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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
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DAC SNR 95dB (‘A’ weighted @ 48kHz), THD –81dB
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ADC SNR 95dB (‘A’ weighted @ 48kHz), THD –83dB
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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
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Support for 2-wire or 3-/4-wire Control Interface
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Handles power sequencing, reset signals and fault
conditions
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Autonomous power source selection (battery, wall adaptor
or USB bus)
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Total current drawn from USB bus is limited to comply with
USB 2.0 standard and USB OTG supplement
Supply Generation
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2 x DC-DC Buck Converters (0.85V - 3.4V, Up to 1A)
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2 x DC-DC Buck Converters (0.85V - 3.4V, Up to 500mA)
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2 x DC-DC Boost Converters (5V - 20V, 40 to 200mA)
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4 x LDO voltage regulators (0.9V - 3.3V, 150mA)
LED Drivers
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2 programmable constant-current sinks, suitable for
screen backlight or white LED photo flash
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3 open-drain outputs for RGB LEDs
Battery Charger
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Single-cell Li-Ion / Li-Pol battery charger
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Thermal protection for charge control; temperature
monitoring available for thermal regulation
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LED outputs to indicate charge status and fault conditions
Additional Features
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“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
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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, February 2011, Rev 4.4
Copyright
©2011
Wolfson Microelectronics plc
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
