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DESCRIPTION
The WM8955L is a low power, high quality stereo DAC with
integrated headphone and loudspeaker amplifiers, designed to
reduce external component requirements in portable digital
audio applications.
The on-chip headphone amplifiers can deliver 40mW into a 16Ω
load. Advanced on-chip digital signal processing performs bass
and treble tone control.
The WM8955L can operate as a master or a slave, and
includes an on-chip PLL. It can use most master clock
frequencies commonly found in portable systems, including
USB, GSM, CDMA or PDC clocks, or standard 256f
s
clock
rates. Different audio sample rates such as 48kHz, 44.1kHz,
8kHz and many others are supported.
The WM8955L operates on supply voltages from 1.8V up to
3.6V, although the digital core can operate on a separate supply
down to 1.42V, saving power. Different sections of the chip can
also be powered down under software control.
The WM8955L is supplied in a very small and thin 5x5mm QFN
package, ideal for use in hand-held and portable systems.
WM8955L
Stereo DAC For Portable Audio Applications
FEATURES
•
•
•
•
•
•
•
•
•
•
•
DAC SNR 98dB, THD -86dB (‘A’ weighted @ 48kHz, 3.3V)
On-chip 400mW BTL Speaker Driver (mono)
On-chip Headphone Driver
- 40mW output power on 16Ω / 3.3V
- SNR 96dB, THD –79dB at 20mW with 16Ω load
Stereo and Mono Line-in mix into DAC output
Separately Mixed Stereo and Mono Outputs
Digital Tone Control and Bass Boost
Low Power
- Down to 7mW for stereo playback (1.8V / 1.5V supplies)
- 10µW Shutdown Mode
Low Supply Voltages
- Analogue and Digital I/O: 1.8V to 3.6V
- Digital core: 1.42V to 3.6V
Master clocks supported: GSM, CDMA, PDC, USB or
standard audio clocks
Audio sample rates supported: 8, 11.025, 12, 16, 22.05, 24,
32, 44.1, 48, 88.2, 96kHz
32-pin QFN package, 5x5x0.9mm size, 0.5mm lead pitch
APPLICATIONS
•
•
Smartphone / Multimedia Phone
Digital Audio Player
BLOCK DIAGRAM
WOLFSON MICROELECTRONICS plc
www.wolfsonmicro.com
Production Data, December 2004, Rev 4.1
Copyright
2004
Wolfson Microelectronics plc
WM8955L
TABLE OF CONTENTS
Production Data
DESCRIPTION .......................................................................................................1
FEATURES.............................................................................................................1
APPLICATIONS .....................................................................................................1
BLOCK DIAGRAM .................................................................................................1
TABLE OF CONTENTS .........................................................................................2
PIN CONFIGURATION...........................................................................................3
ORDERING INFORMATION ..................................................................................3
PIN DESCRIPTION ................................................................................................4
RECOMMENDED OPERATING CONDITIONS .....................................................5
ELECTRICAL CHARACTERISTICS ......................................................................6
TERMINOLOGY............................................................................................................. 7
OUTPUT PGA’S LINEARITY ......................................................................................... 8
HEADPHONE OUTPUT THD VERSUS POWER........................................................... 9
POWER CONSUMPTION ....................................................................................10
SIGNAL TIMING REQUIREMENTS .....................................................................11
SYSTEM CLOCK TIMING............................................................................................ 11
AUDIO INTERFACE TIMING – MASTER MODE ......................................................... 11
AUDIO INTERFACE TIMING – SLAVE MODE ............................................................ 12
CONTROL INTERFACE TIMING – 3-WIRE MODE ..................................................... 12
CONTROL INTERFACE TIMING – 2-WIRE MODE ..................................................... 13
DEVICE DESCRIPTION.......................................................................................14
INTRODUCTION.......................................................................................................... 14
SIGNAL PATH ............................................................................................................. 14
LINE INPUTS AND OUTPUT MIXERS ........................................................................ 18
ANALOGUE OUTPUTS ............................................................................................... 21
DIGITAL AUDIO INTERFACE...................................................................................... 25
MASTER CLOCK AND PHASE LOCKED LOOP ......................................................... 28
AUDIO SAMPLE RATES.............................................................................................. 30
CONTROL INTERFACE .............................................................................................. 32
POWER SUPPLIES ..................................................................................................... 33
POWER MANAGEMENT ............................................................................................. 34
REGISTER MAP...................................................................................................36
DIGITAL FILTER CHARACTERISTICS ...............................................................37
TERMINOLOGY........................................................................................................... 37
DAC FILTER RESPONSES ......................................................................................... 37
APPLICATIONS INFORMATION .........................................................................39
RECOMMENDED EXTERNAL COMPONENTS........................................................... 39
LINE OUTPUT CONFIGURATION............................................................................... 40
HEADPHONE OUTPUT CONFIGURATION ................................................................ 41
SPEAKER OUTPUT CONFIGURATION...................................................................... 41
PACKAGE DIMENSIONS ....................................................................................42
IMPORTANT NOTICE ..........................................................................................43
ADDRESS:................................................................................................................... 43
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Production Data
WM8955L
PIN CONFIGURATION
ORDERING INFORMATION
ORDER CODE
WM8955LEFL
WM8955LEFL/R
TEMPERATURE
RANGE
-25°C to +85°C
-25°C to +85°C
PACKAGE
32-pin QFN (5x5x0.9mm)
32-pin QFN (5x5x0.9mm)
(tape and reel)
32-pin QFN (5x5x0.9mm)
(lead free)
32-pin QFN (5x5x0.9mm)
(lead free, tape
and reel)
MOISTURE SENSITIVITY
LEVEL
MSL1
MSL1
PEAK SOLDERING
TEMPERATURE
260
o
C
260
o
C
260
o
C
260
o
C
WM8955LSEFL
-25°C to +85°C
MSL1
WM8955LSEFL/R
-25°C to +85°C
MSL1
Note:
Reel quantity = 3,500
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WM8955L
PIN DESCRIPTION
PIN NO
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
NAME
MCLK
DCVDD
DBVDD
DGND
BCLK
DACDAT
DACLRC
CLKOUT
PLLGND
MONOOUT
OUT3
ROUT1
LOUT1
HPGND
ROUT2
LOUT2
HPVDD
AVDD
AGND
VREF
VMID
NC
HPDETECT
NC
MONOIN-
MONOIN+
LINEINR
LINEINL
MODE
CSB
SDIN
SCLK
TYPE
Digital Input
Supply
Supply
Supply
Digital Input / Output
Digital Input
Digital Input / Output
Digital Output
Supply
Analogue Output
Analogue Output
Analogue Output
Analogue Output
Supply
Analogue Output
Analogue Output
Supply
Supply
Supply
Analogue Output
Analogue Output
No Connect
Logic Input
No Connect
Analogue Input
Analogue Input
Analogue Input
Analogue Input
Digital Input
Digital Input
Digital Input/Output
Digital Input
Master Clock
Digital Core Supply
Digital Buffer (I/O) Supply
DESCRIPTION
Production Data
Digital Ground (return path for both DCVDD and DBVDD)
Audio Interface Bit Clock
DAC Digital Audio Data
Audio Interface Left / Right Clock
Buffered Clock Output (from MCLK or internal PLL)
Internally connected to AGND. Connect this pin to AGND externally
for best PLL performance, or leave floating.
Mono Output
Output 3 (can be used as Headphone Pseudo Ground)
Right Output 1 (Line or Headphone)
Left Output 1 (Line or Headphone)
Supply for Analogue Output Drivers (LOUT1/2, ROUT1/2)
Right Output 1 (Line or Headphone or Speaker)
Left Output 1 (Line or Headphone or Speaker)
Supply for Analogue Output Drivers (LOUT1/2, ROUT1/2,
MONOUT)
Analogue Supply
Analogue Ground (return path for AVDD)
Reference Voltage Decoupling Capacitor
Midrail Voltage Decoupling Capacitor
No Internal Connection
Headphone / Speaker switch (referred to AVDD)
No Internal Connection
Negative end of MONOIN+, for differential mono signals
Analogue Line-in to mixers (mono channel)
Analogue Line-in to mixers (right channel)
Analogue Line-in to mixers (left channel)
Control Interface Selection
Chip Select / Device Address Selection
Control Interface Data Input / 2-wire Acknowledge output
Control Interface Clock Input
Note:
It is recommended that the QFN ground paddle should be connected to analogue ground on the application PCB.
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Production Data
WM8955L
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
Supply voltages
Voltage range digital inputs
Voltage range analogue inputs
Operating temperature range, T
A
Storage temperature after soldering
Notes
1.
2.
Analogue and digital grounds must always be within 0.3V of each other.
All digital and analogue supplies are completely independent from each other.
MIN
-0.3V
DGND -0.3V
AGND -0.3V
-25°C
-65°C
MAX
+3.63V
DBVDD +0.3V
AVDD +0.3V
+85°C
+150°C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Digital supply range (Core)
Digital supply range (Buffer)
Analogue supplies range
Ground
SYMBOL
DCVDD
DBVDD
AVDD, HPVDD
DGND, AGND, HPGND
TEST CONDITIONS
MIN
1.42
1.8
1.8
TYP
2.0
2.0
2.0
0
MAX
3.6
3.6
3.6
UNIT
V
V
V
V
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