DATASHEET SEARCH SITE | WWW.ALLDATASHEET.COM
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 12
Technical content
Stereo Headphone Driver with Wolfson Ambient Noise Cancellation WOLFSON MICROELECTRONICS plc Product Brief, September 2013, Rev 4.1 Copyright 2013 Wolfson Microelectronics plc
DESCRIPTION
The WM2002 is a low power, high quality stereo headphone driver, delivering Wolfson’s patented ambient noise cancellation. The WM2002 supports analogue playback or voice input, and analogue microphones for noise cancellation. Designed for incorporation within a stand-alone headset or headphone, the Wolfson ANC noise cancellation engine performs ambient noise cancellation during a voice call or during music playback. The WM2002 provides integrated power management, comprising a DC-DC converter, Charge Pump and LDO Regulators. Different power supply configurations can be supported, including operation from a single cell AAA or AA battery, and other configurations using externally regulated supplies. System clocking is achieved usi ng a crystal-controlled on-chip oscillator. An external clock can be connected directly, if available. The WM2002 is configured using programmable settings stored in an integrated non-volatile memory. The configuration stored in the OTP memory is enabled automatically at start-up. If required, the WM2002 can also be configured using register control accessed using a 2-wire serial control interface.
FEATURES
Wolfson Ambient Noise Cancellation (ANC) - >30dB (peak), 25dB (typical ) ambient noise reduction* - Wide noise cancellation bandwidth (40Hz to 4kHz)* - * depending on acoustic configuration - Up to 3 banks of ANC coefficients can be programmed to support different operating conditions Audio inputs - Up to 10 analogue noise cancellation microphones - 2 single-ended or 1 differential line input per channel Headphone driver (LDO4VOUT = 1.8V) - 45mW per channel into 16 load - 22mW per channel into 32 load - Single-ended or differential (BTL) drive configuration - -82dB THD+N for differential (BTL) drive Integration - On-chip DC-DC boost conver ter, charge-pump and LDOs - Flexible power supply opti ons, including single cell batter y (1 x AAA battery) - Internal crystal oscillator Miscellaneous - Monitor pin to select mute / talk-through modes - LED driver - Tone generator for audible status indication - Pop and click noise protection circuit - RFI suppression - 48-pin QFN package (7 x 7 x 0.75mm, 0.5mm pitch)
APPLICATIONS
“Pod-style” stereo ear-buds, headsets, headphones with ANC “Supra-Aural” stereo headphones with ANC Mono/Stereo Bluetooth headsets with ANC
w Product Brief, September 2013, Rev 4.1 BLOCK DIAGRAM
w Product Brief, September 2013, Rev 4.1 PIN CONFIGURATION
ORDERING INFORMATION
o C to +85 o C 48-pin QFN (Pb-free) MSL3 260 o C WM2002GEFL/RV -40 o C to +85 o C 48-pin QFN (Pb-free, tape and reel) MSL3 260 o C Note: Reel quantity = 2,200
w Product Brief, September 2013, Rev 4.1 PIN DESCRIPTION A description of each pin on the WM2002 is provided below. Note that, where multiple pins share a common name (eg. DGND), these pins should be tied together on the PCB. PIN NAME TYPE DESCRIPTION
1 LED Analogue Output Status LED output
2 DGND Supply Digital supplies ground
3 MON Digital Input Digital cont rol input (changes ANC filter characteristics, selects mute
or talk-through mode)
4 ADDR Digital Input Control interface address select
5 SDA Digital Input/Output Control interface data input / output
6 SCLK Digital Input Control interface clock input
7 LDO1VDD Supply LDO1 supply input
8 LDO1VOUT Analogue Output /
LDO1 output / Digital core supply
9 MICVDD Supply MICBIAS supply input
10 MICBIAS Analogue Output Bias supply for external microphones
11 LDO3VOUT Analogue Output /
LDO3 output / Analogue supply
12 AGND Supply Analogue supplies ground
13 MICLN Analogue Input Left channel invert ing analogue noise cancelling mic input
14 MICLP Analogue Input Left channel non-invert ing analogue noise cancelling mic input
15 MICRP Analogue Input Right channel non-inve rting analogue noise cancelling mic input
16 MICRN Analogue Input Right channel invert ing analogue noise cancelling mic input
17 INLP Analogue Input Left channel non-in verting differential line input
18 INLN Analogue Input Left channel inverting differential line input
(can be grounded for single-ended operation)
19 INRN Analogue Input Right channel in verting differential line input
(can be grounded for single-ended operation)
20 INRP Analogue Input Right channel non- inverting differential line input
21 VMIDC Analogue I/O Midrail volt age capacitor connection point
22 LDO4VOUT Analogue Output /
LDO4 output / Headphone driver supply
23 HPOUTLP Analogue Output Left headphone non-inverting output
24 HPOUTLN Analogue Output Left headphone inverting output
25 HPGND Supply Headphone driver ground
26 HPOUTRN Analogue Output Right headphone inverting output
27 HPOUTRP Analogue Output Right headphone non-inverting output
28 CPVOUT Analogue Output Charge pump output
29 BATTVDD Supply DC1 boost converter supply input / Battery supply
30 CFB2 Analogue I/O Charge pump flyback capacitor connection
31 CFB1 Analogue I/O Charge pump flyback capacitor connection
32 CPGND Supply Charge pump ground
33 DC1LX Analogue I/O DC1 boost conv erter inductor connection pin
34 DC1VOUT Analogue Output DC1 boost converter output
35 SYSVDD Supply System supply input
36 XTO Analogue Output Crystal drive output
37 XTI Analogue Input Crystal drive input or CMOS clock input
38 DGND Supply Digital supplies ground
39 PROGVDD Supply OTP Memory programming supply - normally tied to DGND
40 LDO2VOUT Analogue Output /
LDO2 output / OTP memory supply
41 VREFC Analogue I/O Voltage refe rence capacitor connection
w Product Brief, September 2013, Rev 4.1 PIN NAME TYPE DESCRIPTION
42 IREFR Analogue
Current reference resistor connection
43 DBVDD Supply Digital buffer supply
44 DNC n/a Do Not Connect
45 DGND Supply Digital supplies ground
46 DGND Supply Digital supplies ground
47 DGND Supply Digital supplies ground
48 DGND Supply Digital supplies ground
Absolute Maximum Ratings are stress ratings only. Pe rmanent damage to the device ma y be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed perfo rmance specifications are given under Electrical Characteristics at the test conditions specified. ESD Sensitive Device. This device is manufactur ed 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-020 for Moisture Sensitivity to determine acceptable storage conditions prior to surface mount assembly. These levels are: MSL1 = unlimited floor life at <30C / 85% Relative Humidity. Not normally stored in moisture barrier bag. MSL2 = out of bag storage for 1 year at <30C / 60% Relative Humidity. Supplied in moisture barrier bag. MSL3 = out of bag storage for 168 hours at <30C / 60% Relative Humidity. Supplied in moisture barrier bag. The Moisture Sensitivity Level for each package type is specified in “Ordering Information”. CONDITION MIN MAX BATTVDD -0.3V +1.8V SYSVDD, MICVDD, LDO1VDD, DBVDD -0.3V +3.6V PROGVDD -0.3V +6.75V Voltage range digital inputs DGND - 0.3V DBVDD + 0.3V Voltage range analogue inputs AGND - 0.3V LDO3VOUT + 0.25V Operating temperature range, TA -40ºC +85ºC Storage temperature after soldering -65ºC +150ºC
w Product Brief, September 2013, Rev 4.1 RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN TYP MAX UNIT DC Boost converter input (see Note 5) BATTVDD 0.9 1.6 V Digital buffer supply DBVDD 1.4 2.5 V MICBIAS supply (see Note 4) MICVDD 2.3 2.8 3.6 V Digital core supply (LDO1) LDO1VDD 1.2 3.3 V System supply (LDO2, LDO3 and LDO4) SYSVDD 2.1 2.1 3.3 V OTP Memory programming supply (see Note 3) PROGVDD 6.25 6.5 6.75 V Ground DGND, AGND, CPGND, HPGND 0 V Notes: 1. Analogue and digital grounds must always be within 0.3V of each other. 2. All supplies are completely independent from each other (i.e. not internally connected). 3. The OTP Memory programming supply (PROGVDD) shoul d only be present when programming the OTP. At other times, this pin should be tied to DGND. 4. MICVDD must be at least 300mV higher than the selected MICBIAS output voltage. 5. When the Charge Pump is enabled, the maximum BATTVDD voltage will depend on the programmable voltage DC1VOUT. The combined voltage BATTVDD + DC1VOUT must not exceed 3.6V. TYPICAL APPLICATIONS A typical application circuit is illustrated in Figur e 1, showing the line inputs, ANC microphone inputs, and stereo headphone output. Figure 1 Typical Application
w Product Brief, September 2013, Rev 4.1 WOLFSON AMBIENT NOISE CANCELLATION (ANC) The Wolfson (ANC) engine within the WM2002 improves the intelligibility of a voice call by using destructive interference to reduce the acoustic energy of the ambient sound. The ANC engine is configured using parameters that are determined during product development and programmed on integrated OTP memory. The configur ation settings are spec ific to the acoustic properties of the target application. The primary acoustic elements in an application are typically the microphones and the speaker, but other components such as the plastics and the PCBs also have significant importance to the acoustic coefficient data. Note that the WM2002 configuration paramet ers are determined during development and are programmed in the OTP memory during production calibration. These parameters are application- specific, and must be recalculated following any change in the design of the acoustic elements of that application. Any mismatch between the acoustic coe fficient data and the target application will give inferior ANC performance. The ANC engine employs digital circ uits to process the ambient noise (microphone) signals; these inputs are digitized by two Anal ogue to Digital Converters (ADCs), then filtered and processed in accordance with the acoustic parameters progra mmed into the WM2002. The noise cancellation signals are then output via two Digital to Analogue Converters (DACs) and mixed with the received voice or audio playback (line) signals. The ANC engine can support multiple noise canc ellation filter coefficients, to enable best performance under different ambient noise conditi ons and different audio pl ayback conditions. Other user-selectable options are also available, such as mute or talk-through modes. A high pass filter provides rejection of wind noi se and other low frequency signals .Noise cancellation is applied selectively to different audio frequency bands. A configurable low frequency limiter protects the loudspeaker from excessive signal levels, and ensures that the ANC algorithms deliver noise reduction in the most sensitive frequency bands, wi thout introducing distortion in other frequency bands. The ANC engine is adaptive to different ambient noise levels in order to provide the most natural sound at the headphone audio output. The integrated noise gate automatically mutes the noise cancelling input at low ambient noise levels; this ensures that the noise c ancellation performance is optimised across a wide range of input signal conditions. The noise gate threshold level, attack time and decay time are all configurable. The various functions of ANC engine, as descri bed above, combine to form a comprehensive, stand- alone noise-cancelling product.
w Product Brief, September 2013, Rev 4.1 RECOMMENDED EXTERNAL COMPONENTS WM2002 LDO3VOUT LDO2VOUT LDO4VOUT MICLP MICBIAS XTI XTO 2.2 F2.2 F2.2 F2.2 F External 2.1V supply 4.7 F VREFC100nF MICLN MICRP 4.7 F MICRN 3.3k 3.3k ANC Microphone Inputs INLP 2.2 F INLN INRP 2.2 F INRN Line Inputs VMIDC4.7 F 18pF 18pF 12.288MHz LDO1VOUT LDO1VDD MICVDD DBVDD SYSVDD 2.2 F2.2 F2.2 F CFB1 BATTVDD DC1LX DC1VOUT CPVOUT CPGND CFB2 IREFR 100k PROGVDD 100k F 4.7 F 27pF 4.7 F 4.7 F 300 LED DBVDD 10k DMICBVDD MON Control Interface DBVDD ADDR 10k SCLK SDA HPOUTLP HPOUTRN HPOUTLN HPOUTRP Stereo Headphone DGND AGND HPGND 100nF 2.2 F External 2.8V supply Pre- Amp* Pre- Amp* * see reference schematics for full pre-amp details Figure 2 External Components Diagram
w Product Brief, September 2013, Rev 4.1 The recommended external components are illustrat ed in Figure 2. This shows the external connections to the audio inputs/outputs, clocking crystal and power management circuits. Note that Figure 2 shows the recommended device confi guration for use with a 2.5V external supply. In this example, the DC1 boost converter and the Charge Pump are not used. In other cases where the DC1 boost converter and Charge Pump circuits are used (for example, when the WM2002 is powered from a single AAA batte ry), some additional external components are required, as shown in Figure 3. WM2002 LDO3VOUT LDO2VOUT LDO4VOUT 2.2 F2.2 F2.2 F2.2 F VREFC100nF VMIDC4.7 F LDO1VOUT SYSVDD CFB1 BATTVDD DC1LX DC1VOUT CPVOUT CPGND CFB2 IREFR 100k PROGVDD 100k F 1.2V Battery Supply 1.5 H MICVDD 2.2 F 100nF DGND AGND HPGND LDO1VDD DBVDD 2.2 F2.2 F4.7 F Figure 3 External Components - DC1 Boost Converter and Charge Pump Note that an external pre-amp is recommended fo r microphone input (instead of the direct connection shown in Figure 2). Additional options for noise improvement, battery control, and for different input or output component configurations are noted in the typical application circuit schematics. Please contact your local Wolfson representative for details.
w Product Brief, September 2013, Rev 4.1 PACKAGE DIMENSIONS DM079.AFL: 48 PIN QFN PLASTIC PACKAGE 7 X 7 X 0.75 mm BODY, 0.50 mm LEAD PITCH INDEX AREA (D/2 X E/2) TOP VIEW Caaa2 X E2/2 L D2/2 Caaa2 X 37 48 D E e PIN 1 A Symbols Dimensions (mm) MIN NOM MAX NOTE A b D E e L 0.75 0.300.250.20
7.00 BSC
5.755.655.55
0.5 BSC
5.65 5.755.55 0.35 0.4 0.45 0 0.035 0.05
0.203 REF
NOTES: 1. DIMENSION b APPLIED TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.15 mm AND 0.30 mm FROM TERMINAL TIP. 2. ALL DIMENSIONS ARE IN MILLIMETRES 3. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95-1 SPP-002. 4. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS. 5. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE. 6. REFER TO APPLICATIONS NOTE WAN_0118 FOR FURTHER INFORMATION. JEDEC, MO-220 Tolerances of Form and Position aaa bbb ccc 0.10 0.08 0.10 REF EXPOSED GND PADDLE 0.7 0.8 A2 - 0.55 0.57 Cccc b C bbb (A3) CSEATING PLANE
w Product Brief, September 2013, Rev 4.1 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 t he date of shipment. Wolfson reserves the right to make changes to its products and s pecifications or to discontinue any produc t 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 app lications, the customer must use adequate design and operating safeguards to minimise inherent or proc edural hazards. Wolfson is not liable fo r applications assistance or customer product design. The customer is solely responsible for its se lection 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 re sult 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 pr ocess in which its products or services might be or are used. Any prov ision 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 per missible only if reproduction is without alteration and is accompanied by all associated copyright, proprietary and other not ices (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 giv en, and/or liabilities accepted by any pers on 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
Tel :: +44 (0)131 272 7000 Fax :: +44 (0)131 272 7001 Email :: sales@wolfsonmicro.com
w Product Brief, September 2013, Rev 4.1
REVISION HISTORY
DATE REV DESCRIPTION OF CHANGES PAGE CHANGED BY 28/05/10 1.0 Initial version PH 04/08/10 1.1 External components drawings updated. Ambient noise reduction and bandwidth figures updated. PH 19/01/12 4.0 Updates to all sections PH 10/09/13 4.1 Block Diagram corrected: ADC L changed to ADC R JMacD 01/10/13 4.1 Microphone pre-amp added to diagrams, Recommended mic input capacitor changed to 4.7uF. JMacD