w WM8727 24-bit 192kHz Stereo DAC DESCRIPTION FEATURES The WM8727 is a high performance stereo DAC designed for audio applications such as DVD, home theatre systems, and digital TV. The WM8727 supports data input word lengths from 16 to 24-bits and sampling rates up to 192kHz. The WM8727 consists of a serial interface port, digital interpolation filters, multi-bit sigma delta modulators and stereo DAC in a very small 8-pin SOIC package. • • Stereo DAC Audio Performance • 98dB SNR (‘A’ weighted @ 48kHz) DAC -84dB THD DAC Sampling Frequency: 8kHz – 192kHz The WM8727 supports a 16-24-bit I2S digital audio interface. The WM8727 is an ideal device to interface to AC-3, DTS, and MPEG audio decoders for surround sound applications, or for use in DVD players, including supporting the implementation of 2 channels at 192kHz for high-end DVD-Audio applications. • • Audio Data Interface Format 16-24-Bit I2S 2.7V – 5.5V Supply Operation • • 8-pin SOIC Package Exceeds Dolby Class A Performance Requirements APPLICATIONS • • DVD Players Digital TV • Digital Set Top Box BLOCK DIAGRAM MUTE BCKIN LRCIN SERIAL INTERFACE SIGMA DELTA MODULATOR RIGHT DAC LOW PASS FILTER VOUTR SIGMA DELTA MODULATOR LEFT DAC LOW PASS FILTER VOUTL DIGITAL FILTERS DIN MUTE W WM8727 MCLK WOLFSON MICROELECTRONICS plc www.wolfsonmicro.com VDD GND Production Data, April 2004, Rev 4.1 Copyright 2004 Wolfson Microelectronics plc WM8727 Production Data TABLE OF CONTENTS DESCRIPTION ............................................................................................................1 FEATURES..................................................................................................................1 APPLICATIONS ..........................................................................................................1 BLOCK DIAGRAM ......................................................................................................1 TABLE OF CONTENTS ..............................................................................................2 PIN CONFIGURATION................................................................................................3 ORDERING INFORMATION .......................................................................................3 PIN DESCRIPTION .....................................................................................................3 ABSOLUTE MAXIMUM RATINGS..............................................................................4 DC ELECTRICAL CHARACTERISTICS .....................................................................4 ELECTRICAL CHARACTERISTICS ...........................................................................5 TERMINOLOGY ................................................................................................................. 6 MASTER CLOCK TIMING .................................................................................................. 6 DIGITAL AUDIO INTERFACE ............................................................................................ 6 DEVICE DESCRIPTION..............................................................................................8 GENERAL INTRODUCTION .............................................................................................. 8 DAC CIRCUIT DESCRIPTION ........................................................................................... 8 CLOCKING SCHEMES ...................................................................................................... 9 DIGITAL AUDIO INTERFACE ............................................................................................ 9 AUDIO DATA SAMPLING RATES.....................................................................................10 DIGITAL FILTER CHARACTERISTICS ....................................................................11 DAC FILTER RESPONSES...............................................................................................11 TYPICAL PERFORMANCE.......................................................................................12 APPLICATIONS INFORMATION ..............................................................................13 RECOMMENDED EXTERNAL COMPONENTS ................................................................13 RECOMMENDED EXTERNAL COMPONENTS VALUES .................................................13 RECOMMENDED ANALOGUE LOW PASS FILTER (OPTIONAL) ...................................14 PCB LAYOUT RECOMMENDATIONS ..............................................................................14 PACKAGE DRAWING...............................................................................................15 IMPORTANT NOTICE ...............................................................................................16 ADDRESS: ........................................................................................................................16 w PD Rev 4.1 April 2004 2 WM8727 Production Data PIN CONFIGURATION DIN 1 8 VOUTL BCKIN 2 7 VDD LRCIN 3 6 GND MCLK 4 5 VOUTR WM8727 ORDERING INFORMATION DEVICE TEMPERATURE RANGE PACKAGE MOISTURE SENSITIVITY LEVEL PEAK SOLDERING TEMPERATURE WM8727ED -25 to +85oC 8-pin SOIC MSL1 240oC WM8727ED/R -25 to +85oC MSL1 240 C WM8727GED/V -25 to +85 C MSL2 260oC WM8727GED/RV -25 to +85oC 8-pin SOIC (tape and reel) 8-pin SOIC (lead free) 8-pin SOIC (lead free, tape and reel) MSL2 260oC o o Note: Reel Quantity = 3,000 PIN DESCRIPTION PIN NAME TYPE Digital input DESCRIPTION 1 DIN Serial audio data input 2 BCKIN Digital input Bit clock input 3 LRCIN Digital input Sample rate clock input 4 MCLK Digital input System clock input 5 VOUTR Analogue output Right channel DAC output 6 GND Supply Analogue ground supply 7 VDD Supply Positive supply 8 VOUTL Analogue output Left channel DAC output Note: Digital input pins have Schmitt trigger input buffers. w PD Rev 4.1 April 2004 3 WM8727 Production 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 <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. MIN MAX -0.3V +7V GND -0.3V VDD +0.3V CONDITION Supply voltage Voltage range digital inputs Master Clock Frequency 50MHz Operating temperature range, TA -25°C Storage temperature prior to soldering +85°C 30°C max / 85% RH max Storage temperature after soldering -65°C +150°C DC ELECTRICAL CHARACTERISTICS PARAMETER SYMBOL Supply range VDD Ground GND TEST CONDITIONS MIN TYP 2.7 MAX UNIT 5.5 V 0 V 27 mA Supply current VDD = 5V Supply current VDD = 3.3V 23 mA Power down current (note 3) VDD = 3.3V 0.5 mA w PD Rev 4.1 April 2004 4 WM8727 Production Data ELECTRICAL CHARACTERISTICS Test Conditions VDD = 5V, GND = 0V, TA = +25oC, fs = 48kHz, MCLK = 256fs unless otherwise stated. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT 0.8 V 0.10 x VDD V Digital Logic Levels (TTL Levels) Input LOW level VIL Input HIGH level VIH Output LOW VOL IOL = 2mA Output HIGH VOH IOH = 2mA 2 V 0.9 x VDD V DAC Output (Load = 10kΩ Ω 50pF) 0dBFs Full scale output voltage SNR (Note 1,2) SNR (Note 1,2) SNR (Note 1,2) SNR (Note 1,2) SNR (Note 1,2) SNR (Note 1,2) THD Dynamic range (Note 2) At DAC outputs A-weighted, @ fs = 48kHz A-weighted @ fs = 96kHz A-weighted @ fs = 192kHz A-weighted, @ fs = 48kHz VDD = 3.3V A-weighted @ fs = 96kHz VDD = 3.3V Non ‘A’ weighted @ fs = 48kHz 1kHz, 0dBFs 1.2 x VDD/5 98 VRMS dB 95 dB 92 dB 95 dB 95 dB 92 dB -84 dB 1kHz, THD+N @ -60dBFs 98 dB Load = 10kΩ, 0dBFS Load = 10kΩ, 0dBFS, (VDD = 3.3V) 1.2 0.79 VRMS VRMS ±1 %FSR 1 kΩ 1 kΩ Analogue Output Levels Output level Gain mismatch channel-to-channel Minimum resistance load Maximum capacitance load Output d.c. level To midrail or a.c. coupled To midrail or a.c. coupled (VDD = 3.3V) 5V or 3.3V 100 pF VDD/2 V 1.8 V Power On Reset (POR) POR threshold Notes: 1. Ratio of output level with 1kHz full scale input, to the output level with all zeros into the digital input, measured ‘A’ weighted over a 20Hz to 20kHz bandwidth. 2. All performance measurements done with 20kHz low pass filter, and where noted an A-weight filter. Failure to use such a filter will result in higher THD+N 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. 3. Power down occurs 1.5µs after MCLK stops. w PD Rev 4.1 April 2004 5 WM8727 Production Data TERMINOLOGY 1. Signal-to-noise ratio (dB) - SNR is a measure of the difference in level between the full scale output and the output with no signal applied. (No Auto-zero or Automute function is employed in achieving these results). 2. Dynamic range (dB) - DNR is a measure of the difference between the highest and lowest portions of a signal. Normally a THD+N measurement at 60dB below full scale. The measured signal is then corrected by adding the 60dB to it. (e.g. THD+N @ -60dB= -32dB, DR= 92dB). 3. THD+N (dB) - THD+N is a ratio, of the rms values, of (Noise + Distortion)/Signal. 4. Stop band attenuation (dB) - Is the degree to which the frequency spectrum is attenuated (outside audio band). 5. Channel Separation (dB) - Also known as Cross-Talk. This is a measure of the amount one channel is isolated from the other. Normally measured by sending a full scale signal down one channel and measuring the other. MASTER CLOCK TIMING tMCLKL MCLK tMCLKH tMCLKY Figure 1 Master Clock Timing Requirements Test Conditions VDD = 5V, GND = 0V, TA = +25oC, fs = 48kHz, MCLK = 256fs unless otherwise stated. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT System Clock Timing Information MCLK Master clock pulse width high tMCLKH 8 ns MCLK Master clock pulse width low tMCLKL 8 ns MCLK Master clock cycle time tMCLKY 20 MCLK Duty cycle Time from MCLK stopping to power down. ns 40:60 60:40 1.5 12 µs DIGITAL AUDIO INTERFACE tBCH tBCL BCKIN tBCY LRCIN tDS tLRH tLRSU DIN tDH Figure 2 Digital Audio Data Timing w PD Rev 4.1 April 2004 6 WM8727 Production Data Test Conditions VDD = 5V, GND = 0V, TA = +25oC, fs = 48kHz, MCLK = 256fs unless otherwise stated. PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Audio Data Input Timing Information BCKIN cycle time tBCY 40 ns BCKIN pulse width high tBCH 16 ns BCKIN pulse width low tBCL 16 ns LRCIN set-up time to BCKIN rising edge tLRSU 8 ns LRCIN hold time from BCKIN rising edge tLRH 8 ns DIN set-up time to BCKIN rising edge tDS 8 ns DIN hold time from BCKIN rising edge tDH 8 ns w PD Rev 4.1 April 2004 7 WM8727 Production Data DEVICE DESCRIPTION GENERAL INTRODUCTION The WM8727 is a high performance DAC designed for digital consumer audio applications. The range of features make it ideally suited for use in DVD players, AV receivers and other consumer audio equipment. The WM8727 is a complete 2-channel stereo audio digital-to-analogue converter, including digital interpolation filter, multi-bit sigma delta with dither, and switched capacitor multi-bit stereo DAC and output smoothing filters. It is fully compatible and an ideal partner for a range of industry standard microprocessors, controllers and DSPs. A novel multi bit sigma-delta DAC design is used, utilising a 128x oversampling rate, to optimise signal to noise performance and offer increased clock jitter tolerance. (In ‘high-rate’ operation, the oversampling ratio is 64x for system clocks of 128fs or 192fs) Operation using master clocks of 256fs, 384fs, 512fs or 768fs is provided, selection between clock rates being automatically controlled. Sample rates (fs) from less than 8ks/s to 96ks/s are allowed, provided the appropriate system clock is input. Support is also provided for up to 192ks/s using a master clock of 128fs or 192fs. The audio data interface supports 16-24-bit I2S (Philips left justified, one bit delayed) interface format. A DSP interface is also supported, enhancing the interface options for the user. A single 2.7-5.5V supply may be used, the output amplitude scaling with absolute supply level. Low supply voltage operation and low current consumption combined with the low pin count small package make the WM8727 attractive for many consumer applications. The device is packaged in a small 8-pin SOIC. DAC CIRCUIT DESCRIPTION The WM8727 DAC is designed to allow playback of 24-bit PCM audio or similar data with high resolution and low noise and distortion. Sample rates up to 192ks/s may be used, with much lower sample rates acceptable provided that the ratio of sample rate (LRCIN) to system clock (MCLK) is maintained at one of the required rates. The two DACs on the WM8727 are implemented using sigma-delta oversampled conversion techniques. These require that the PCM samples are digitally filtered and interpolated to generate a set of samples at a much higher rate than the up to 192ks/s input rate. This sample stream is then digitally modulated to generate a digital pulse stream that is then converted to analogue signals in a switched capacitor DAC. The advantage of this technique is that the DAC is linearised using noise shaping techniques, allowing the 24-bit resolution to be met using noncritical analogue components. A further advantage is that the high sample rate at the DAC output means that smoothing filters on the output of the DAC need only have fairly crude characteristics in order to remove the characteristic steps, or images, on the output of the DAC. To ensure that generation of tones characteristic to sigma-delta convertors is not a problem, dithering is used in the digital modulator and a higher order modulator is used. The multi-bit switched capacitor technique used in the DAC reduces sensitivity to clock jitter, and dramatically reduces out of band noise compared to switched current or single bit techniques used in other implementations. The outputs of the 2 DACs are buffered out of the device by buffer amplifiers. These amplifiers will source load currents of several mA and sink current up to 1.5mA allowing significant loads to be driven. The output source is active and the sink is Class A, i.e. fixed value, so greater loads might be driven if an external ‘pull-down’ resistor is connected at the output. Typically an external low pass filter circuit will be used to remove residual out of band noise characteristic of delta sigma converters. However, the advanced multi-bit DAC used in WM8727 produces far less out of band noise than single bit traditional sigma delta DACs, and so in many applications this filter may be removed, or replaced with a simple RC pole. w PD Rev 4.1 April 2004 8 WM8727 Production Data CLOCKING SCHEMES In a typical digital audio system there is only one central clock source producing a reference clock to which all audio data processing is synchronised. This clock is often referred to as the audio system’s Master Clock. The external master clock can be applied directly through the MCLK input pin with no configuration necessary for sample rate selection. Note that on the WM8727, MCLK is used to derive clocks for the DAC path. The DAC path consists of DAC sampling clock, DAC digital filter clock and DAC digital audio interface timing. In a system where there are a number of possible sources for the reference clock it is recommended that the clock source with the lowest jitter be used to optimise the performance of the DAC. The device can be powered down by stopping MCLK. In this state the power consumption is substantially reduced. DIGITAL AUDIO INTERFACE Audio data is applied to the internal DAC filters via the Digital Audio Interface. The WM8727 supports the popular I2S audio interface format. The WM8727 supports word lengths of 16-24 bits (MSB first). The word length may be any value up to 24-bits. (If a word length shorter than 24-bits is used, the unused bits will be padded with zeros). ‘Packed’ mode (i.e. only 32 or 48 clocks per LRCIN period) operation is also supported. If a ‘packed’ format of 16-bit word length is applied (16 BCKINS per LRCIN half period), the device auto-detects this mode and switches to 16-bit data length. The digital audio interface receives data on the DIN input. Audio Data is time multiplexed with LRCIN indicating whether the left or right channel is present. LRCIN is also used as a timing reference to indicate the beginning or end of the data words. The minimum number of BCKINs per LRCIN period is 2 times the selected word length. LRCIN must be high for a minimum of word length BCKINs and low for a minimum of word length BCKINs. Any mark to space ratio on LRCIN is acceptable provided the above requirements are met. In the I2S mode, the MSB is sampled on the second rising edge of BCKIN following a LRCIN transition. LRCIN is low during the left samples and high during the right samples. 1/fs LEFT CHANNEL RIGHT CHANNEL LRCIN BCKIN 1 BCKIN 1 BCKIN DIN 1 2 3 MSB n-2 n-1 n LSB 1 MSB 2 3 n-2 n-1 n LSB Figure 3 I2S Mode Timing Diagram w PD Rev 4.1 April 2004 9 WM8727 Production Data AUDIO DATA SAMPLING RATES The master clock for WM8727 supports audio sampling rates from 128fs to 768fs, where fs is the audio sampling frequency (LRCIN) typically 32kHz, 44.1kHz, 48kHz, 96kHz or 192kHz. The master clock is used to operate the digital filters and the noise shaping circuits. The WM8727 has a master clock detection circuit that automatically determines the relation between the master clock frequency and the sampling rate (to within +/- 8 master clocks). If there is a greater than 8 clocks error, the interface shuts down the DAC and mutes the output. The master clock should be synchronised with LRCIN, although the WM8727 is tolerant of phase differences or jitter on this clock. SAMPLING RATE (LRCIN) 32kHz 44.1kHz 48kHz 96kHz 192kHz MASTER CLOCK FREQUENCY (MHZ) (MCLK) 128fs 192fs 256fs 384fs 512fs 768fs 4.096 5.6448 6.144 12.288 24.576 6.144 8.467 9.216 18.432 36.864 8.192 11.2896 12.288 24.576 Unavailable 12.288 16.9344 18.432 36.864 Unavailable 16.384 22.5792 24.576 Unavailable Unavailable 24.576 33.8688 36.864 Unavailable Unavailable Table 1 Master Clock Frequencies Versus Sampling Rate w PD Rev 4.1 April 2004 10 WM8727 Production Data DIGITAL FILTER CHARACTERISTICS PARAMETER SYMBOL TEST CONDITIONS Passband Edge -3dB Passband Ripple f < 0.444fs Stopband Attenuation f > 0.555fs MIN TYP MAX UNIT ±0.05 dB 0.487fs -60 dB Table 2 Digital Filter Characteristics DAC FILTER RESPONSES 0.2 0 0.15 -20 -40 Response (dB) Response (dB) 0.1 -60 0.05 0 -0.05 -80 -0.1 -100 -0.15 -120 -0.2 0 0.5 1 1.5 Frequency (Fs) 2 2.5 3 Figure 4 DAC Digital Filter Frequency Response 0 0.05 0.1 0.15 0.2 0.25 0.3 Frequency (Fs) 0.35 0.4 0.45 0.5 Figure 5 DAC Digital Filter Ripple -44.1, 48 and 96kHz -44.1, 48 and 96kHz 0.2 0 0 -0.2 Response (dB) Response (dB) -20 -40 -0.4 -0.6 -60 -0.8 -80 -1 0 0.2 0.4 0.6 Frequency (Fs) 0.8 1 Figure 6 DAC Digital Filter Frequency Response – 192kHz w 0 0.05 0.1 0.15 0.2 0.25 0.3 Frequency (Fs) 0.35 0.4 0.45 0.5 Figure 7 DAC Digital Filter Ripple –192kHz PD Rev 4.1 April 2004 11 WM8727 Production Data TYPICAL PERFORMANCE -65 -70 -75 -80 -85 d B r -90 -95 B -100 -105 -110 -115 -120 -160 -150 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 +0 dBFS Figure 8 WM8727 Functionality THD+N VDD = 5V -70 -72.5 -75 -77.5 -80 -82.5 -85 -87.5 -90 d B r B -92.5 -95 -97.5 -100 -102.5 -105 -107.5 -110 -112.5 -115 -117.5 -120 -160 -150 -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 +0 dBFS Figure 9 WM8727 Functionality THD+N VDD = 3V w PD Rev 4.1 April 2004 12 WM8727 Production Data APPLICATIONS INFORMATION RECOMMENDED EXTERNAL COMPONENTS VDD 7 + C1 VDD C2 6 GND AGND 5 WM8727 3 4 Audio Serial Data I/F 2 1 8 C4 AC-Coupled VOUTR/L to External LPF + VOUTL C3 + VOUTR LRCIN MCLK BCKIN DIN Notes: 1. C2 should be positioned as close to the WM8727 as possible. 2. Capacitor types should be carefully chosen. Capacitors with very low ESR are recommended for optimum performance. 3. C3 and C4 not required if using the recommended low pass filter in Figure 9. Figure 10 External Component Diagram RECOMMENDED EXTERNAL COMPONENTS VALUES COMPONENT REFERENCE SUGGESTED VALUE DESCRIPTION C1 10µF De-coupling for VDD C2 0.1µF De-coupling for VDD C3 and C4 10µF Output AC coupling caps to remove midrail DC level from outputs Table 3 External Components Description w PD Rev 4.1 April 2004 13 WM8727 Production Data RECOMMENDED ANALOGUE LOW PASS FILTER (OPTIONAL) 4.7kΩ 4.7kΩ +VS _ 51Ω 10uF + 1.8kΩ 7.5KΩ + 1.0nF 680pF -VS 47kΩ Figure 11 Recommended Low Pass Filter (Optional) An external low pass filter is recommended (see Figure 20) if the device is driving a wideband amplifier. In some applications, a passive RC filter may be adequate. PCB LAYOUT RECOMMENDATIONS Care should be taken in the layout of the PCB that the WM8727 is to be mounted to. The following notes will help in this respect: 1. The VDD supply to the device should be as noise free as possible. This can be accomplished to a large degree with a 10uF bulk capacitor placed locally to the device and a 0.1uF high frequency decoupling capacitor placed as close to the VDD pin as possible. It is best to place the 0.1uF capacitor directly between the VDD and GND pins of the device on the same layer to minimize track inductance and thus improve device decoupling effectiveness. 2. Separate analogue and digital track routing from each other. The device is split into analogue (pins 5 – 8) and digital (pins 1 – 4) sections that allow the routing of these signals to be easily separated. By physically separating analogue and digital signals, crosstalk from the PCB can be minimized. 3. Use an unbroken solid GND plane. To achieve best performance from the device, it is advisable to have either a GND plane layer on a multilayer PCB or to dedicate one side of a 2 layer PCB to be a GND plane. For double sided implementations it is best to route as many signals as possible on the device mounted side of the board, with the opposite side acting as a GND plane. The use of a GND plane greatly reduces any electrical emissions from the PCB and minimizes crosstalk between signals. An evaluation board is available for the WM8727 that demonstrates the above techniques and the excellent performance achievable from the device. This can be ordered or the User manual downloaded from the Wolfson web site at www.wolfsonmicro.com w PD Rev 4.1 April 2004 14 WM8727 Production Data PACKAGE DRAWING D: 8 PIN SOIC 3.9mm Wide Body DM009.B B e 8 5 E 1 H L 4 D h x 45o A A1 -C- 0.10 (0.004) Symbols A A1 B C D e E h H L α Dimensions (mm) MIN MAX 1.35 1.75 0.10 0.25 0.33 0.51 0.19 0.25 4.80 5.00 1.27 BSC 3.80 4.00 0.25 0.50 5.80 6.20 0.40 1.27 o o 8 0 REF: α SEATING PLANE C Dimensions (Inches) MIN MAX 0.0532 0.0688 0.0040 0.0098 0.0130 0.0200 0.0075 0.0098 0.1890 0.1968 0.050 BSC 0.1497 0.1574 0.0099 0.0196 0.2284 0.2440 0.0160 0.0500 o o 0 8 JEDEC.95, MS-012 NOTES: A. ALL LINEAR DIMENSIONS ARE IN MILLIMETERS (INCHES). B. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE. C. BODY DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSION, NOT TO EXCEED 0.25MM (0.010IN). D. MEETS JEDEC.95 MS-012, VARIATION = AA. REFER TO THIS SPECIFICATION FOR FURTHER DETAILS. w PD Rev 4.1 April 2004 15 WM8727 Production Data IMPORTANT NOTICE Wolfson Microelectronics plc (WM) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current. All products are sold subject to the WM terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. WM warrants performance of its products to the specifications applicable at the time of sale in accordance with WM’s standard warranty. Testing and other quality control techniques are utilised to the extent WM deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. In order to minimise risks associated with customer applications, adequate design and operating safeguards must be used by the customer to minimise inherent or procedural hazards. Wolfson products are not authorised for use as critical components in life support devices or systems without the express written approval of an officer of the company. Life support devices or systems are devices or systems that are intended for surgical implant into the body, or support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided, can be reasonably expected to result in a significant injury to the user. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. WM assumes no liability for applications assistance or customer product design. WM does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of WM covering or relating to any combination, machine, or process in which such products or services might be or are used. WM’s publication of information regarding any third party’s products or services does not constitute WM’s approval, license, warranty or endorsement thereof. Reproduction of information from the WM web site or datasheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations and notices. Representation or reproduction of this information with alteration voids all warranties provided for an associated WM product or service, is an unfair and deceptive business practice, and WM is not responsible nor liable for any such use. Resale of WM’s products or services with statements different from or beyond the parameters stated by WM for that product or service voids all express and any implied warranties for the associated WM product or service, is an unfair and deceptive business practice, and WM is not responsible nor liable for any such use. ADDRESS: Wolfson Microelectronics plc Westfield House 26 Westfield Road Edinburgh EH11 2QB United Kingdom Tel :: +44 (0)131 272 7000 Fax :: +44 (0)131 272 7001 Email :: [email protected] w PD Rev 4.1 April 2004 16