features, with the option to playback any
combination of voice, line inputs and digital audio such as FM
Radio or MP3.
The WM8986 digital audio interface can operate in master or
slave mode, while an integrated PLL provides flexible clocking
schemes.
The WM8986 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. 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
Other Features:
•
Enhanced 3-D function for improved stereo separation
•
Digital playback limiter
•
5-band Equaliser
•
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
•
Low power, low voltage
•
2.5V to 3.6V analogue supplies
•
1.71V to 3.6V digital supplies
•
4x4mm 28-lead COL QFN package
APPLICATIONS
•
•
WOLFSON MICROELECTRONICS plc
To receive regular email updates, sign up at http://www.wolfsonmicro.com/enews/
Portable audio player / FM radio
Multimedia Mobile Handsets
Pre-Production, February 2007, Rev 3.1
Copyright ©2007 Wolfson Microelectronics plc
WM8986
Pre-Production
BLOCK DIAGRAM
w
PP, Rev 3.1, February 2007
2
WM8986
Pre-Production
TABLE OF CONTENTS
DESCRIPTION .......................................................................................................1
FEATURES.............................................................................................................1
APPLICATIONS .....................................................................................................1
BLOCK DIAGRAM .................................................................................................2
TABLE OF CONTENTS .........................................................................................3
PIN CONFIGURATION...........................................................................................4
ORDERING INFORMATION ..................................................................................4
PIN DESCRIPTION ................................................................................................5
ABSOLUTE MAXIMUM RATINGS.........................................................................6
RECOMMENDED OPERATING CONDITIONS .....................................................6
ELECTRICAL CHARACTERISTICS ......................................................................7
TERMINOLOGY .......................................................................................................... 11
AUDIO PATHS OVERVIEW .................................................................................12
SIGNAL TIMING REQUIREMENTS .....................................................................14
SYSTEM CLOCK TIMING ........................................................................................... 14
AUDIO INTERFACE TIMING – MASTER MODE ........................................................ 14
AUDIO INTERFACE TIMING – SLAVE MODE............................................................ 15
CONTROL INTERFACE TIMING – 3-WIRE MODE .................................................... 16
CONTROL INTERFACE TIMING – 2-WIRE MODE .................................................... 17
INTERNAL POWER ON RESET CIRCUIT ..........................................................18
RECOMMENDED POWER UP/DOWN SEQUENCE .................................................. 20
DEVICE DESCRIPTION.......................................................................................22
INTRODUCTION ......................................................................................................... 22
INPUT SIGNAL PATH ................................................................................................. 23
OUTPUT SIGNAL PATH ............................................................................................. 31
3D STEREO ENHANCEMENT .................................................................................... 37
ANALOGUE OUTPUTS............................................................................................... 37
DIGITAL AUDIO INTERFACES................................................................................... 50
AUDIO SAMPLE RATES ............................................................................................. 54
MASTER CLOCK AND PHASE LOCKED LOOP (PLL) ............................................... 55
COMPANDING............................................................................................................ 57
GENERAL PURPOSE INPUT/OUTPUT...................................................................... 59
OUTPUT SWITCHING (JACK DETECT)..................................................................... 60
CONTROL INTERFACE.............................................................................................. 61
RESETTING THE CHIP .............................................................................................. 62
POWER SUPPLIES .................................................................................................... 62
POWER MANAGEMENT ............................................................................................ 63
REGISTER MAP...................................................................................................64
REGISTER BITS BY ADDRESS ................................................................................. 66
DAC DIGITAL FILTER CHARACTERISTICS ......................................................79
TERMINOLOGY .......................................................................................................... 79
DAC FILTER RESPONSES......................................................................................... 80
5-BAND EQUALISER .................................................................................................. 81
APPLICATIONS INFORMATION .........................................................................85
RECOMMENDED EXTERNAL COMPONENTS .......................................................... 85
PACKAGE DIAGRAM ..........................................................................................86
IMPORTANT NOTICE ..........................................................................................87
ADDRESS: .................................................................................................................. 87
w
PP, Rev 3.1, February 2007
3
WM8986
Pre-Production
PIN CONFIGURATION
ORDERING INFORMATION
ORDER CODE
TEMPERATURE
RANGE
PACKAGE
MOISTURE
SENSITIVITY LEVEL
PEAK SOLDERING
TEMPERATURE
WM8986GECO/V
-25°C to +85°C
28-lead COL QFN (4 x 4 mm)
(Pb-free)
MSL3
260oC
WM8986GECO/RV
-25°C to +85°C
28-lead COL QFN (4 x 4 mm)
(Pb-free, tape and reel)
MSL3
260oC
Note:
Reel quantity = 3,500
w
PP, Rev 3.1, February 2007
4
WM8986
Pre-Production
PIN DESCRIPTION
PIN
NAME
TYPE
1
LIP
Analogue input
DESCRIPTION
2
LIN
Analogue input
Left MIC pre-amp negative input
3
RIP
Analogue input
Right MIC pre-amp positive input
4
RIN
Analogue input
5
DACDAT
Digital Input
6
LRC
Digital Input / Output
DAC sample rate clock
7
BCLK
Digital Input / Output
Digital audio bit clock
8
MCLK
Digital Input
9
DGND
Supply
Digital ground
10
DCVDD
Supply
Digital core logic supply
Left MIC pre-amp positive input
Right MIC pre-amp negative input
DAC digital audio data input
Master clock input
11
DBVDD
Supply
12
CSB/GPIO1
Digital Input / Output
13
SCLK
Digital Input
3-Wire control interface clock input / 2-wire control interface clock input
14
SDIN
Digital Input / Output
3-Wire control interface data input / 2-Wire control interface data input
15
MODE
Digital Input
16
AUXL
Analogue input
17
AUXR
Analogue input
18
OUT4
Analogue Output
Buffered midrail headphone pseudo-ground / right line output / mono mix
output
19
OUT3
Analogue Output
Buffered midrail headphone pseudo-ground or left line output
20
ROUT2
Analogue Output
Class D or class AB headphone output right
21
AGND2
Supply
22
LOUT2
Analogue Output
23
AVDD2
Supply
24
VMID
Reference
25
AGND1
Supply
26
ROUT1
Analogue Output
Class AB headphone or line output right
27
LOUT1
Analogue Output
Class AB headphone or line output left
28
AVDD1
Supply
w
Digital buffer (I/O) supply
3-Wire control interface chip Select / GPIO1 pin
Control interface selection
Left auxiliary input
Right auxiliary input
Analogue ground (ground reference for ROUT2/LOUT2 and OUT3/OUT4)
Class D or class AB headphone output left
Analogue supply (feeds output amplifiers ROUT2/LOUT2 and OUT3/OUT4)
Decoupling for DAC reference voltage
Analogue ground (ground reference for all input amplifiers, PLL, DAC, interna
bias circuits, output amplifiers LOUT1, ROUT1)
Analogue supply (feeds all input amplifiers, PLL, DAC, internal bias circuits,
output amplifiers LOUT1, ROUT1)
PP, Rev 3.1, February 2007
5
WM8986
Pre-Production
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.
Wolfson tests its package types according to IPC/JEDEC J-STD-020B 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
MIN
MAX
-0.3V
+4.5V
Voltage range digital inputs
DGND -0.3V
DBVDD +0.3V
Voltage range analogue inputs
AGND1 -0.3V
AVDD1 +0.3V
DBVDD, DCVDD, AVDD1, AVDD2 supply voltages
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 internally independent (i.e. not connected).
3.
Analogue supply voltages should not be less than digital supply voltages.
4.
DBVDD must be greater than or equal to DCVDD.
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
Digital supply range (Core)
DCVDD
1.711
3.6
V
Digital supply range (Buffer)
DBVDD
1.71
3.6
V
AVDD1, AVDD2
2.51
Analogue supply range
Ground
TEST
CONDITIONS
DGND, AGND1, AGND2
MIN
TYP
MAX
3.6
0
UNIT
V
V
Notes:
1.
Analogue supply voltages should not be less than digital supply voltages.
w
PP, Rev 3.1, February 2007
6
WM8986
Pre-Production
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)
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
0 to 20kHz
150
µV
LIN, RIN input resistance
INPPGAVOLL and
INPPGAVOLR = +35.25dB
1.6
kΩ
LIN, RIN input resistance
INPPGAVOLL and
INPPGAVOLR = 0dB
46
kΩ
LIN, RIN input resistance
INPPGAVOLL and
INPPGAVOLR = -12dB
71
kΩ
LIP, RIP input resistance
All gain settings
90
kΩ
Input PGA equivalent input noise
Input Capacitance
All analogue input pins
10
pF
Input PGA Programmable Gain
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
-12
+35.25
dB
Auxiliary Analogue Inputs (AUXL, AUXR)
Full-scale Input Signal Level 2
Input Resistance
Input Capacitance
Gain range from AUXL and AUXR
input to left and right input PGA
mixers
AUXLBOOSTVOL and
AUXRBOOSTVOL step size
w
AVDD/3.3
Vrms
Left Input boost and mixer
enabled, at +6dB
11
kΩ
Left Input boost and mixer
enabled, at 0dB gain
22
kΩ
Left Input boost and mixer
enabled, at -12dB gain
60
kΩ
Right Input boost, mixer
enabled, at +6dB gain
11
kΩ
Right Input boost, mixer
enabled, at 0dB gain
22
kΩ
Right Input boost, mixer
enabled, at -12dB gain
60
kΩ
10
All analogue Inputs
Gain adjusted by
pF
+6
-12
dB
AUXL2BOOSTVOL and
AUXR2BOOSTVOL
3
dB
PP, Rev 3.1, February 2007
7
WM8986
Pre-Production
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 left and right mixers into 10kΩ / 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
LOUT1VOL and
ROUTVOL = 0dB
AVDD1/3.3
Vrms
A-weighted
AVDD1=AVDD2=3.3V
100
A-weighted
AVDD1=AVDD2=2.5V
96
dB
22Hz to 20kHz
AVDD1=AVDD2=3.3V
95.5
dB
22Hz to 20kHz
AVDD1=AVDD2=2.5V
93.5
dB
0dBFS input
AVDD1=AVDD2=3.3V
-86
0dBFS input
AVDD1=AVDD2=2.5V
-86
0dBFS input
AVDD1=AVDD2=3.3V
-84
0dBFS input
AVDD1=AVDD2=2.5V
-84
dBFS
1kHz signal
100
dB
LOUT2VOL and
ROUT2VOL = 0dB
AVDD1/3.3
Vrms
A-weighted
AVDD1=AVDD2=3.3V
100
A-weighted
AVDD1=AVDD2=2.5V
96
dB
22Hz to 20kHz
AVDD1=AVDD2=3.3V
95.5
dB
22Hz to 20kHz
AVDD1=AVDD2=2.5V
93.5
dB
0dBFS input
AVDD1=AVDD2=3.3V
-84
0dBFS input
AVDD1=AVDD2=2.5V
-82
0dBFS input
AVDD1=AVDD2=3.3V
-82
0dBFS input
AVDD1=AVDD2=2.5V
-80
dBFS
1kHz input signal
100
dB
-90
-80
dB
dBFS
dBFS
-78
dBFS
DAC to L/R mixer into 10kΩ / 50pF load on L/ROUT2, class AB mode
LOUT2VOL, ROUT2VOL, 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
-90
-80
dB
dBFS
dBFS
-78
dBFS
DAC to OUT3 and OUT4 mixers to OUT3/OUT4 outputs into 10kΩ / 50pF load. DACVOLL and DACVOLR = 0dB
Full-scale output voltage
Signal to Noise Ratio 3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
w
AVDD2/3.3
SNR
Vrms
A-weighted
AVDD1=AVDD2=3.3V
100
-90
dB
22Hz to 22kHz
AVDD1=AVDD2=3.3V
96
THD
full-scale signal
AVDD1=AVDD2=3.3V
-84
-80
dBFS
THD+N
full-scale signal
AVDD1=AVDD2=3.3V
-82
-78
dBFS
full-scale signal
-80
dB
dBFS
PP, Rev 3.1, February 2007
8
WM8986
Pre-Production
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
AVDD1=AVDD2=2.5V
Channel Separation
6
1kHz signal
100
dB
DAC to left and right mixer into headphone (16Ω load on LOUT1 and ROUT1
LOUT1VOL, ROUT1VOL, DACLVOL and DACRVOL = 0dB
Full-scale output
Signal to Noise Ratio
3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
AVDD1/3.3
Vrms
A-weighted
100
dB
22Hz to 20kHz
95.5
dB
THD
Po = 20mW, RL=16Ω
-75
dB
THD+N
Po = 20mW, RL=16Ω
-75
dB
1kHz signal
100
dB
SNR
Channel Separation 6
DAC to left and right mixer into headphone (16Ω load) on LOUT2 and ROUT2, Class AB mode
LOUT2VOL, ROUT2VOL, DACLVOL and DACRVOL = 0dB
Full-scale output
Signal to Noise Ratio 3
Total Harmonic Distortion 4
AVDD1/3.3
SNR
THD
Channel Separation 6
A-weighted
97
22Hz to 20kHz
95.5
Po = 20mW, RL=16Ω
-79
1kHz signal
100
Vrms
-90
dB
-75
dB
dB
dB
DAC to left and right mixer into headphone load on LOUT2 and ROUT2, Class D mode, Lfilter = 33nH Cfilter = 220nf
LOUT2VOL, ROUT2VOL, DACLVOL and DACRVOL = 0dB
Full-scale output
L/ROUT2VOL = 0dB
AVDD1/3.3
Signal to Noise Ratio 3
SNR
A-weighted
Total Harmonic Distortion 4
THD
Po = 20mW, RL=16Ω
-79
1kHz signal
Channel Separation 6
80
-90
90
Vrms
dB
-70
dB
100
dB
PWM Rise Time
1.5
ns
PWM Fall Time
1.5
ns
DCLKDIV = 1000
1.4
MHz
RL = 16Ω, tPW = 20ns,
PO = 20mW
72
%
100mVpp ripple @217Hz
injected on AVDD2
70
dB
No analogue output signal
on either channel
0.5
mA
PWM Switching Frequency
Efficiency
Power Supply Rejection
Idle Current
PSRR
PGA outputs 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
Programmable Gain step size
Mute attenuation
w
Gain adjusted by
L/ROUT1VOL and
L/ROUT2VOL
-57
0
+6
dB
Monotonic
1
dB
1kHz, full scale signal
L/ROUT1MUTE = 1
L/ROUT2MUTE = 1
85
dB
PP, Rev 3.1, February 2007
9
WM8986
Pre-Production
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
AUXL and AUXR into on OUT3/OUT4 outputs on 10kΩ / 50pF load
INPPGAVOLL, INPPGAVOLR = 0dB
Full-scale output voltage, 0dB gain
Signal to Noise Ratio
3
Total Harmonic Distortion 4
A-weighted
AVDD1=AVDD2=3.3V
90
98
Vrms
-90
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
-84
full-scale signal
AVDD1=AVDD2=2.5V
-82
full-scale signal
AVDD1=AVDD2=3.3V
-82
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
THD
full-scale signal
AVDD1=AVDD2=3.3V
-87
-75
dBFS
THD+N
full-scale signal
AVDD1=AVDD2=3.3V
-85
-73
dBFS
1kHz full scale signal
100
dB
AVDD2/3.3
Vrms
THD
Total Harmonic Distortion + Noise 5
Channel Separation
AVDD2/3.3
SNR
THD+N
6
-80
dBFS
dBFS
-78
dBFS
LIN and RIN into input PGA into LOUT1 and ROUT1 into 16Ω / 50pF loads
BYPLMIXVOL, BYPRMIXVOL, LOUT1VOL and ROUT1VOL = 0dB
Full-scale output voltage, 0dB gain
Signal to Noise Ratio 3
SNR
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise
5
Channel separation 6
A-weighted
AVDD1=AVDD2=3.3V
90
LIN and RIN into input PGA into OUT3 and OUT4 into 10kΩ / 50pF loads
INPPGAVOLL, INPPGAVOLR = 0dB
Full-scale output voltage
Signal to Noise Ratio
3
Total Harmonic Distortion 4
Total Harmonic Distortion + Noise 5
Channel Separation 6
w
SNR
A-weighted
AVDD1=AVDD2=3.3V
100
dB
SNR
22Hz to 22kHz
AVDD1=AVDD2=3.3V
95.5
dB
THD
full-scale signal
AVDD1=AVDD2=3.3V
-87
dBFS
THD+N
full-scale signal
AVDD1=AVDD2=3.3V
-85
dBFS
1kHz signal
100
dB
PP, Rev 3.1, February 2007
10
WM8986
Pre-Production
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
Digital Input / Output
Input HIGH Level
VIH
Input LOW Level
VIL
Output HIGH Level
VOH
Output LOW Level
VOL
Input Capacitance
Input leakage
0.7×DBV
DD
V
0.3×DBVDD
IOL=1mA
0.9×DBV
DD
V
IOH-1mA
All digital pins
V
0.1xDBVDD
V
10
pF
11
pA
TERMINOLOGY
1.
2.
3.
4.
5.
6.
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.
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.
w
PP, Rev 3.1, February 2007
11
WM8986
Pre-Production
POWER CONSUMPTION
Typical power consumption for various scenarios is shown below.
DCVDD(V)
DCVDD(mA)
DBVDD(V)
DBVDD(mA)
AVDD1(V)
AVDD1(mA)
AVDD2(V)
AVDD2(mA)
Total (mW)
All measurements are made with quiescent signal.
1.8
1.8
1.8
3.3
3.6
0.002
0.002
0.002
0.006
0.008
1.8
3.3
3.3
3.3
3.6
0
0
0
0
0
2.5
3
3.3
3.3
3.6
0.01
0.011
0.012
0.011
0.012
2.5
3
3.3
3.3
3.6
0
0
0
0
0
0.03
0.04
0.04
0.06
0.07
Standby mode (Lowest Power)
1.8
1.8
1.8
3.3
3.6
0.002
0.002
0.002
0.006
0.008
1.8
3.3
3.3
3.3
3.6
0
0
0
0
0
2.5
3
3.3
3.3
3.6
0.117
0.138
0.149
0.149
0.157
2.5
3
3.3
3.3
3.6
0
0
0
0
0
0.30
0.42
0.50
0.51
0.59
DAC Playback 32Ω load
L/ROUT2 - Class AB Mode
fs=44.1kHz
1.8
1.8
3.3
3.6
3.336
3.336
7.182
8.098
1.8 0.003
3.3 0.0021
3.3 0.0021
3.6 0.025
2.5
3
3.3
3.6
2.238
2.728
3.025
3.325
2.5
3
3.3
3.6
0.28
0.35
0.39
0.44
12.31
15.24
34.98
42.80
Description
Off (Default Settings)
Table 1 Power Consumption
Contact Wolfson for more information on device power consumption.
w
PP, Rev 3.1, February 2007
12
Pre-Production
WM8986
AUDIO PATHS OVERVIEW
Figure 1 Audio Paths Overview
w
PP, Rev 3.1, February 2007
13
WM8986
Pre-Production
SIGNAL TIMING REQUIREMENTS
SYSTEM CLOCK TIMING
tMCLKL
MCLK
tMCLKH
tMCLKY
Figure 2 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
Figure 3 Digital Audio Data Timing – Master Mode (see Control Interface)
w
PP, Rev 3.1, February 2007
14
WM8986
Pre-Production
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
Audio Data Input Timing Information
LRC propagation delay from BCLK falling edge
tDL
DACDAT setup time to BCLK rising edge
tDST
10
ns
DACDAT hold time from BCLK rising edge
tDHT
10
ns
AUDIO INTERFACE TIMING – SLAVE MODE
Figure 4 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
Audio Data Input Timing Information
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
Note:
BCLK period should always be greater than or equal to MCLK period.
w
PP, Rev 3.1, February 2007
15
WM8986
Pre-Production
CONTROL INTERFACE TIMING – 3-WIRE MODE
3-wire mode is selected by connecting the MODE pin high.
Figure 5 Control Interface Timing – 3-Wire Serial Control Mode
Test Conditions
o
DCVDD = 1.8V, DBVDD = AVDD1 = AVDD2 = 3.3V, DGND = AGND1 = AGND2 = 0V, TA=+25 C, 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
tps
0
Pulse width of spikes that will be suppressed
w
ns
5
ns
PP, Rev 3.1, February 2007
16
WM8986
Pre-Production
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 6 Control Interface Timing – 2-Wire Serial Control Mode
Test Conditions
DCVDD=1.8V, DBVDD=AVDD1=AVDD2=3.3V, DGND=AGND1=AGND2=0V,
MCLK = 256fs, 24-bit data, unless otherwise stated.
TA=+25oC,
PARAMETER
SYMBOL
MIN
SCLK Low Pulse-Width
t1
1.3
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
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
Slave
TYP
Mode,
fs=48kHz,
MAX
UNIT
526
kHz
Program Register Input Information
SCLK Frequency
w
0
ns
600
0
ns
900
ns
5
ns
PP, Rev 3.1, February 2007
17
WM8986
Pre-Production
INTERNAL POWER ON RESET CIRCUIT
Figure 7 Internal Power on Reset Circuit Schematic
The WM8986 includes an internal Power-On-Reset Circuit, as shown in Figure 7, which is used to
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.
Figure 8 Typical Power up Sequence where AVDD1 is Powered before DCVDD
Figure 8 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 Vpord_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.
w
PP, Rev 3.1, February 2007
18
WM8986
Pre-Production
Figure 9 Typical Power up Sequence where DCVDD is Powered before AVDD1
Figure 9 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:
w
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 Vpora_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.
PP, Rev 3.1, February 2007
19
WM8986
Pre-Production
RECOMMENDED POWER UP/DOWN SEQUENCE
In order to minimise output pop and click noise, it is recommended that the WM8986 device is
powered up and down under control using the following sequences:
Power Up:
1.
Turn on external power supplies. Wait for supply voltage to settle.
2.
Set low analogue bias mode, BIASCUT = 1
3.
Enable thermal shutdown TSDEN = TSOPCTRL = 1
4.
Enable Internal bias BIASEN = 1.
5.
Mute all outputs and set PGAs to minimum gain, R52 to R57 = 0x140h.
6.
Enable VMID independent current bias, POBCTRL = 1.
7.
Enable required outputs, DACs and mixers.
8.
Enable VMID with required charge time e.g. VMIDSEL=01.
9.
Wait 10ms (based on register updates of 325µs)
10. Setup digital interface, input amplifiers, PLL, and DACs for desired operation.
11. Disable VMID independent current bias, POBCTRL = 0.
12. Wait 500ms
1
13. Unmute L/ROUT1 and set desired volume, e.g. for 0dB R52 and R53 = 0x139h.
14. Unmute L/ROUT2 and set desired volume, e.g. for 0dB R54 and R55 = 0x139h.
Power Down 2:
1.
Disable Thermal shutdown, TSDEN = TSOPCTRL = 0
2.
Disable VMIDSEL=00 and BIASEN=0
3.
Wait for VMID to discharge 3
4.
Power off registers R1, R2, R3 = 0x000h
5.
Remove external power supplies
Notes:
w
1.
Charging time constant is determined by impedance selected by VMIDSEL and the value of
decoupling capacitor connected to VMID pin.
2.
It is possible to interrupt the power down sequence and power up to VMID before the allocated
VMID discharge time. This is done by following the power-up sequence omitting steps 4 to 8.
3.
Discharge time constant is determined by the values of analogue output capacitors.
PP, Rev 3.1, February 2007
20
WM8986
Pre-Production
Figure 10 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
n/fs
DAC Group Delay
51/fs
n/fs
Table 3 Typical POR Operation (Typical Simulated Values)
Notes:
w
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
AVDD1 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 AVDD1 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.
PP, Rev 3.1, February 2007
21
WM8986
Pre-Production
DEVICE DESCRIPTION
INTRODUCTION
The WM8986 is a low power audio IC combining a high quality stereo audio DAC 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:
HI-FI DAC
The hi-fi DAC provides high quality audio playback suitable for all portable audio hi-fi type
applications, including MP3 players 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.
LINE INPUTS (AUXL, AUXR)
The inputs, AUXL and AUXR, can be used as a stereo line input (e.g. melody chip or FM radio) or as
an input for warning tones (or ‘beeps’) etc. These inputs can be summed into the output paths, along
with the microphone preamp outputs.
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).
Total gain through the microphone paths of up to +55.25dB can be selected.
AUDIO INTERFACES
The WM8986 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 WM8986 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.
w
PP, Rev 3.1, February 2007
22
WM8986
Pre-Production
CLOCKING SCHEMES
WM8986 offers the normal audio DAC clocking scheme operation, where 256fs MCLK is provided to
the DAC. A flexible clock divider allows the 256fs DAC clock to be generated from a range of input
clock frequencies, for example, 256fs, 384fs, 512fs and 768fs.
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 GPIO1 pin and used elsewhere in the system; available in 2-wire control
mode only.
POWER CONTROL
The design of the WM8986 has given much attention to power consumption without compromising
performance. The WM8986 operates at low analog and digital supply voltages, and includes the
ability to power off any unused parts of the circuitry under software control. It also includes standby
and power off modes.
INPUT SIGNAL PATH
The WM8986 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 output mixers. Each input path has three input pins which can be configured in a variety of ways
to accommodate single-ended, pseudo-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. An additional signal path exists from the output of the boost/mix stage into the output
left/right mixers.
MICROPHONE INPUTS
The WM8986 can accommodate a variety of microphone configurations including single ended and
pseudo-differential inputs. The inputs to the left differential input PGA are LIN and LIP. The inputs to
the right differential input PGA are RIN and RIP.
w
PP, Rev 3.1, February 2007
23
WM8986
Pre-Production
Figure 11 Microphone Input PGA Circuit
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.
GND
65k
MIC
680R
+
65k
VMID
INPUT
PGA
To
input
mixers
MICBIAS
Figure 12 Psuedo-Differential Microphone Configuration
w
PP, Rev 3.1, February 2007
24
WM8986
Pre-Production
680R
MICBIAS
65k
MIC
To
input
mixers
+
GND
VMID
INPUT
PGA
Figure 13 Single-ended Microphone Configuration
The input PGAs are enabled by the INPPGAENL and INPPGAENR register bits.
REGISTER
ADDRESS
BIT
R2 (02h)
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 4 Input PGA Enable Register Settings
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R44 (2Ch)
Input
Control
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.
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.
Table 5 Input PGA Control
w
PP, Rev 3.1, February 2007
25
WM8986
Pre-Production
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 is controlled by the register bits INPPGAVOLL[5:0] and
INPPGABVOLR[5:0]. These register bits also affect the LIP pin when LIP2INPPGA=1 and the RIP
pin when RIP2INPPGA=1.
BIT
LABEL
DEFAULT
DESCRIPTION
REGISTER
ADDRESS
R45 (20h)
Left channel
input PGA
volume
control
R46 (2Eh)
Right
channel
input PGA
volume
control
5:0
INPPGAVOLL
010000
(0dB)
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)
(See "Volume Updates" below)
5:0
INPPGAVOLR
010000
(0dB)
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)
(See "Volume Updates" below)
Table 6 Input PGA Volume Control
w
PP, Rev 3.1, February 2007
26
WM8986
Pre-Production
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 14.
Figure 14 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 15.
Figure 15 Click Noise During Volume Update
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 16.
w
PP, Rev 3.1, February 2007
27
WM8986
Pre-Production
Figure 16 Volume Update Using Zero Cross Detection
If there is a long period where no zero-crossing occurs, a timeout circuit in the WM8986 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 17.
Figure 17 Volume Update After Timeout
w
PP, Rev 3.1, February 2007
28
WM8986
Pre-Production
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.
The 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). 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 2 selectable inputs: the input microphone PGA output or the AUX amplifier output. These three
inputs can be mixed together and have individual gain boost/adjust as shown in Figure 18.
Figure 18 Input Boost Stage
w
PP, Rev 3.1, February 2007
29
WM8986
Pre-Production
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 (2Fh)
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 (30h)
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 7 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.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R47 (2Fh)
Left channel
Input BOOST
control
2:0
AUXL2BOOSTVOL
000
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 (30h)
Right channel
Input BOOST
control
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
Table 8 Input BOOST Stage Control
w
PP, Rev 3.1, February 2007
30
WM8986
Pre-Production
The BOOST stage is enabled under control of the BOOSTEN register bit.
REGISTER
ADDRESS
R2 (02h)
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 9 Input BOOST Enable Control
OUTPUT SIGNAL PATH
The WM8986 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 WM8986, irrespective of whether the
DACs are running or not.
The WM8986 DACs receive digital input data on the DACDAT pin. The digital filter block processes
the data to provide the following functions:
ƒ
Digital volume control
ƒ
Graphic equaliser and 3-D enhancement
ƒ
ƒ
A digital peak limiter.
Sigma-Delta Modulation
High performance sigma-delta audio DAC converts the digital data into an analogue signal.
Figure 19 DAC Digital Filter Path
The analogue outputs from the DACs can then be mixed with the various 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 line
outputs.
DIGITAL PLAYBACK (DAC) PATH
Digital data is passed to the WM8986 via the flexible audio interface and is then passed through a
variety of advanced digital filters as shown in Figure 19 to the hi-fi DACs. The DACs are enabled by
the DACENL/R register bits.
REGISTER
ADDRESS
R3 (03h)
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 10 DAC Enable Control
The WM8986 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.
w
PP, Rev 3.1, February 2007
31
WM8986
Pre-Production
REGISTER
ADDRESS
BIT
R10 (0Ah)
DAC Control
LABEL
DEFAULT
DESCRIPTION
0
DACPOL
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 11 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.
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 (0Bh)
Left DAC
Digital Volume
R12 (0Ch)
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 12 DAC Digital Volume Control
w
PP, Rev 3.1, February 2007
32
WM8986
Pre-Production
Note: An additional gain of up to 12dB can be added using the gain block embedded in the
digital peak limiter circuit (see DAC 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 is described in the 5-BAND EQUALISER section.
3-D ENHANCEMENT
The WM8986 has an advanced digital 3-D enhancement feature which can be used to vary the
perceived stereo separation of the left and right channels.
Refer to the 3-D STEREO
ENHANCEMENT section for further details on this feature.
DAC DIGITAL OUTPUT LIMITER
The WM8986 has a digital output limiter function. The operation of this is shown in Figure 20. In this
diagram the upper graph shows the envelope of the input/output signals and the lower graph shows
the gain characteristic.
Figure 20 DAC Digital Limiter Operation
The limiter has a programmable upper threshold which is close to 0dB. Referring to Figure 20, 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.
w
PP, Rev 3.1, February 2007
33
WM8986
Pre-Production
REGISTER
ADDRESS
R24 (18h)
DAC digital
limiter control
1
BIT
3:0
LABEL
LIMATK
DEFAULT
0010
DESCRIPTION
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
7:4
LIMDCY
0011
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
R25 (19h)
DAC digital
limiter control
2
8
LIMEN
0
Enable the DAC digital limiter:
0=disabled
1=enabled
3:0
LIMBOOST
0000
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
w
PP, Rev 3.1, February 2007
34
WM8986
Pre-Production
REGISTER
ADDRESS
BIT
6:4
LABEL
LIMLVL
DEFAULT
000
DESCRIPTION
Programmable signal threshold level
(determines level at which the limiter
starts to operate)
000 = -1dB
001 = -2dB
010 = -3dB
011 = -4dB
100 = -5dB
101 to 111 = -6dB
Table 13 DAC Digital Limiter Control
5-BAND GRAPHIC EQUALISER
A 5-band graphic equaliser is provided, which can be applied to the DAC path, together with 3D
enhancement, under control of the EQ3DEN register bit.
REGISTER
ADDRESS
R18 (12h)
EQ Control 1
BIT
8
LABEL
EQ3DEN
DEFAULT
1
DESCRIPTION
0 = Equaliser and 3D Enhancement
disabled
1 = Equaliser and 3D Enhancement
enabled
Table 14 EQ and 3D Enhancement enable
Note: The DACs must be disabled before changing the EQ3DEN bit.
A 5-band graphic 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 (12h)
EQ Band 1
Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ1G
01100
(0dB)
Band 1 Gain Control. See Table 20 for
details.
6:5
EQ1C
01
Band 1 Cut-off Frequency:
00 = 80Hz
01 = 105Hz
10 = 135Hz
11 = 175Hz
Table 15 EQ Band 1 Control
REGISTER
ADDRESS
R19 (13h)
EQ Band 2
Control
BIT
LABEL
DEFAULT
4:0
EQ2G
01100
(0dB)
6:5
EQ2C
01
DESCRIPTION
Band 2 Gain Control. See Table 20 for
details.
Band 2 Centre Frequency:
00 = 230Hz
8
EQ2BW
0
01 = 300Hz
10 = 385Hz
11 = 500Hz
Band 2 Bandwidth Control
0 = narrow bandwidth
1 = wide bandwidth
Table 16 EQ Band 2 Control
w
PP, Rev 3.1, February 2007
35
WM8986
Pre-Production
REGISTER
ADDRESS
R20 (14h)
EQ Band 3
Control
BIT
LABEL
DEFAULT
4:0
EQ3G
01100
(0dB)
6:5
EQ3C
01
DESCRIPTION
Band 3 Gain Control. See Table 20 for
details.
Band 3 Centre Frequency:
00 = 650Hz
01 = 850Hz
8
EQ3BW
10 = 1.1kHz
11 = 1.4kHz
Band 3 Bandwidth Control
0 = narrow bandwidth
1 = wide bandwidth
0
Table 17 EQ Band 3 Control
REGISTER
ADDRESS
R21 (15h)
EQ Band 4
Control
BIT
LABEL
DEFAULT
4:0
EQ4G
01100
(0dB)
6:5
EQ4C
01
DESCRIPTION
Band 4 Gain Control. See Table 20 for
details
Band 4 Centre Frequency:
00 = 1.8kHz
01 = 2.4kHz
8
EQ4BW
10 = 3.2kHz
11 = 4.1kHz
Band 4 Bandwidth Control
0 = narrow bandwidth
1 = wide bandwidth
0
Table 18 EQ Band 4 Control
REGISTER
ADDRESS
R22 (16h)
EQ Band 5
Gain Control
BIT
LABEL
DEFAULT
DESCRIPTION
4:0
EQ5G
01100
(0dB)
Band 5 Gain Control. See Table 20 for
details.
6:5
EQ5C
01
Band 5 Cut-off Frequency:
00 = 5.3kHz
01 = 6.9kHz
10 = 9kHz
11 = 11.7kHz
Table 19 EQ Band 5 Control
GAIN REGISTER
GAIN
00000
+12dB
00001
+11dB
00010
+10dB
…. (1dB steps)
01100
0dB
01101
-1dB
11000
-12dB
11001 to 11111
Reserved
Table 20 Gain Register Table
See also Figure 40 to Figure 53 for equaliser and high pass filter responses.
w
PP, Rev 3.1, February 2007
36
WM8986
Pre-Production
3D STEREO ENHANCEMENT
The WM8986 has a digital 3D enhancement option to increase the perceived separation between the
left and right channels. The DEPTH3D setting controls the degree of stereo expansion.
REGISTER
ADDRESS
R41 (29h)
3D Control
BIT
3:0
LABEL
DEPTH3D
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 21 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 WM8986 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 class D or class AB headphone
drivers.
•
OUT3 and OUT4 – can be configured as a stereo line out (OUT3 is left output and
OUT4 is right output) or a differential output. OUT4 can also be used to provide a
mono mix of left and right channels.
The outputs LOUT2 and ROUT2 are powered from AVDD2 and are capable of driving a 1V rms
signal (AVDD1/3.3).
LOUT1, ROUT1, OUT3 and OUT4 are powered from AVDD1
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.
LEFT AND RIGHT OUTPUT CHANNEL MIXERS
The left and right output channel mixers are shown in Figure 21. These mixers allow the analogue
inputs 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 PGAs.
The AUX and PGA path 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
both the headphone (LOUT1 and ROUT1) and class D headphone (LOUT2 and ROUT2) and can
optionally be connected to the OUT3 and OUT4 mixers.
w
PP, Rev 3.1, February 2007
37
WM8986
Pre-Production
Figure 21 Left/Right Output Channel Mixers
w
PP, Rev 3.1, February 2007
38
WM8986
Pre-Production
REGISTER
ADDRESS
LABEL
DEFAULT
DESCRIPTION
R43 (2Bh)
Output mixer
control
8
BYPL2RMIX
0
Left channel input PGA stage to
right output mixer
0 = not selected
1 = selected
R43 (2Bh)
Output mixer
control
7
BYPR2LMIX
0
Right channel input PGA stage to
Left output mixer
0 = not selected
1 = selected
R49 (31h)
Output mixer
control
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 channel input PGA stage to left
output mixer
0 = not selected
1 = selected
4:2
BYPLMIXVOL
5
AUXL2LMIX
8:6
AUXLMIXVOL
R50 (32h)
Left channel
output mixer
control
w
BIT
000
Volume control for Left channel
input PGA to left output channel
mixer
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
0
Left Auxiliary input to left channel
output mixer:
0 = not selected
1 = selected
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
PP, Rev 3.1, February 2007
39
WM8986
Pre-Production
REGISTER
ADDRESS
R51 (33h)
Right channel
output mixer
control
R3 (03h)
Power
management
3
BIT
LABEL
DEFAULT
DESCRIPTION
0
DACR2RMIX
1
Right DAC output to right output
mixer
0 = not selected
1 = selected
1
BYPR2RMIX
0
Right channel input PGA stage to
right output mixer
0 = not selected
1 = selected
4:2
BYPRMIXVOL
000
Volume control for Right channel
input PGA stage to right output
mixer
000 = -15dB
001 = -12dB
010 = -9dB
011 = -6dB
100 = -3dB
101 = 0dB
110 = +3dB
111 = +6dB
5
AUXR2RMIX
8:6
AUXRMIXVOL
2
LMIXEN
0
Left output channel mixer enable:
0 = disabled
1= enabled
3
RMIXEN
0
Right output channel mixer enable:
0 = disabled
1 = enabled
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
Table 22 Left and Right Output Mixer Control
HEADPHONE OUTPUTS (LOUT1 AND ROUT1)
The headphone outputs LOUT1 and ROUT1 can drive a 16Ω or 32Ω headphone load, either through
DC blocking capacitors, or DC-coupled to a buffered midrail reference (LOUT2 or ROUT2), saving a
capacitor (capless mode). When using capless mode AVDD1 and AVDD2 should use the same
supply to maximise supply rejection. OUT3 and OUT4 should not be used as a buffered midrail
reference in capless mode.
w
PP, Rev 3.1, February 2007
40
WM8986
Pre-Production
Headphone Output using DC Blocking Capacitors
DC Coupled Headphone Output
Figure 22 Recommended Headphone Output Configurations
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 16Ω
load and C1, C2 = 220µF:
fc = 1 / 2π RLC1 = 1 / (2π x 16Ω x 220µF) = 45 Hz
In the DC coupled configuration, the headphone pseudo-ground is connected to the buffered midrail
reference pin (LOUT2 or ROUT2). The L/ROUT2 pins can be configured as a DC output driver by
setting the LOUT2MUTE and ROUT2MUTE register bits. 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.
It is not recommended to use DC-coupling to line inputs of another device. Although the built-in short
circuit protection on the headphone outputs would be tolerant of shorts to ground, such a connection
could be noisy, and may not function properly if the other device is grounded. DC-coupled
configurations should only be used with headphones.
w
PP, Rev 3.1, February 2007
41
WM8986
Pre-Production
REGISTER
ADDRESS
R52 (34h)
LOUT1
Volume
control
R53
ROUT1
Volume
control
BIT
LABEL
DEFAULT
111001
(0dB)
DESCRIPTION
5:0
LOUT1VOL
6
LOUT1MUTE
0
Left headphone output mute:
0 = Normal operation
1 = Mute
7
LOUT1ZC
0
Headphone volume zero cross
enable:
1 = Change gain on zero cross only
0 = Change gain immediately
8
HPVU
Not latched
LOUT1 and ROUT1 volumes do not
update until a 1 is written to HPVU
(in reg 52 or 53)
5:0
ROUT1VOL
6
ROUT1MUTE
0
Right headphone output mute:
0 = Normal operation
1 = Mute
7
ROUT1ZC
0
Headphone volume zero cross
enable:
1 = Change gain on zero cross only
0 = Change gain immediately
8
HPVU
Not latched
LOUT1 and ROUT1 volumes do not
update until a 1 is written to HPVU
(in reg 52 or 53)
111001
(0dB)
Left headphone output volume:
(1dB steps)
000000 = -57dB
...
111001 = 0dB
...
111111 = +6dB
Right headphone output volume:
(1dB steps)
000000 = -57dB
...
111001 = 0dB
...
111111 = +6dB
Table 23 OUT1 Volume Control
w
PP, Rev 3.1, February 2007
42
WM8986
Pre-Production
CLASS D / CLASS AB HEADPHONE OUTPUTS (LOUT2 AND ROUT2)
The outputs LOUT2 and ROUT2 are designed to drive two headphone loads of 16Ω or 32Ω or line
outputs (See Headphone Output and Line Output sections, respectively). Each output has an
individual volume control PGA, a mute and an enable control bit as shown in Figure 23. LOUT2 and
ROUT2 output the left and right channel mixer outputs respectively.
REGISTER
ADDRESS
BIT
LABEL
R7 (07h)
7:4
DCLKDIV
R23 (17h)
8
CLASSDEN
DEFAULT
DESCRIPTION
1000
Controls clock division from
SYSCLK to generate suitable class
D clock.
Recommended class D clock
frequency = 1.4MHz.
0000 = divide by 1
0010 = divide by 2
0011 = divide by 3
0100 = divide by 4
0101 = divide by 5.5
0110 = divide by 6
1000 = divide by 8
1001 = divide by 12
1010 = divide by 16
0
Enable signal for class D mode on
LOUT2 and ROUT2
0 = Class AB mode
1 = Class D mode
Table 24 Class D Control Registers
When driving headphones using class D outputs it is necessary to use appropriate filtering, placed
close to the device, to minimise EMI emissions from the headphone cable (Refer to "Applications
Information" for more information). This filtering does not prevent class AB mode operation.
Figure 23 LOUT2 and ROUT2 Class D Headphone Configuration
w
PP, Rev 3.1, February 2007
43
WM8986
Pre-Production
Figure 24 LOUT2 and ROUT2 Class AB Headphone Configuration
The output configurations shown in Figure 23 and Figure 24 are both suitable for class AB operation.
The signal output on LOUT2/ROUT2 comes from the Left/Right Mixer circuits and can be any
combination of the DAC output, the output of the input PGA stage, and the AUXL/R inputs. The
LOUT2/ROUT2 volume is controlled by the LOUT2VOL/ ROUT2VOL register bits. Gains over 0dB
may cause clipping if the input signal is too high. The LOUT2MUTE/ ROUT2MUTE register bits
cause these outputs to be muted (the output DC level is driven out). The output pins remain at the
same DC level, so that no click noise is produced when muting or un-muting.
w
PP, Rev 3.1, February 2007
44
WM8986
Pre-Production
REGISTER
ADDRESS
R54 (36h)
LOUT2
Volume
control
R55 (37h)
ROUT2
Volume
control
BIT
LABEL
DEFAULT
111001
DESCRIPTION
5:0
LOUT2VOL
Left output volume:
(1dB steps)
000000 = -57dB
...
111001 = 0dB
...
111111 = +6dB
6
LOUT2MUTE
0
Left output mute:
0 = Normal operation
1 = Mute
7
LOUT2ZC
0
LOUT2 volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
8
OUT2VU
Not latched
LOUT2 and ROUT2 volumes do not
update until a 1 is written to
OUT2VU (in reg 54 or 55)
5:0
ROUT2VOL
6
111001
Right output volume:
(1dB steps)
000000 = -57dB
...
111001 = 0dB
...
111111 = +6dB
ROUT2MUTE
0
Right output mute:
0 = Normal operation
1 = Mute
7
ROUT2ZC
0
ROUT2 volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
8
OUT2VU
Not latched
LOUT2 and ROUT2 volumes do not
update until a 1 is written to
OUT2VU (in reg 54 or 55)
Table 25 OUT2 Volume 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 (07h)
Additional
Control
BIT
0
LABEL
SLOWCLKEN
DEFAULT
0
DESCRIPTION
Slow clock enable.
0 = slow clock disabled
1 = slow clock enabled
Table 26 Timeout Clock Enable Control
Note: SLOWCLKEN is also used for the jack insert detect debounce circuit
w
PP, Rev 3.1, February 2007
45
WM8986
Pre-Production
OUT3/OUT4 MIXERS AND OUTPUT STAGES
The OUT3/OUT4 pins provide an additional stereo line output, a mono output, or a differential output.
There is a dedicated analogue mixer for OUT3 and one for OUT4 as shown in Figure 25.
The OUT3 and OUT4 output stages are powered from AVDD1 and AGND1.
Figure 25 OUT3 and OUT4 Mixers
OUT3 can provide a left line output, or a mono mix line output.
OUT4 can provide 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.
w
PP, Rev 3.1, February 2007
46
WM8986
Pre-Production
REGISTER
ADDRESS
R56 (38h)
OUT3 mixer
control
R57 (39h)
OUT4 mixer
control
BIT
LABEL
DEFAULT
DESCRIPTION
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 PGA output to OUT3
0 = disabled
1 = enabled
1
LMIX2OUT3
0
Left DAC 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 DAC mixer to OUT4
0 = disabled
1 = enabled
3
LDAC2OUT4
0
Left DAC to OUT4
0 = disabled
1 = enabled
2
BYPR2OUT4
0
Right PGA output to OUT4
0 = disabled
1 = enabled
1
RMIX2OUT4
0
Right DAC mixer to OUT4
0 = disabled
1 = enabled
0
RDAC2OUT4
1
Right DAC output to OUT4
0 = disabled
1 = enabled
Table 27 OUT3/OUT4 Mixer Registers
w
PP, Rev 3.1, February 2007
47
WM8986
Pre-Production
ENABLING THE OUTPUTS
Each analogue output of the WM8986 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 WM8986 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 (01h)
Power
Management
1
R2 (02h)
Power
Management
2
R3 (03h)
Power
Management
3
BIT
LABEL
DEFAULT
DESCRIPTION
2
BUFIOEN
0
Unused input/output bias buffer enable
6
OUT3MIXEN
0
OUT3 mixer enable
7
OUT4MIXEN
0
OUT4 mixer enable
8
ROUT1EN
0
ROUT1 output enable
7
LOUT1EN
0
LOUT1 output enable
6
SLEEP
0
0 = Normal device operation
1 = Supply current reduced in device
standby mode when clock supplied
2
LMIXEN
0
Left mixer enable
3
RMIXEN
0
Right mixer enable
5
LOUT2EN
0
LOUT2 output enable
6
ROUT2EN
0
ROUT2 output enable
7
OUT3EN
0
OUT3 enable
8
OUT4EN
0
OUT4 enable
Note: All “Enable” bits are 1 = ON, 0 = OFF
Table 28 Output Stages Power Management Control
THERMAL SHUTDOWN
To protect the WM8986 from becoming too hot, a thermal sensor has been built in. If the device
junction temperature reaches approximately 125°C and the TSDEN and TSOPCTRL bit are set, then
all outputs will be disabled to avoid further increase of the chip temperature.
Additionally, when the device is too hot and TSDEN is set, then the WM8986 de-asserts GPIO bit 11,
a virtual GPIO that can be set up to generate an interrupt to the CPU (see “GPIO and Interrupt
Control” section).
REGISTER
ADDRESS
R49 (31h)
Output Control
BIT
LABEL
DEFAULT
DESCRIPTION
1
TSDEN
0
Thermal Sensor Enable
0 = disabled
1 = enabled
2
TSOPCTRL
0
Thermal Shutdown Output enable
0 = Disabled
1 = Enabled, i.e. all outputs will be
disabled if TI set and the device junction
temperature is more than 125ºC.
Table 29 Thermal Shutdown
UNUSED ANALOGUE INPUTS/OUTPUTS
Whenever an analogue input/output is disabled, it remains connected to a voltage source (AVDD1/2)
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 30kΩ.
w
PP, Rev 3.1, February 2007
48
WM8986
Pre-Production
REGISTER
ADDRESS
R49 (31h)
BIT
0
LABEL
VROI
DEFAULT
0
DESCRIPTION
VREF (AVDD1/2) to analogue output
resistance
0 = approx 1kΩ
1 = approx 30 kΩ
Table 30 Disabled Outputs to VREF Resistance
A dedicated buffer is available for biasing unused analogue I/O pins as shown in Figure 26. This
buffer can be enabled using the BUFIOEN register bit.
Figure 26 summarises the bias options for the output pins.
Figure 26 Unused Input/Output Pin Tie-off Buffers
L/ROUT2EN/
OUT3/4EN
VROI
OUTPUT CONFIGURATION
0
0
1kΩ to AVDD1/2
0
1
30kΩ to AVDD1/2
1
X
Output enabled (DC level=AVDD1/2)
Table 31 Unused Output Pin Bias Options
w
PP, Rev 3.1, February 2007
49
WM8986
Pre-Production
DIGITAL AUDIO INTERFACES
The audio interface has three pins:
•
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 WM8986 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
I 2S
DSP mode A
•
DSP mode B
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 WM8986 audio interface may be configured as either master or slave. As a master interface
device the WM8986 generates BCLK and LRC and thus controls sequencing of the data transfer on
DACDAT. To set the device to master mode register bit MS should be set high. In slave mode
(MS=0), the WM8986 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.
Figure 27 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.
Figure 28 Right Justified Audio Interface (assuming n-bit word length)
w
PP, Rev 3.1, February 2007
50
WM8986
Pre-Production
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.
Figure 29 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 30 and Figure
31. In device slave mode, Figure 32 and Figure 33, 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.
Figure 30 DSP/PCM Mode Audio Interface (mode A, LRP=0, Master)
Figure 31 DSP/PCM Mode Audio Interface (mode B, LRP=1, Master)
w
PP, Rev 3.1, February 2007
51
WM8986
Pre-Production
Figure 32 DSP/PCM Mode Audio Interface (mode A, LRP=0, Slave)
Figure 33 DSP/PCM Mode Audio Interface (mode B, LRP=0, Slave)
w
PP, Rev 3.1, February 2007
52
WM8986
Pre-Production
REGISTER
ADDRESS
R4 (04h)
Audio
Interface
Control
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 only.
2
DLRSWAP
0
Controls whether DAC data appears in
‘right’ or ‘left’ phases of LRC clock:
0 = DAC left data appear in ‘left’ phase
of LRC and right data in 'right' phase
1 = DAC left data appear 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
DSP Mode – mode A/B select
0 = MSB is available on 2nd BCLK rising
edge after LRC rising edge (mode A)
1 = MSB is available on 1st BCLK rising
edge after LRC rising edge (mode B)
8
BCP
0
BCLK polarity
0 = normal
1 = inverted
Table 32 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.
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 frequency of BCLK in master mode can be controlled with BCLKDIV. The
frequencies of BCLK and LRC are also controlled by MCLKDIV. The LRC sample rate is set to the
required values by MCLKDIV and the BCLK rate will be set accordingly to provide sufficient BCLKs
for that chosen sample rate. These clocks are divided down versions of master clock.
w
PP, Rev 3.1, February 2007
53
WM8986
Pre-Production
REGISTER
ADDRESS
R6 (06h)
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
1 = BCLK and LRC clock are outputs
generated by the WM8986 (MASTER)
4:2
BCLKDIV
000
Configures the BCLK output frequency,
for use when the chip is master over
BCLK.
000 = divide by 1 (BCLK=SYSCLK)
001 = divide by 2 (BCLK=SYSCLK/2)
010 = divide by 4 (BCLK=SYSCLK/4)
011 = divide by 8 (BCLK=SYSCLK/8)
100 = divide by 16 (BCLK=SYSCLK/16)
101 = divide by 32 (BCLK=SYSCLK/32)
110 = reserved
111 = reserved
7:5
MCLKDIV
010
Sets the scaling for SYSCLK clock
output (under control of CLKSEL)
000 = divide by 1 (LRC=SYSCLK/128)
001 = divide by 1.5 (LRC=SYSCLK/192)
010 = divide by 2 (LRC=SYSCLK/256)
011 = divide by 3 (LRC=SYSCLK/384)
100 = divide by 4 (LRC=SYSCLK/512)
101 = divide by 6 (LRC=SYSCLK/768)
110 = divide by 8 (LRC=SYSCLK/1024)
111 = divide by 12 (LRC=SYSCLK/1536)
8
CLKSEL
1
Controls the source of the clock for all
internal operation:
0 = MCLK
1 = PLL output
Table 33 Clock Control
AUDIO SAMPLE RATES
The WM8986 DAC limiter characteristics are sample rate dependent. SR should be set to the
correct sample rate or the closest value if the actual sample rate is not available.
If a sample rate that is not explicitly supported by the SR register settings is required then the closest
SR value to that sample rate should be chosen. The DAC limiter characteristics will scale
appropriately.
REGISTER
ADDRESS
R7 (07h)
Additional
Control
BIT
3:1
LABEL
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 45 Sample Rate Control
w
PP, Rev 3.1, February 2007
54
WM8986
Pre-Production
MASTER CLOCK AND PHASE LOCKED LOOP (PLL)
The WM8986 has an on-chip phase-locked loop (PLL) circuit that can be used to:
Generate master clocks for the WM8986 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 shows the PLL and internal clocking on the WM8986.
The PLL can be enabled or disabled by the PLLEN register bit.
REGISTER
ADDRESS
R1 (01h)
Power
management 1
BIT
5
LABEL
PLLEN
DEFAULT
0
DESCRIPTION
PLL enable
0 = PLL off
1 = PLL on
Table 46 PLLEN Control Bit
Figure 38 PLL and Clock Select Circuit
The PLL frequency ratio R = f2/f1 (see Figure ) can be set using the register bits PLLK and PLLN:
PLLN = int R
PLLK = int (224 (R-PLLN))
EXAMPLE:
MCLK=12MHz, required clock = 12.288MHz.
R should be chosen to ensure 5 < PLLN < 13. There is a fixed divide by 4 in the PLL and a
selectable divide by N after the PLL which should be set to divide by 2 to meet this requirement.
Enabling the divide by 2 sets the required f2 = 4 x 2 x 12.288MHz = 98.304MHz.
R = 98.304 / 12 = 8.192
PLLN = int R = 8
k = int ( 224 x (8.192 – 8)) = 3221225 = 3126E9h
w
PP, Rev 3.1, February 2007
55
WM8986
Pre-Production
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R36 (24h)
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 (25h)
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 (26h)
PLL K Value
2
8:0
PLLK [17:9]
093h
R39 (27h)
PLL K Value
3
8:0
PLLK [8:0]
0E9h
Table 47 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 48.
f2
(MHz)
12
11.29
90.3168
1
2
7.5264
7h
86C226h
12
12.288
98.304
1
2
8.192
8h
3126E8h
13
11.29
90.3168
1
2
6.947446
6h
13
12.288
98.304
1
2
7.561846
7h
14.4
11.29
90.3168
1
2
6.272
14.4
12.288
98.304
1
2
19.2
11.29
90.3168
2
2
R
N
K
MCLKDIV
PLLPRESCALE
DESIRED
OUTPUT
(SYSCLK)
(MHz)
MCLK
(MHz)
(f1)
N
REGISTER
R36[3:0]
K REGISTERS
R37
R38
R39
XX7h
021h
161h
026h
XX8h
00Ch
093h
0E8h
F28BD4h
XX6h
03Ch
145h
1D4h
8FD525h
XX7h
023h
1EAh
125h
6h
45A1CAh
XX6h
011h
0D0h
1CAh
6.826667
6h
D3A06Eh
XX6h
034h
1D0h
06Eh
9.408
9h
6872AFh
XX9h
01Ah
039h
0AFh
19.2
12.288
98.304
2
2
10.24
Ah
3D70A3h
XXAh
00Fh
0B8h
0A3h
19.68
11.29
90.3168
2
2
9.178537
9h
2DB492h
XX9h
00Bh
0DAh
092h
19.68
12.288
98.304
2
2
9.990243
9h
FD809Fh
XX9h
03Fh
0C0h
09Fh
19.8
11.29
90.3168
2
2
9.122909
9h
1F76F7h
XX9h
007h
1BBh
0F7h
19.8
12.288
98.304
2
2
9.929697
9h
EE009Eh
XX9h
03Bh
100h
09Eh
24
11.29
90.3168
2
2
7.5264
7h
86C226h
XX7h
021h
161h
026h
24
12.288
98.304
2
2
8.192
8h
3126E8h
XX8h
00Ch
093h
0E8h
26
11.29
90.3168
2
2
6.947446
6h
F28BD4h
XX6h
03Ch
145h
1D4h
26
12.288
98.304
2
2
7.561846
7h
8FD525h
XX7h
023h
1EAh
125h
27
11.29
90.3168
2
2
6.690133
6h
B0AC93h
XX6h
02Ch
056h
093h
27
12.288
98.304
2
2
7.281778
7h
482296h
XX7h
012h
011h
096h
Table 48 PLL Frequency Examples
w
PP, Rev 3.1, February 2007
56
WM8986
Pre-Production
COMPANDING
The WM8986 supports A-law and µ-law companding. Companding can be enabled on the DAC
audio interface by writing the appropriate value to the DAC_COMP register bit.
REGISTER
ADDRESS
R5 (05h)
Companding
Control
BIT
LABEL
DEFAULT
DESCRIPTION
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 49 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:
µ-law (where µ=255 for the U.S. and Japan):
F(x) = ln( 1 + µ|x|) / ln( 1 + µ)
-1 ≤ x ≤ 1
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 µ-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 (µ-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 8bit 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 50 8-bit Companded Word Composition
w
PP, Rev 3.1, February 2007
57
WM8986
Pre-Production
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 39 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 40 A-Law Companding
w
PP, Rev 3.1, February 2007
58
WM8986
Pre-Production
GENERAL PURPOSE INPUT/OUTPUT
The WM8986 has one dual purpose input/output pin, CSB/GPIO1.
The GPIO1 function is provided for use as jack detection input or general purpose output.
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 34 illustrates the functionality of the GPIO1 pin when used as a general purpose output.
REGISTER
ADDRESS
R8 (08h)
GPIO
Control
BIT
LABEL
DEFAULT
DESCRIPTION
2:0
GPIO1SEL
000
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
6
GPIO1GPD
0
GPIO1 Internal pull-down enable:
0 = Internal pull-down disabled
1 = Internal pull-down enabled
7
GPIO1GPU
0
GPIO1 Internal pull-up enable:
0 = Internal pull-up disabled
1 = Internal pull-up enabled
8
GPIO1GP
0
GPIO1 Open drain enable
0 = Open drain disabled
1 = Open drain enabled
Table 34 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.
w
PP, Rev 3.1, February 2007
59
WM8986
Pre-Production
For further details of the jack detect operation see the OUTPUT SWITCHING section.
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 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:
The SLOWCLKEN bit must be enabled for the jack detect circuitry to operate.
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 debounce). 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 28).
When an output is normally enabled at per Table 28, 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 28.
w
PP, Rev 3.1, February 2007
60
WM8986
Pre-Production
BIT
LABEL
DEFAULT
DESCRIPTION
REGISTER
ADDRESS
R9 (09h)
GPIO control
6
JD_EN
0
Jack Detection Enable
0 = disabled
1 = enabled
R13 (00h)
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 35 Jack Detect Register Control Bits
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 36.
The WM8986 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 36 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.
Figure 34 3-Wire Serial Control Interface
w
PP, Rev 3.1, February 2007
61
WM8986
Pre-Production
2-WIRE SERIAL CONTROL MODE
The WM8986 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 WM8986).
The WM8986 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 WM8986, the WM8986 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 WM8986
returns to the idle condition and waits for a new start condition and valid address.
During a write, once the WM8986 has acknowledged a correct address, the controller sends the first
byte of control data (B15 to B8, i.e. the WM8986 register address plus the first bit of register data).
The WM8986 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 WM8986 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 WM8986 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.
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 35 2-Wire Serial Control Interface
In 2-wire mode the WM8986 has a fixed device address, 0011010.
RESETTING THE CHIP
The WM8986 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 WM8986 requires four separate power supplies:
AVDD1 and AGND1: Analogue supply, powers all internal analogue functions and output drivers
LOUT1, ROUT1, OUT3 and OUT4. 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 and ROUT2. AVDD2 must be between
2.5V and 3.6V. 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 interface pads.
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.
w
PP, Rev 3.1, February 2007
62
WM8986
Pre-Production
POWER MANAGEMENT
SAVING POWER BY REDUCING OVERSAMPLING RATE
The default mode of operation of the DAC digital filters is in 64x oversampling mode. Under the
control of 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
R10 (0Ah)
DAC control
BIT
LABEL
3
DEFAULT
DACOSR128
0
DESCRIPTION
DAC oversample rate select
0 = 64x (lowest power)
1 = 128x (best SNR)
Table 37 DAC Oversampling Rate Selection
LOW POWER MODE
If only limited functionality is required, the WM8986 can be put into a low power mode. In this mode,
the DSP core runs at half of the normal rate, reducing digital power consumption of the core by half.
For DAC low power only, 3D enhancement with 2-Band equaliser functionality is permitted, where
only Band 1 (low shelf) and Band 5 (high shelf) can be used. .
REGISTER
ADDRESS
R7 (07h)
Additional Ctrl
BIT
LABEL
8
DEFAULT
M128ENB
0
DESCRIPTION
0 = low power mode enabled
1 = low power mode disabled
Table 38 DSP Core Low Power Mode Control
The register settings for this low-power mode are detailed below. The device will not enter low power
unless in this register configuration, regardless of M128ENB.
For pop-free operation of the device it is recommended to change the M128ENB low power
functionality only when both DACs are disabled, i.e. when DACENL=0 and DACENR=0.
FUNCTION
DAC low power
REGISTER BITS
SETTING
M128ENB
DACENL
DACENR
0
1
1
DESCRIPTION
Either or both of DACENL and
DACENR must be set (mono or
stereo mode)
Table 39 DSP Core Low Power Mode Register Settings
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 (01h)
Power
management 1
BIT
1:0
LABEL
DEFAULT
VMIDSEL
00
DESCRIPTION
Reference string impedance to VMID pin
00= off (250kΩ VMID to AGND1)
01=75kΩ
10=300kΩ
11=5kΩ
Table 40 VMID Impedance Control
BIASEN
The analogue amplifiers will not operate unless BIASEN is enabled.
REGISTER
ADDRESS
R1 (01h)
Power
management 1
BIT
3
LABEL
BIASEN
DEFAULT
0
DESCRIPTION
Analogue amplifier bias control
0 = disabled
1 = enabled
Table 41 Analogue Bias Control
w
PP, Rev 3.1, February 2007
63
WM8986
Pre-Production
REGISTER MAP
ADDR
B[15:9]
REGISTER
NAME
B8
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
VAL
(HEX)
DEC HEX
0
00
Software Reset
1
01
Power manage’t 1
0
OUT4MIX
EN
OUT3MIX
EN
PLLEN
0
BIASEN
BUFIOEN
VMIDSEL [1:0]
000
2
02
Power manage’t 2
ROUT1EN
LOUT1EN
SLEEP
BOOST
ENR
BOOST
ENL
INPGA
ENR
INPPGA
ENL
0
0
000
3
03
Power manage’t 3
OUT4EN
OUT3EN
ROUT2EN LOUT2EN
0
RMIXEN
4
04
Audio Interface
BCP
LRP
WL[1:0]
5
05
Companding ctrl
0
0
6
06
Clock Gen ctrl
CLKSEL
7
07
Additional ctrl
M128ENB
8
08
GPIO Stuff
GPIO1GP
9
09
Jack detect control
0
0
JD_EN
0
0
0
0
10
0A
DAC Control
0
0
SOFT
MUTE
0
0
DACOSR
128
AMUTE
11
0B
Left DAC digital Vol
DACVU
DACLVOL[7:0]
12
0C
Right DAC dig’l Vol
DACVU
DACRVOL[7:0]
13
0D
Jack Detect Control
0
14
0E
Reserved
000000000
000
15
0F
Reserved
000000000
000
16
10
Reserved
000000000
18
12
EQ1 – low shelf
EQ3DEN
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]
23
17
Class D Control
CLASSDEN
0
24
18
DAC Limiter 1
LIMEN
25
19
DAC Limiter 2
0
27
1B
Reserved
000000000
000
28
1C
Reserved
000000000
000
29
1D
Reserved
000000000
000
30
1E
Reserved
000000000
000
32
20
Reserved
000000000
000
33
21
Reserved
000000000
000
34
22
Reserved
000000000
000
35
23
Reserved
000000000
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
0
0
0
0
0
42
2A
Biasing
0
0
0
0
0
0
POBCTRL
0
0
000
43
2B
Beep control
BYPL2
RMIX
BYPR2
LMIX
0
0
0
0
0
0
0
000
44
2C
Input ctrl
0
0
0
RIN2
INPPGA
RIP2
INPPGA
0
0
LIN2
INPPGA
LIP2
INPPGA
003
w
Software reset
0
WL8
LMIXEN
DACENR
DACENL
000
FMT[1:0]
DLRSWAP
0
MONO
050
DAC_COMP [1:0]
0
0
0
000
0
MS
140
SLOWCLK
EN
080
MCLKDIV[2:0]
BCLKDIV[2:0]
DCLKDIV[3:0]
GPIO1GPU GPIO1GPD
SR[2:0]
OPCLKDIV[2:0]
GPIO1POL
0
DACRPOL DACLPOL
000
000
0FF
000
000
0
02C
10
LIMLVL[2:0]
0
0
JD_EN0[3:0]
0
0
008
LIMATK[3:0]
032
LIMBOOST[3:0]
000
LIMDCY[3:0]
0
0
0FF
JD_EN1[3:0]
0
000
GPIO1SEL[2:0]
000
PLLPRE
SCALE
008
PLLN[3:0]
00C
PLLK[23:18]
000
DEPTH3D[3:0]
PP, Rev 3.1, February 2007
64
WM8986
Pre-Production
ADDR
B[15:9]
REGISTER
NAME
B8
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
VAL
(HEX)
DEC HEX
45
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 Input BOOST
control
PGA
BOOSTL
0
0
0
0
0
AUXL2BOOSTVOL[2:0]
100
48
30
PGA
Right Input BOOST
control
BOOSTR
0
0
0
0
0
AUXR2BOOSTVOL[2:0]
100
49
31
Output ctrl
0
DACL2
RMIX
DACR2
LMIX
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
LOUT1ZC
LOUT1
MUTE
LOUT1VOL[5:0]
039
53
35
ROUT1 (HP)
volume ctrl
OUT1VU
ROUT1ZC
ROUT1
MUTE
ROUT1VOL[5:0]
039
54
36
LOUT2 (SPK)
volume ctrl
OUT2VU
LOUT2ZC
LOUT2
MUTE
LOUT2VOL[5:0]
039
55
37
ROUT2 (SPK)
volume ctrl
OUT2VU
ROUT2ZC
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
OUT
3_2OUT4
OUT4
MUTE
OUT4
ATTN
LMIX2
OUT4
LDAC2
OUT4
BYPR2
OUT4
RMIX2
OUT4
RDAC2
OUT4
001
61
3D
Bias Control
BIASCUT
0
0
0
0
TSDEN
VROI
002
BYPLMIXVOL[2:0]
BYPL2
LMIX
DACL2
LMIX
001
BYPRMIXVOL[2:0]
BYPR2
RMIX
DACR2
RMIX
001
00
TSOP
CTRL
00
0
000
Table 42 WM8986 Register Map
w
PP, Rev 3.1, February 2007
65
WM8986
Pre-Production
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 as "Reserved" should not be changed from the default.
REGISTER
ADDRESS
BIT
0 (00h)
[8:0]
1 (01h)
8
LABEL
RESET
DESCRIPTION
REFER TO
N/A
Software reset
Resetting the
Chip
0
Reserved
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)
0
Reserved
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
00= off (250kΩ VMID to AGND1)
01=75kΩ
10=300kΩ
11=5kΩ
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
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
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
4
2 (02h)
DEFAULT
1
0
Reserved
0
0
Reserved
w
PP, Rev 3.1, February 2007
66
WM8986
Pre-Production
REGISTER
ADDRESS
3 (03h)
BIT
LABEL
REFER TO
OUT4EN
0
OUT4 enable
0 = disabled
1 = enabled
Power
Management
7
OUT3EN
0
OUT3 enable
0 = disabled
1 = enabled
Power
Management
6
ROUT2EN
0
ROUT2 enable
0 = disabled
1 = enabled
Power
Management
5
LOUT2EN
0
LOUT2 enable
0 = disabled
1 = enabled
Power
Management
0
Reserved
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
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 appear in ‘left’ phase of LRC
1=DAC data appears in ‘right’ phase of LRC
Digital Audio
Interfaces
0
Reserved
MONO
0
Selects between stereo and mono device
operation:
0=Stereo device operation
1=Mono device operation. Data appears in ‘left’
phase of LRC
000
Reserved
1
0
5 (05h)
DESCRIPTION
8
4
4 (04h)
DEFAULT
8:6
w
Digital Audio
Interfaces
PP, Rev 3.1, February 2007
67
WM8986
REGISTER
ADDRESS
Pre-Production
BIT
LABEL
REFER TO
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 (linear mode)
01=reserved
10=µ-law
11=A-law
Digital Audio
Interfaces
000
Reserved
8
CLKSEL
1
Controls the source of the clock for all internal
operation:
0=MCLK
1=PLL output
Digital Audio
Interfaces
7:5
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
4:2
BCLKDIV
000
Configures the BCLK output frequency, for use
when the chip is master over BCLK.
000=divide by 1 (BCLK=MCLK)
001=divide by 2 (BCLK=MCLK/2)
010=divide by 4
011=divide by 8
100=divide by 16
101=divide by 32
110=reserved
111=reserved
Digital Audio
Interfaces
1
7 (07h)
DESCRIPTION
5
2:0
6 (06h)
DEFAULT
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 WM8978 (MASTER)
Digital Audio
Interfaces
8
M128ENB
0
0 = low power mode enabled
1 = low power mode disabled
Additional
Control
7:4
DCLKDIV
1000
Controls clock division from SYSCLK to
generate suitable class D clock.
Recommended class D clock frequency =
1.4MHz.
0000 = divide by 1
0010 = divide by 2
0011 = divide by 3
0100 = divide by 4
0101 = divide by 5.5
0110 = divide by 6
1000 = divide by 8
1001 = divide by 12
1010 = divide by 16
Class A / D
Headphone
Outputs
w
PP, Rev 3.1, February 2007
68
WM8986
Pre-Production
REGISTER
ADDRESS
8 (08h)
9 (09h)
BIT
LABEL
DESCRIPTION
REFER TO
3:1
SR
000
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
Audio Sample
Rates
0
SLOWCLKEN
0
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
Analogue
Outputs
8
GPIO1GP
0
GPIO1 Open drain enable
0 = Open drain disabled
1 = Open drain enabled
General
Purpose
Input/Output
(GPIO)
7
GPIO1GPU
0
GPIO1 Internal pull-up enable:
0 = Internal pull-up disabled
1 = Internal pull-up enabled
General
Purpose
Input/Output
(GPIO)
6
GPIO1GPD
0
GPIO1 Internal pull-down enable:
0 = Internal pull-down disabled
1 = Internal pull-down enabled
General
Purpose
Input/Output
(GPIO)
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)
001= reserved
010=Temp ok
011=Amute active
100=PLL clk o/p
101=PLL lock
110=logic 1
111=logic 0
General
Purpose
Input/Output
(GPIO)
00
Reserved
0
Jack Detection Enable
0=disabled
1=enabled
Output
Switching
(Jack Detect)
000000
Reserved
Output
Switching
(Jack Detect)
00
Reserved
0
Softmute enable:
0=Disabled
1=Enabled
8:7
6
JD_EN
5:0
10 (0Ah)
DEFAULT
8:7
6
SOFTMUTE
w
Output Signal
Path
PP, Rev 3.1, February 2007
69
WM8986
REGISTER
ADDRESS
Pre-Production
BIT
LABEL
5:4
11 (0Bh)
12 (0Ch)
13 (0Dh)
DEFAULT
DESCRIPTION
REFER TO
00
Reserved
3
DACOSR128
0
DAC oversample rate select
0 = 64x (lowest power)
1 = 128x (best SNR)
Power
Management
2
AMUTE
0
Automute enable
0 = Amute disabled
1 = Amute enabled
Output Signal
Path
1
DACPOLR
0
Right DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
Output Signal
Path
0
DACPOLL
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
DACVOLL
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
DACVOLR
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
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.
[0]= OUT1_EN_0
[1]= OUT2_EN_0
[2]= OUT3_EN_0
[3]= OUT4_EN_0
Output
Switching
(Jack Detect)
Reserved
8
14 (0Eh)
8:0
000000000
15 (0Fh)
8:0
000000000
Reserved
16 (10h)
8:0
000000000
Reserved
18 (12h)
8:7
6:5
EQ1C
00
Reserved
EQ3DEN
01
EQ Band 1 Cut-off Frequency:
Output Signal
Path
00=80Hz
01=105Hz
10=135Hz
11=175Hz
4:0
EQ1G
w
01100
EQ Band 1 Gain Control. See Table 20 for
details.
Output Signal
Path
PP, Rev 3.1, February 2007
70
WM8986
Pre-Production
REGISTER
ADDRESS
19 (13h)
BIT
8
LABEL
EQ2BW
7
6:5
EQ2C
DEFAULT
DESCRIPTION
REFER TO
0
EQ Band 2 Bandwidth Control
0=narrow bandwidth
1=wide bandwidth
Output Signal
Path
0
Reserved
Output Signal
Path
01
EQ Band 2 Centre Frequency:
Output Signal
Path
00=230Hz
01=300Hz
10=385Hz
11=500Hz
20 (14h)
4:0
EQ2G
01100
EQ Band 2 Gain Control. See Table 20 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
01
EQ Band 3 Centre Frequency:
Output Signal
Path
7
6:5
EQ3C
00=650Hz
01=850Hz
10=1.1kHz
11=1.4kHz
21 (15h)
4:0
EQ3G
01100
EQ Band 3 Gain Control. See Table 20 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
01
EQ Band 4 Centre Frequency:
Output Signal
Path
7
6:5
EQ4C
00=1.8kHz
01=2.4kHz
10=3.2kHz
11=4.1kHz
4:0
22 (16h)
EQ4G
8:7
6:5
EQ5C
01100
EQ Band 4 Gain Control. See Table 20 for
details.
Output Signal
Path
0
Reserved
Output Signal
Path
01
EQ Band 5 Cut-off Frequency:
Output Signal
Path
00=5.3kHz
01=6.9kHz
10=9kHz
11=11.7kHz
4:0
EQ5G
01100
EQ Band 5 Gain Control. See Table 20 for
details.
Output Signal
Path
23 (17h)
8
CLASSDEN
0
Enable signal for class D mode on LOUT2 and
ROUT2
0 = Class AB mode
1 = Class D mode
Class D
Control
000 0000
Reserved. Initialise to 0
24 (18h)
8
0
Enable the DAC digital limiter:
0=disabled
1=enabled
7:0
LIMEN
w
Output Signal
Path
PP, Rev 3.1, February 2007
71
WM8986
REGISTER
ADDRESS
Pre-Production
BIT
7:4
LABEL
LIMDCY
DEFAULT
0011
DESCRIPTION
REFER TO
DAC Limiter Decay time (per 6dB gain change)
for 44.1kHz sampling. Note that these will scale
Output Signal
Path
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
3:0
LIMATK
0010
DAC Limiter Attack time (per 6dB gain change)
for 44.1kHz sampling. Note that these will scale
with sample rate.
Output Signal
Path
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
25 (19h)
8:7
6:4
LIMLVL
00
Reserved
000
Programmable signal threshold level
(determines level at which the DAC limiter starts
to operate)
Output Signal
Path
000=-1dB
001=-2dB
010=-3dB
011=-4dB
100=-5dB
101 to 111=-6dB
3:0
LIMBOOST
0000
DAC Limiter volume boost (can be used as a
stand alone volume boost when LIMEN=0):
0000=0dB
Output Signal
Path
0001=+1dB
0010=+2dB
… (1dB steps)
1011=+11dB
1100=+12dB
1101 to 1111=reserved
27 (1Bh)
8:0
000000000
Reserved
28 (1Ch)
8:0
000000000
Reserved
29 (1Dh)
8:0
000000000
Reserved
30 (1Eh)
8:0
000000000
Reserved
32 (20h)
8:0
000000000
Reserved
33 (21h)
8:0
000000000
Reserved
w
8
PP, Rev 3.1, February 2007
72
WM8986
Pre-Production
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
34 (22h)
8:0
000000000
Reserved
35 (23h)
8:0
000000000
Reserved
36 (24h)
8:5
0000
Reserved
37 (25h)
REFER TO
4
PLL
PRESCALE
0
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
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)
00000
Reserved
DEPTH3D
0000
Stereo depth
0000: 0% (minimum 3D effect)
0001: 6.67%
....
1110: 93.3%
1111: 100% (maximum 3D effect)
3D Stereo
Enhancement
0000 00
Reserved
0
VMID independent current bias control
0 = Disable VMID independent current bias
1 = Enable VMID independent current bias
Analogue
Outputs
41 (29h)
8:6
8:4
3:0
42 (2Ah)
8:3
2
POBCTRL
1:0
43 (2Bh)
44 (2Ch)
00
Reserved
8
BYPL2RMIX
0
Left channel input PGA stage to right output
mixer
0 = not selected
1 = selected
Analogue
Outputs
7
BYPR2LMIX
0
Right channel input PGA stage to Left output
mixer
0 = not selected
1 = selected
Analogue
Outputs
8
0
Reserved
7
0
Reserved
6
0
Reserved
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
w
PP, Rev 3.1, February 2007
73
WM8986
REGISTER
ADDRESS
45 (2Dh)
46 (2Eh)
47 (2Fh)
Pre-Production
BIT
LABEL
DEFAULT
DESCRIPTION
3
0
Reserved
2
0
Reserved
REFER TO
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
INPPGAU
N/A
INPPGAVOLL and INPPGAVOLR volume do
not update until a 1 is written to
INPPGAUPDATE (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
5:0
INPPGAVOLL
010000
Left channel input PGA volume
000000 = -12dB
000001 = -11.25db
.
010000 = 0dB
.
111111 = 35.25dB
Input Signal
Path
8
INPPGAU
N/A
INPPGAVOLL and INPPGAVOLR 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
00000
Reserved
7:3
w
PP, Rev 3.1, February 2007
74
WM8986
Pre-Production
REGISTER
ADDRESS
48 (30h)
BIT
LABEL
REFER TO
AUXL2BOOSTVOL
000
Controls the auxilliary amplifer to the left channel
input boost stage:
000=Path disabled (disconnected)
001=-12dB gain through boost stage
010=-9dB gain through boost stage
…
111=+6dB gain through boost stage
Input Signal
Path
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.
Input Signal
Path
00000
Reserved
AUXR2BOOSTVOL
000
Controls the auxilliary amplifer to the right
channel input boost stage:
000=Path disabled (disconnected)
001=-12dB gain through boost stage
010=-9dB gain through boost stage
…
111=+6dB gain through boost stage
7:3
8:7
Input Signal
Path
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
4:3
50 (32h)
DESCRIPTION
2:0
2:0
49 (31h)
DEFAULT
00
Reserved. Initialise to 0
2
TSOPCTRL
0
Thermal Shutdown Output enable
0 = Disabled
1 = Enabled, i.e. all outputs will be disabled if TI
set and the device junction temperature is more
than 125ºC.
Analogue
Outputs
1
TSDEN
1
Thermal Shutdown Enable
0 : thermal shutdown disabled
1 : thermal shutdown enabled
Analogue
Outputs
0
VROI
0
VREF (AVDD/2 or 1.5xAVDD/2) to analogue
output resistance
0: approx 1kΩ
1: approx 30 kΩ
Analogue
Outputs
8:6
AUXLMIXVOL
000
Aux left channel input to left mixer volume
control:
000 = -15dB
001 = -12dB
…
101 = 0dB
110 = +3dB
111 = +6dB
Analogue
Outputs
5
AUXL2LMIX
0
Left Auxilliary input to left channel output mixer:
0 = not selected
1 = selected
Analogue
Outputs
w
PP, Rev 3.1, February 2007
75
WM8986
REGISTER
ADDRESS
51 (33h)
52 (34h)
Pre-Production
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
4:2
BYPLMIXVOL
000
Volume control for left input PGA to left output
mixer:
000 = -15dB
001 = -12dB
…
101 = 0dB
110 = +3dB
111 = +6dB
Analogue
Outputs
1
BYPL2L
MIX
0
Left channel input boost output to left output
mixer
0 = not selected
1 = selected
Analogue
Outputs
0
DACL2L
MIX
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:
000 = -15dB
001 = -12dB
…
101 = 0dB
110 = +3dB
111 = +6dB
Analogue
Outputs
5
AUXR2RMIX
0
Right Auxilliary input to right channel output
mixer:
0 = not selected
1 = selected
Analogue
Outputs
4:2
BYPRMIXVOL
000
Volume control for right channel input PAG to
right output channel mixer:
000 = -15dB
001 = -12dB
…
101 = 0dB
110 = +3dB
111 = +6dB
Analogue
Outputs
1
BYPR2RMIX
0
Right channel input boost output to right output
mixer
0 = not selected
1 = selected
Analogue
Outputs
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
w
PP, Rev 3.1, February 2007
76
WM8986
Pre-Production
REGISTER
ADDRESS
53 (35h)
54 (36h)
55 (37h)
56 (38h)
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
5:0
LOUT1VOL
111001
Left headphone output volume:
000000 = -57dB
...
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
...
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
Speaker volume zero cross enable:
1 = Change gain on zero cross only
0 = Change gain immediately
Analogue
Outputs
6
LOUT2MUTE
0
Left speaker output mute:
0 = Normal operation
1 = Mute
Analogue
Outputs
5:0
LOUT2VOL
111001
Left speaker output volume:
000000 = -57dB
...
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
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
...
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.
00
Reserved
8:7
6
OUT3MUTE
5:4
w
Analogue
Outputs
PP, Rev 3.1, February 2007
77
WM8986
REGISTER
ADDRESS
57 (39h)
61 (39h)
Pre-Production
BIT
LABEL
DEFAULT
DESCRIPTION
REFER TO
3
OUT4_2OUT3
0
OUT4 mixer output to OUT3
0 = disabled
1= enabled
Analogue
Outputs
2
BYPL2OUT3
0
Left PGA output to OUT3
0 = disabled
1= enabled
Analogue
Outputs
1
LMIX2OUT3
0
Left DAC 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
HALFSIG
0
0=OUT4 normal output
1=OUT4 attenuated by 6dB
Analogue
Outputs
4
LMIX2OUT4
0
Left DAC 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 PGA output to OUT4
0 = disabled
1= enabled
Analogue
Outputs
1
RMIX2OUT4
0
Right DAC mixer to OUT4
0 = disabled
1= enabled
Analogue
Outputs
0
RDAC2OUT4
1
Right DAC output to OUT4
0 = disabled
1= enabled
Analogue
Outputs
8
0
Global bias control
0 = normal
1 = 0.5x
Bias Control
7:0
0000000
Reserved
w
PP, Rev 3.1, February 2007
78
WM8986
Pre-Production
DAC DIGITAL FILTER CHARACTERISTICS
PARAMETER
Passband
TEST CONDITIONS
MIN
+/- 0.035dB
0
-6dB
TYP
+/-0.035
Stopband
UNIT
0.5fs
Passband Ripple
Stopband Attenuation
MAX
0.454fs
dB
0.546fs
f > 0.546fs
Group Delay
-55
dB
29/fs
Table 43 DAC 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
w
PP, Rev 3.1, February 2007
79
WM8986
Pre-Production
DAC FILTER RESPONSES
3.05
0
3
-20
2.95
-40
2.9
Response (dB)
Response (dB)
20
-60
-80
-100
2.85
2.8
2.75
-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 36 DAC Digital Filter Frequency Response
(128xOSR)
0.25
0.3
0.35
0.4
0.45
0.5
0.45
0.5
Figure 37 DAC Digital Filter Ripple (128xOSR)
3.05
20
0
3
-20
2.95
-40
2.9
Response (dB)
Response (dB)
0.2
Frequency (fs)
Frequency (fs)
-60
-80
-100
2.85
2.8
2.75
-120
2.7
-140
2.65
2.6
-160
0
0.5
1
1.5
2
2.5
Frequency (fs)
Figure 38 DAC Digital Filter Frequency Response (64xOSR)
w
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
Frequency (fs)
Figure 39 DAC Digital Filter Ripple (64xOSR)
PP, Rev 3.1, February 2007
80
WM8986
Pre-Production
5-BAND EQUALISER
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
The WM8986 has a 5-band equaliser which can be applied to either the ADC path or the DAC path.
The plots from Figure 40 to Figure 53 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
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
-15
-1
10
5
Figure 40 EQ Band 1 Low Frequency Shelf Filter Cut-offs
15
15
10
10
5
5
0
-5
-10
-10
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
Figure 42 EQ Band 2 – Peak Filter Centre Frequencies,
EQ2BW=0
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
0
-5
-15
-1
10
10
Figure 41 EQ Band 1 Gains for Lowest Cut-off Frequency
Magnitude (dB)
Magnitude (dB)
0
-15
-1
10
Figure 43
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
EQ Band 2 – Peak Filter Gains for Lowest Cut-off
Frequency, EQ2BW=0
15
10
Magnitude (dB)
5
0
-5
-10
-15
-2
10
10
-1
10
0
1
10
Frequency (Hz)
10
2
10
3
10
4
Figure 44 EQ Band 2 – EQ2BW=0, EQ2BW=1
w
PP, Rev 3.1, February 2007
81
Pre-Production
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
WM8986
0
0
-5
-5
-10
-10
-15
-1
10
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
-15
-1
10
Figure 45 EQ Band 3 – Peak Filter Centre Frequencies, EQ3BFigure 46
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
EQ Band 3 – Peak Filter Gains for Lowest Cut-off
Frequency, EQ3BW=0
15
10
Magnitude (dB)
5
0
-5
-10
-15
-2
10
10
-1
10
0
1
10
Frequency (Hz)
10
2
10
3
10
4
Figure 47 EQ Band 3 – EQ3BW=0, EQ3BW=1
w
PP, Rev 3.1, February 2007
82
WM8986
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
Pre-Production
0
0
-5
-5
-10
-10
-15
-1
10
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
-15
-1
10
5
Figure 48 EQ Band 4 – Peak Filter Centre Frequencies, EQ3BFigure 49
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
EQ Band 4 – Peak Filter Gains for Lowest Cut-off
Frequency, EQ4BW=0
15
10
Magnitude (dB)
5
0
-5
-10
-15
-2
10
10
-1
10
0
1
10
Frequency (Hz)
10
2
10
3
10
4
15
15
10
10
5
5
Magnitude (dB)
Magnitude (dB)
Figure 50 EQ Band 4 – EQ3BW=0, EQ3BW=1
0
0
-5
-5
-10
-10
-15
-1
10
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
Figure 51 EQ Band 5 High Frequency Shelf Filter Cut-offs
w
-15
-1
10
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
Figure 52 EQ Band 5 Gains for Lowest Cut-off Frequency
PP, Rev 3.1, February 2007
83
WM8986
Pre-Production
Figure 53 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
10
0
10
1
2
10
Frequency (Hz)
10
3
10
4
10
5
Figure 53 Cumulative Frequency Boost/Cut
w
PP, Rev 3.1, February 2007
84
WM8986
Pre-Production
APPLICATIONS INFORMATION
RECOMMENDED EXTERNAL COMPONENTS
Figure 54 External Component Diagram
Notes:
1.
When operating LOUT2 and ROUT2 in class D mode, it is recommended that LC filtering is placed as close to the
LOUT2 and ROUT2 pins as possible. Low ESR components should be used for maximum efficiency. It is
recommended that a filter, consisting of a 33µH inductor and a 220nF capacitor, is used for optimal performance.
2.
The addition of ferrite beads to the outputs of LOUT2 and ROUT2 will suppress any potential interference noise
produced by the class D switching clocks.
w
PP, Rev 3.1, February 2007
85
WM8986
Pre-Production
PACKAGE DIAGRAM
DM043.F
FL: 28 PIN COL QFN PLASTIC PACKAGE 4 X 4 X 0.75 mm BODY, 0.45 mm LEAD PITCH
DETAIL 1
D
28
22
21
1
INDEX AREA
(D/2 X E/2)
4
A
E
SEE DETAIL 2
15
7
2X
8
14
1
bbb M C A B
b
e
2X
aaa C
aaa C
TOP VIEW
BOTTOM VIEW
DETAIL 1
DETAIL 2
A
0.08 C
C
5
A1
SIDE VIEW
PIN 1
IDENTIFICATION
0.150MM SQUARE
L
Datum
L1
0.275MM
DETAIL 2
SEATING PLANE
0.275MM
1
ccc C
A3
Terminal
tip
e/2
e
R
W
T
A3
H
G
b
Exposed lead
DETAIL 2
Symbols
A
A1
A3
b
D
E
e
G
H
L
L1
T
W
MIN
0.725
0
0.18
3.95
3.95
Dimensions (mm)
NOM
MAX
NOTE
0.75
0.775
0.02
0.05
0.203 REF
1
0.28
0.23
4.00
4.00
0.45 BSC
0.535 REF
0.100 REF
0.40 REF
0.05 REF
0.100 REF
0.230 REF
4.05
4.05
7
Tolerances of Form and Position
aaa
bbb
ccc
REF:
0.15
0.10
0.10
JEDEC, MO-220
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 VGGD-2.
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 APPLICATIONS NOTE WAN_0118 FOR FURTHER INFORMATION REGARDING PCB FOOTPRINTS AND QFN PACKAGE SOLDERING.
7. DEPENDING ON THE METHOD OF LEAD TERMINATION AT THE EDGE OF THE PACKAGE, PULL BACK (L1) MAY BE PRESENT.
8. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE.
w
PP, Rev 3.1, February 2007
86
Pre-Production
WM8986
IMPORTANT NOTICE
Wolfson Microelectronics plc (“Wolfson”) products and services are sold subject to Wolfson’s terms and conditions of sale,
delivery and payment supplied at the time of order acknowledgement.
Wolfson warrants performance of its products to the specifications in effect at the date of shipment. Wolfson reserves the
right to make changes to its products and specifications or to discontinue any product or service without notice. Customers
should therefore obtain the latest version of relevant information from Wolfson to verify that the information is current.
Testing and other quality control techniques are utilised to the extent Wolfson deems necessary to support its warranty.
Specific testing of all parameters of each device is not necessarily performed unless required by law or regulation.
In order to minimise risks associated with customer applications, the customer must use adequate design and operating
safeguards to minimise inherent or procedural hazards. Wolfson is not liable for applications assistance or customer
product design. The customer is solely responsible for its selection and use of Wolfson products. Wolfson is not liable for
such selection or use nor for use of any circuitry other than circuitry entirely embodied in a Wolfson product.
Wolfson’s products are not intended for use in life support systems, appliances, nuclear systems or systems where
malfunction can reasonably be expected to result in personal injury, death or severe property or environmental damage.
Any use of products by the customer for such purposes is at the customer’s own risk.
Wolfson does not grant any licence (express or implied) under any patent right, copyright, mask work right or other
intellectual property right of Wolfson covering or relating to any combination, machine, or process in which its products or
services might be or are used. Any provision or publication of any third party’s products or services does not constitute
Wolfson’s approval, licence, warranty or endorsement thereof. Any third party trade marks contained in this document
belong to the respective third party owner.
Reproduction of information from Wolfson datasheets is permissible only if reproduction is without alteration and is
accompanied by all associated copyright, proprietary and other notices (including this notice) and conditions. Wolfson is
not liable for any unauthorised alteration of such information or for any reliance placed thereon.
Any representations made, warranties given, and/or liabilities accepted by any person which differ from those contained in
this datasheet or in Wolfson’s standard terms and conditions of sale, delivery and payment are made, given and/or
accepted at that person’s own risk. Wolfson is not liable for any such representations, warranties or liabilities or for any
reliance placed thereon by any person.
ADDRESS:
Wolfson Microelectronics plc
Westfield House
26 Westfield Road
Edinburgh
EH11 2QB
United Kingdom
Tel :: +44 (0)131 272 7000
Fax :: +44 (0)131 272 7001
Email :: [email protected]
w
PP, Rev 3.1, February 2007
87