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DESCRIPTION
The WM8350 is an integrated audio and power management
subsystem which provides a cost effective, single-chip solution
for portable audio and multimedia systems.
The integrated audio CODEC provides all the necessary
functions for high-quality stereo recording and playback.
Programmable on-chip amplifiers allow for the direct
connection of headphones and microphones with a minimum
of external components. A programmable low-noise bias
voltage is available to feed one or more electret microphones.
Additional audio features include programmable high-pass
filter in the ADC input path.
The WM8350 includes six programmable DC-DC converters,
four low-dropout (LDO) regulators and a current limit switch to
generate suitable supply voltages for each part of the system,
including the integrated audio CODEC as well as off-chip
components such as a digital core and I/O supplies, and LED
lighting. An additional on-chip regulator maintains the backup
power for always-on functions. The WM8350 can be powered
by a lithium battery, by a wall adaptor or USB.
An on-chip battery charger supports both trickle charging and
fast (constant current, constant voltage) charging of single-cell
lithium batteries. The charge current, termination voltage, and
charger time-out are programmable to suit different types of
batteries.
Internal power management circuitry controls the start-up and
shutdown sequencing of clocks and supply voltages. It also
detects and handles conditions such as under-voltage,
extreme temperatures, and deeply discharged or defective
batteries, with a minimum of software involvement.
Two programmable constant-current sinks are available for
driving LED strings, e.g. for display backlights or photo-flash
applications, in a highly power-efficient way. Additional RGB
LEDs can be driven through GPIO pins.
The WM8350 includes a 32.768kHz crystal oscillator, an
internal RC oscillator, a real-time clock (RTC) and an alarm
function capable of waking up the system. Internal circuitry
can generate all clock signals required to start up the device.
The master clock for the audio CODEC can be input directly,
or may be generated internally using an integrated, low power
Frequency Locked Loop (FLL).
To extend battery life, fine-grained power management
enables each function in the WM8350 to be independently
powered down through the control interface. The WM8350
forms part of the Wolfson AudioPlus
TM
series of audio and
power management solutions.
WM8350
Wolfson AudioPlus™ Stereo CODEC with Power Management
FEATURES
Stereo Hi-Fi CODEC
•
DAC SNR 95dB (‘A’ weighted @ 48kHz), THD –81dB
•
ADC SNR 95dB (‘A’ weighted @ 48kHz), THD –83dB
•
•
•
•
•
•
•
40mW on-chip headphone driver with ‘capless’ option
16Ω headphone load: THD -72dB, Po = 20mW
2 differential microphone inputs with low-noise bias
voltage and programmable preamps
Programmable high-pass filter for ADC
Microphone and Headphone detection
Auxiliary inputs for analogue signals
Sample rates: 8, 11.025, 16, 22.05, 24, 32, 44.1 or 48kHz
System Control
•
Support for 2-wire or 3-/4-wire Control Interface
•
Handles power sequencing, reset signals and fault
conditions
•
Autonomous power source selection (battery, wall adaptor
or USB bus)
•
Total current drawn from USB bus is limited to comply with
USB 2.0 standard and USB OTG supplement
Supply Generation
•
2 x DC-DC Buck Converters (0.85V - 3.4V, Up to 1A)
•
2 x DC-DC Buck Converters (0.85V - 3.4V, Up to 500mA)
•
2 x DC-DC Boost Converters (5V - 20V, 40 to 200mA)
•
4 x LDO voltage regulators (0.9V - 3.3V, 150mA)
LED Drivers
•
2 programmable constant-current sinks, suitable for
screen backlight or white LED photo flash
•
3 open-drain outputs for RGB LEDs
Battery Charger
•
Single-cell Li-Ion / Li-Pol battery charger
•
Thermal protection for charge control; temperature
monitoring available for thermal regulation
•
LED outputs to indicate charge status and fault conditions
Additional Features
•
•
•
•
•
•
“Always on” RTC with wake-up alarm
Watchdog timer
Up to 13 configurable GPIO pins
On-chip crystal oscillator and internal RC oscillator
Low power FLL supporting wide range of input clocks
7x7mm, 129 BGA package, 0.5mm ball pitch
APPLICATIONS
•
•
•
Portable Audio and Media players
Portable Navigation Devices
Portable systems powered by single-cell lithium batteries
WOLFSON MICROELECTRONICS plc
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Production Data, December 2010, Rev 4.3
Copyright
©2010
Wolfson Microelectronics plc
WM8350
TYPICAL APPLICATIONS
Production Data
The WM8350 is a complete audio and power management solution for portable media devices. The
device incorporates four programmable step-down switching regulators, two step-up switching
regulators, a full-featured battery charger, four Low Drop-Out (LDO) voltage regulators which can
also serve as hot-swap outputs, a backup supply regulator, two programmable white LED drivers, a
Real-Time Clock (RTC) alongside a 32.768kHz (32kHz) oscillator capable of operating from a backup
battery, a 12-bit auxiliary ADC for precise measurements, a ROM-programmable power management
state machine and numerous protection features all in a single 7x7mm BGA package. When only
battery power is available, a battery switch provides power to all switching regulators (and some
other internal modules). When external power is applied (eg. from USB or Wall adapter), the
WM8350 seamlessly transitions from battery power (a single-cell Lithium battery) to the applicable
external supply. The battery charger is then activated, all internal power for the device is drawn from
the appropriate external power source and the battery is disconnected from the load. Maximum
battery charge current and charge time are programmable. The USB power manager provides
accurate current limiting for the USB pin under all conditions. The hot-swap outputs (LDOs in current-
limited ‘Switch Mode’ operation) are ideal for powering memory cards and other devices that can be
inserted while the system is fully powered.
The integrated Hi-Fi stereo CODEC incorporates preamps and a low-noise bias voltage for
differential microphones, and flexible pseudo-differential drivers for headphone and differential/single-
ended line outputs. External component requirements are reduced as no separate microphone or
headphone amplifiers are required. Digital filter options are available in the ADC and DAC paths, to
cater for application filtering. The WM8350 is capable of operating without any external clock, as it
can derive all required clocks from its internal crystal oscillator, RC clock, and Frequency Locked
Loop. An external low jitter clock may be required in some applications for high performance audio.
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PD, December 2010, Rev 4.3
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Production Data
WM8350
BLOCK DIAGRAM
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PD, December 2010, Rev 4.3
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WM8350
TABLE OF CONTENTS
Production Data
DESCRIPTION ....................................................................................................... 1
FEATURES............................................................................................................. 1
APPLICATIONS ..................................................................................................... 1
TYPICAL APPLICATIONS ..................................................................................... 2
BLOCK DIAGRAM ................................................................................................. 3
TABLE OF CONTENTS ......................................................................................... 4
1
PIN CONFIGURATION .................................................................................. 9
2
ORDERING INFORMATION .......................................................................... 9
3
PIN DESCRIPTION ...................................................................................... 10
4
THERMAL CHARACTERISTICS ................................................................. 13
5
ABSOLUTE MAXIMUM RATINGS .............................................................. 14
6
RECOMMENDED OPERATING CONDITIONS ........................................... 15
7
ELECTRICAL CHARACTERISTICS ............................................................ 16
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
HI-FI AUDIO CODEC ......................................................................................... 16
DC-DC STEP UP CONVERTER ELECTRICAL CHARACTERISTICS ............... 18
DC-DC STEP DOWN CONVERTER ELECTRICAL CHARACTERISTICS ........ 19
LDO REGULATOR ELECTRICAL CHARACTERISTICS ................................... 21
BATTERY CHARGER........................................................................................ 22
CURRENT LIMIT SWITCH ................................................................................ 22
LED DRIVERS ................................................................................................... 23
GENERAL PURPOSE INPUTS / OUTPUTS (GPIO) ......................................... 23
DIGITAL INTERFACES ..................................................................................... 24
AUXILIARY ADC ............................................................................................ 24
8
9
9.1
9.2
TYPICAL POWER CONSUMPTION ............................................................ 25
TYPICAL PERFORMANCE DATA............................................................... 27
AUDIO CODEC.................................................................................................. 27
DC-DC CONVERTERS...................................................................................... 28
9.2.1
9.2.2
9.2.3
POWER EFFICIENCY ............................................................................................................. 28
OUTPUT VOLTAGE REGULATION ........................................................................................ 29
DYNAMIC OUTPUT VOLTAGE ............................................................................................... 30
9.3
LDO REGULATORS .......................................................................................... 31
10
SIGNAL TIMING REQUIREMENTS............................................................. 32
SYSTEM CLOCK TIMING .............................................................................. 32
AUDIO INTERFACE TIMING - MASTER MODE ............................................ 32
AUDIO INTERFACE TIMING - SLAVE MODE................................................ 33
AUDIO INTERFACE TIMING - TDM MODE ................................................... 34
CONTROL INTERFACE TIMING.................................................................... 35
GENERAL DESCRIPTION ............................................................................. 38
CONTROL INTERFACE MODES ................................................................... 38
2-WIRE SERIAL CONTROL MODE ............................................................... 39
3-WIRE SERIAL CONTROL MODE ............................................................... 42
4-WIRE SERIAL CONTROL MODE ............................................................... 43
REGISTER LOCKING .................................................................................... 44
SPECIAL REGISTERS ................................................................................... 44
CHIP ID ................................................................................................................................ 44
DEVICE INFORMATION ...................................................................................................... 44
PD, December 2010, Rev 4.3
4
10.1
10.2
10.3
10.4
10.5
11
CONTROL INTERFACE .............................................................................. 38
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.7.1
11.7.2
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Production Data
WM8350
12
CLOCKING, TIMING AND SAMPLE RATES .............................................. 45
GENERAL DESCRIPTION ............................................................................. 45
CLOCKING THE AUDIO CODEC ........................................................................................ 46
CLOCKING THE DC-DC CONVERTERS ............................................................................ 46
INTERNAL RC OSCILLATOR .............................................................................................. 46
12.1.1
12.1.2
12.1.3
12.1
12.2
12.3
CRYSTAL OSCILLATOR................................................................................ 46
CLOCKING AND SAMPLE RATES ................................................................ 47
SYSCLK CONTROL............................................................................................................. 49
ADC / DAC SAMPLE RATES............................................................................................... 50
BCLK CONTROL ................................................................................................................. 52
ADCLRCLK / DACLRCLK CONTROL ................................................................................. 54
OPCLK CONTROL .............................................................................................................. 55
SLOWCLK CONTROL ......................................................................................................... 55
EXAMPLE FLL CALCULATION ........................................................................................... 58
EXAMPLE FLL SETTINGS .................................................................................................. 59
12.3.1
12.3.2
12.3.3
12.3.4
12.3.5
12.3.6
12.4
FLL ................................................................................................................. 55
12.4.1
12.4.2
13
AUDIO CODEC SUBSYSTEM ..................................................................... 60
GENERAL DESCRIPTION ............................................................................. 60
AUDIO PATHS ............................................................................................... 61
ENABLING THE AUDIO CODEC ................................................................... 62
INPUT SIGNAL PATH .................................................................................... 63
MICROPHONE INPUTS ...................................................................................................... 63
ENABLING THE PRE-AMPLIFIERS .................................................................................... 64
SELECTING INPUT SIGNALS ............................................................................................. 65
CONTROLLING THE PRE-AMPLIFIER GAINS ................................................................... 66
MICROPHONE BIASING ..................................................................................................... 67
AUXILIARY INPUTS (IN3L AND IN3R) ................................................................................ 67
INPUT MIXERS .................................................................................................................... 69
ADC VOLUME CONTROL ................................................................................................... 72
ADC HIGH-PASS FILTER.................................................................................................... 72
DIGITAL SIDETONE ............................................................................................................ 73
DAC PLAYBACK VOLUME CONTROL ............................................................................... 76
DAC SOFT MUTE AND SOFT UN-MUTE............................................................................ 76
DAC DE-EMPHASIS ............................................................................................................ 77
DAC OUTPUT PHASE AND MONO MIXING ....................................................................... 78
DAC STOPBAND ATTENUATION ....................................................................................... 78
ENABLING THE ANALOGUE OUTPUTS ............................................................................ 79
OUTPUT MIXERS ................................................................................................................ 80
OUT1L AND OUT1R ............................................................................................................ 83
OUT2L AND OUT2R ............................................................................................................ 85
HEADPHONE OUTPUTS EXTERNAL CONNECTIONS ..................................................... 87
OUT3 AND OUT4 ................................................................................................................ 89
AUDIO DATA FORMATS ..................................................................................................... 91
AUDIO INTERFACE TDM MODE ........................................................................................ 94
TDM DATA FORMATS......................................................................................................... 94
LOOPBACK ......................................................................................................................... 96
13.1
13.2
13.3
13.4
13.4.1
13.4.2
13.4.3
13.4.4
13.4.5
13.4.6
13.4.7
13.5
13.6
13.7
ANALOGUE TO DIGITAL CONVERTER (ADC) ............................................. 71
DIGITAL MIXING ............................................................................................ 73
DIGITAL TO ANALOGUE CONVERTER (DAC) ............................................. 75
13.5.1
13.5.2
13.6.1
13.7.1
13.7.2
13.7.3
13.7.4
13.7.5
13.8
13.9
OUTPUT SIGNAL PATH ................................................................................ 79
ANALOGUE OUTPUTS .................................................................................. 83
13.8.1
13.8.2
13.9.1
13.9.2
13.9.3
13.9.4
13.10
DIGITAL AUDIO INTERFACE ........................................................................ 91
13.10.1
13.10.2
13.10.3
13.10.4
13.11
13.12
COMPANDING ............................................................................................... 97
ADDITIONAL CODEC FUNCTIONS ............................................................... 99
PD, December 2010, Rev 4.3
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