w WM9010 Low Power, Class G Stereo Headphone Driver DESCRIPTION FEATURES The WM9010 is a low power stereo headphone driver designed for mobile handset and portable media player (PMP) applications. Class G amplifier technology is used to achieve high power efficiency and low quiescent current. Stereo analogue inputs accept 1Vrms line level inputs; the Hi-Fi output drivers deliver up to 28mW into a 32 load. Active ground-loop feedback provides rejection of system-related ground noise. Hi-fi audio headphone drivers (104dB SNR - `A' weighted) Stereo analogue audio inputs Ground-referenced, cap-less headphone outputs Integrated charge pump and oscillator circuits Low quiescent current RF noise suppression Pop and click suppression 12-pin CSP package (1.84 x 1.34 x 0.7mm) An integrated charge pump circuit generates split-rail voltage supplies to power the ground-referenced headphone driver. APPLICATIONS The WM9010 incorporates Wolfson Silent SwitchTM technology to provide pop and click suppression whenever the WM9010 is enabled or disabled. Mobile Handsets Portable Media Players (PMP) Notebooks / Laptop computers LCD televisions The WM9010 is supplied in a 12-pin CSP package. ENA RF noise suppression GND VDD Pop and click suppression INL HPOUTL HPOUTFB HPOUTR INR Oscillator Charge Pump WOLFSON MICROELECTRONICS plc To receive regular email updates, sign up at http://www.wolfsonmicro.com/enews CPCA CPCB CPVOUTN CPVOUTP WM9010 Preliminary Technical Data, May 2010, Rev 2.0 Copyright 2010 Wolfson Microelectronics plc WM9010 Preliminary Technical Data TABLE OF CONTENTS DESCRIPTION ....................................................................................................... 1 FEATURES ............................................................................................................ 1 APPLICATIONS..................................................................................................... 1 TABLE OF CONTENTS ......................................................................................... 2 PIN CONFIGURATION .......................................................................................... 3 ORDERING INFORMATION .................................................................................. 3 PIN DESCRIPTION ................................................................................................ 3 ABSOLUTE MAXIMUM RATINGS ........................................................................ 4 RECOMMENDED OPERATING CONDITIONS ..................................................... 4 THERMAL PERFORMANCE ................................................................................. 5 ELECTRICAL CHARACTERISTICS ..................................................................... 6 TERMINOLOGY ............................................................................................................... 7 DEVICE DESCRIPTION ........................................................................................ 8 INTRODUCTION .............................................................................................................. 8 HEADPHONE DRIVER .................................................................................................... 8 CHARGE PUMP ............................................................................................................... 9 APPLICATIONS INFORMATION ........................................................................ 10 RECOMMENDED EXTERNAL COMPONENTS ............................................................ 10 PCB LAYOUT CONSIDERATIONS ............................................................................... 10 PACKAGE DIMENSIONS .................................................................................... 11 IMPORTANT NOTICE ......................................................................................... 12 ADDRESS: ..................................................................................................................... 12 w PTD, May 2010, Rev 2.0 2 WM9010 Preliminary Technical Data PIN CONFIGURATION The WM9010 is supplied in a 12-pin CSP format. The pin configuration is illustrated below, showing the top-down view from above the chip. ORDERING INFORMATION ORDER CODE TEMPERATURE RANGE PACKAGE MOISTURE SENSITIVITY LEVEL PEAK SOLDERING TEMPERATURE -40C to +85C 12-pin CSP (Pb-free, tape and reel) MSL1 260 C WM9010ECSN/R o Note: Reel quantity = 3500 PIN DESCRIPTION PIN NO NAME TYPE DESCRIPTION A1 INL Analogue Input Left channel analogue input A2 INR Analogue Input Right channel analogue input A3 VDD Supply Positive supply A4 GND Supply Ground B1 HPOUTFB Analogue Input HPOUTL and HPOUTR ground loop noise rejection feedback B2 ENA Digital Input Device Enable / Mute control B3 CPCA Analogue Output Charge pump fly-back capacitor pin B4 CPCB Analogue Output Charge pump fly-back capacitor pin C1 HPOUTL Analogue Output Left headphone output C2 HPOUTR Analogue Output Right headphone output C3 CPVOUTP Analogue Output Charge pump positive supply decoupling pin C4 CPVOUTN Analogue Output Charge pump negative supply decoupling pin w PTD, May 2010, Rev 2.0 3 WM9010 Preliminary Technical Data 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 <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. MIN MAX Supply voltage (VDD) CONDITION -0.3V 2.5V Voltage range digital input (ENA) -0.7V 3.3V Voltage range analogue inputs -0.7V VDD +0.7V Operating temperature range, TA -40C +85C Junction temperature, TJMAX -40C +150C Storage temperature after soldering -65C +150C RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN TYP MAX Supply Voltage VDD 1.71 1.8 2.0 V Logic 1 digital input (ENA) ENA 0.8 x VDD VDD 2.7 V Ground GND w 0 UNIT V PTD, May 2010, Rev 2.0 4 WM9010 Preliminary Technical Data THERMAL PERFORMANCE Thermal analysis should be performed in the intended application to prevent the WM9010 from exceeding maximum junction temperature. Several contributing factors affect thermal performance most notably the physical properties of the mechanical enclosure, location of the device on the PCB in relation to surrounding components and the number of PCB layers. Connecting the GND pin through thermal vias and into a large ground plane will aid heat extraction. Three main heat transfer paths exist to surrounding air as illustrated below in Figure 1: - Package top to air (radiation). - Package bottom to PCB (radiation). - Package pins to PCB (conduction). Figure 1 Heat Transfer Paths The temperature rise TR is given by TR = PD * JA - PD is the power dissipated in the device. - JA is the thermal resistance from the junction of the die to the ambient temperature and is therefore a measure of heat transfer from the die to surrounding air. JA is determined with reference to JEDEC standard JESD51-9. The junction temperature TJ is given by TJ = TA +TR, where TA is the ambient temperature. SYMBOL MIN Operating temperature range PARAMETER TYP MAX TA -40 85 C Operating junction temperature TJ -40 125 C Thermal Resistance JA TBD UNIT C/W Note: 1. Junction temperature is a function of ambient temperature and of the device operating conditions. The ambient temperature limits and junction temperature limits must both be observed. w PTD, May 2010, Rev 2.0 5 WM9010 Preliminary Technical Data ELECTRICAL CHARACTERISTICS Test Conditions o VDD = 1.8V, GND = 0V, Load resistance = 16, TA = +25 C, 1kHz signal unless otherwise stated. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Analogue Inputs (INL, INR) Single-ended input Maximum input signal level Input resistance VDD/1.8 Vrms 20 k TBD pF RL = 32; THD+N = 0.1% 27 mW RL = 32; THD+N = 1% 28 RL = 16; THD+N = 0.1% 31 Input capacitance Headphone Output Path (HPOUTL, HPOUTR) Output Power Signal to Noise ratio Total Harmonic Distortion + Noise PO SNR THD+N RL = 16; THD+N = 1% 33 A-weighted 104 dB RL = 32; PO = 20mW -88 dB RL = 32; PO = 5mW -84 RL = 16; PO = 20mW -80 RL = 16; PO = 5mW -79 DC Offset 0.5 Channel separation Mute attenuation Power supply rejection ENA = 0 PSRR Maximum load capacitance 100mV pk-pk @ 217Hz on VDD 1 mV TBD dB 95 dB TBD HPOUTL or HPOUTR dB 2 nF 0.2 x VDD V Digital Input (ENA) Input high level 0.8 x VDD V Input low level Other Parameters Quiescent current IVDD ENA = 1, Inputs grounded 1 Shutdown current IVDD ENA = 0 1 A 12 ms Start-up time w mA PTD, May 2010, Rev 2.0 6 Preliminary Technical Data WM9010 TERMINOLOGY 1. Signal-to-Noise Ratio (dB) - SNR is the difference in level between a full scale output signal and the device output noise with no signal applied, measured over a bandwidth of 20Hz to 20kHz. This ratio is also called idle channel noise. (No Auto-zero or Mute function is employed). 2. Total Harmonic Distortion (dB) - THD is the difference in level between a 1kHz reference sine wave output signal and the first seven harmonics of the output signal. The amplitude of the fundamental frequency of the output signal is compared to the RMS value of the next seven harmonics and expressed as a ratio. 3. Total Harmonic Distortion plus Noise (dB) - THD+N is the difference in level between a 1kHz reference sine wave output signal and all noise and distortion products in the audio band. The amplitude of the fundamental reference frequency of the output signal is compared to the RMS value of all other noise and distortion products and expressed as a ratio. 4. Channel Separation (L/R) (dB) - is a measure of the coupling between left and right channels. A full scale signal is applied to the left channel only, and the right channel amplitude is measured. Next, a full scale signal is applied to the right channel only, and the left channel amplitude is measured. The worst case channel separation is quoted; this is the difference in level between the full-scale output and the cross-channel output signal level, expressed as a ratio. 5. Power Supply Rejection Ratio (dB) - PSRR is a measure of ripple attenuation between a power supply rail and a signal output path. With the signal path idle, a small sine wave ripple is applied to power supply rail. The amplitude of the supply ripple is compared to the amplitude of the output signal generated and is expressed as a ratio. 6. Mute attenuation - This is a measure of the difference in level between the full scale output signal and the output with mute applied (ie. ENA = logic 0). 7. All performance measurements are carried out with 20kHz AES17 low pass filter for distortion measurements, and an A-weighted filter for noise measurement. Failure to use such a filter will result in higher THD and lower SNR and Dynamic Range readings than are found in the Electrical Characteristics. The low pass filter removes out-of-band noise; although it is not audible, it may affect dynamic specification values. w PTD, May 2010, Rev 2.0 7 WM9010 Preliminary Technical Data DEVICE DESCRIPTION INTRODUCTION The WM9010 is a low power stereo headphone driver designed for mobile handset and portable media player (PMP) applications. It is packaged in a 12-pin CSP. The device comprises two analogue input pins, each accepting line signals up to 1Vrms. The signal path gain is fixed at 0dB. The headphone output drivers deliver up to 28mW into a 32 load. The WM9010 incorporates Class G technology to achieve high efficiency and low quiescent current. An integrated charge pump circuit is used to generate the split (positive and negative) power rails from a single VDD supply. The ground-referenced headphone driver design reduces the device power consumption and also eliminates external DC-blocking capacitors on the audio output path. The WM9010 is enabled when a logic high level is detected on ENA. Note that the ENA pin can support digital logic levels up to 2.7V. Wolfson's Silent SwitchTM technology is incorporated in order to minimise `pop' noise whenever the WM9010 is enabled or disabled. A power on reset circuit ensures correct start-up and shut-down when VDD is switched on or off. The WM9010 is held in reset when the ENA pin is held low, offering a low-power standby state. Short circuit and thermal protection is also provided. HEADPHONE DRIVER The WM9010 has two analogue input pins, INL and INR. The maximum analogue input signal level varies with VDD, but is typically 0dBV (1Vrms) when VDD = 1.8V. This is suitable for single-ended connection to line level input signals. The headphone output drivers are capable of driving up to 28mW into a 32 load such as a stereo headset or headphones. The outputs are ground-referenced, eliminating any requirement for AC coupling capacitors. This is achieved by having separate positive and negative supply rails powered by an on-chip charge pump. A pop-suppression circuit ensures that DC offsets are minimised, suppressing `pop' noise and reducing power consumption. To obtain optimal DC offsets, the device should be powered on with no signal on the input pins. The headphone output incorporates a common mode, or ground loop, feedback path which provides rejection of system-related ground noise. The return path is via HPOUTFB. This pin should be connected to the headphone as illustrated in Figure 2. It is recommended to connect a zobel network to the headphone output pins HPOUTL and HPOUTR for best audio performance in all applications. The components of the zobel network have the effect of dampening high frequency oscillations or instabilities that can arise outside the audio band under certain conditions. Possible sources of these instabilities include the inductive load of a headphone coil or an active load in the form of an external line amplifier. The capacitance of lengthy cables or PCB tracks can also lead to amplifier instability. The zobel network should comprise of a 20 resistor and 100nF capacitor in series with each other, as illustrated in Figure 2. w PTD, May 2010, Rev 2.0 8 WM9010 Preliminary Technical Data Figure 2 External Connections for HPOUTL and HPOUTR CHARGE PUMP The WM9010 incorporates a charge pump circuit, which generates the supply rails for the headphone output drivers. The charge pump is powered from VDD, and generates split rails CPVOUTP and CPVOUTN. The circuit is adaptive according to the audio signal conditions, supporting the Class G operation and ensuring optimum circuit configuration at all times. The switching clock for the charge pump is generated internally. The external connections for the charge pump are illustrated in Figure 3. A fly-back capacitor is connected between the CPCA and CPCB pins. De-coupling capacitors are required on CPVOUTP and CPVOUTN. An input decoupling capacitor may also be required at VDD, depending upon the system configuration. Figure 3 External Connections for Charge Pump w PTD, May 2010, Rev 2.0 9 WM9010 Preliminary Technical Data APPLICATIONS INFORMATION RECOMMENDED EXTERNAL COMPONENTS Figure 4 provides a summary of recommended external components for WM9010. Note that the actual requirements may differ according to the specific target application. Figure 4 WM9010 Recommended External Components Diagram PCB LAYOUT CONSIDERATIONS Poor PCB layout will degrade the performance and be a contributory factor in EMI, ground bounce and resistive voltage losses. All external components should be placed as close to the WM9010 device as possible, with current loop areas kept as small as possible. w PTD, May 2010, Rev 2.0 10 WM9010 Preliminary Technical Data PACKAGE DIMENSIONS B: 12 BALL W-CSP PACKAGE 1.840 X 1.340 X 0.7mm BODY, 0.50 mm BALL PITCH DM078.A 4 A D DETAIL 1 A2 4 2 3 1 2 A1 CORNER A E1 B E 4 e 3 C 4X e 0.05 DETAIL 2 D1 BOTTOM VIEW TOP VIEW f1 SOLDER BALL f2 bbb Z h 1 Z A1 DETAIL 1 DETAIL 2 Symbols A A1 A2 D D1 E E1 e f1 f2 MIN 0.675 0.187 0.488 1.820 1.320 Dimensions (mm) NOM MAX 0.7 0.725 0.2 0.213 0.512 0.500 1.860 1.840 1.500 BSC 1.360 1.340 1.000 BSC 0.500 BSC NOTE 3 0.160 0.160 h 0.267 NOTES: 1. PRIMARY DATUM -Z- AND SEATING PLANE ARE DEFINED BY THE SPHERICAL CROWNS OF THE SOLDER BALLS. 2. A1 CORNER IS IDENTIFIED BY INK/LASER MARK ON TOP PACKAGE. 3. `e' REPRESENTS THE BASIC SOLDER BALL GRID PITCH. 4. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE. 5. FOLLOWS JEDEC DESIGN GUIDE MO-211-C. w PTD, May 2010, Rev 2.0 11 WM9010 Preliminary Technical Data 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 utilized 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 minimize 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 26 Westfield Road Edinburgh EH11 2QB United Kingdom Tel :: +44 (0)131 272 7000 Fax :: +44 (0)131 272 7001 Email :: sales@wolfsonmicro.com w PTD, May 2010, Rev 2.0 12