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Wolfson WM8978 Скачать руководство пользователя страница 43

Production Data

WM8978

w

PD, Rev 4.5, October 2011

43

ALC HOLD TIME (NORMAL MODE ONLY)

In Normal mode, the ALC has an adjustable hold time which sets a time delay before the ALC begins
its decay phase (gain increasing). The hold time is set by the ALCHLD register.

REGISTER

ADDRESS

BIT LABEL DEFAULT

DESCRIPTION

R33
ALC Control
2

7:4

ALCHLD

0000

ALC hold time before gain is increased.

Table 23 ALC Hold Time

If the hold time is exceeded this indicates that the signal has reached a new average level and the
ALC will increase the gain to adjust for that new average level. If the signal goes above the threshold
during the hold period, the hold phase is abandoned and the ALC returns to normal operation.

Figure 20 ALCLVL

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Содержание WM8978

Страница 1: ...MHz The WM8978 operates at analogue supply voltages from 2 5V to 3 3V although the digital core can operate at voltages down to 1 71V to save power The speaker outputs and OUT3 4 line outputs can run...

Страница 2: ...DE 17 CONTROL INTERFACE TIMING 2 WIRE MODE 18 INTERNAL POWER ON RESET CIRCUIT 19 DEVICE DESCRIPTION 21 INTRODUCTION 21 INPUT SIGNAL PATH 23 ANALOGUE TO DIGITAL CONVERTER ADC 30 INPUT LIMITER AUTOMATIC...

Страница 3: ...ction Data WM8978 w PD Rev 4 5 October 2011 3 5 BAND EQUALISER 111 APPLICATION INFORMATION 115 RECOMMENDED EXTERNAL COMPONENTS 115 PACKAGE DIAGRAM 116 IMPORTANT NOTICE 117 ADDRESS 117 REVISION HISTORY...

Страница 4: ...FORMATION ORDER CODE TEMPERATURE RANGE PACKAGE MOISTURE SENSITIVITY LEVEL PEAK SOLDERING TEMPERATURE WM8978CGEFL V 40 C to 100 C 32 lead QFN 5 x 5 mm Pb free MSL3 260 o C WM8978CGEFL RV 40 C to 100 C...

Страница 5: ...SDIN Digital Input Output 3 Wire Control Interface Data Input 2 Wire Control Interface Data Input 18 MODE Digital Input Control Interface Selection 19 AUXL Analogue input Left Auxillary input 20 AUXR...

Страница 6: ...e 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 Informat...

Страница 7: ...grammable Gain Step Size Guaranteed monotonic 0 75 dB Mute Attenuation 120 dB Selectable Input Gain Boost 0 20dB Gain Boost on PGA input Boost disabled 0 dB Boost enabled 20 dB Maximum Gain from AUXL...

Страница 8: ...al to Noise Ratio Note 6 SNR A weighted 0dB gain 85 95 dB Total Harmonic Distortion Note 7 THD 3dBFS input 84 74 dB Channel Separation Note 9 1kHz input signal 110 dB Digital to Analogue Converter DAC...

Страница 9: ...RL 8 90 dB Power Supply Rejection Ratio 50Hz 22kHz PSRR RL 8 BTL 80 dB RL 8 BTL SPKVDD 5V boost 69 dB OUT3 OUT4 Outputs with 10k 50pF load Full scale output voltage 0dB gain Note 10 OUT3BOOST 0 OUT4BO...

Страница 10: ...times scale proportionally with MCLK 6 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 Automut...

Страница 11: ...Production Data WM8978 w PD Rev 4 5 October 2011 11 SPEAKER OUTPUT THD VERSUS POWER...

Страница 12: ...rrent will fall to nearer 15uA when thermal shutdown sensor is disabled Table 1 Power Consumption ESTIMATING SUPPLY CURRENT When either the DAC or ADC is enabled approximately 7mA will be drawn from D...

Страница 13: ...settings ROUT1EN 0 4 LOUT1EN 0 4 BOOSTENR 0 2 BOOSTENL 0 2 INPPGAENR 0 2 INPPGAENL 0 2 ADCENR 2 6 x64 ADCOSR 0 4 9 x128 ADCOSR 1 ADCENL 2 6 x64 ADCOSR 0 4 9 x128 ADCOSR 1 OUT4EN 0 2 OUT3EN 0 2 LOUT2EN...

Страница 14: ...WM8978 Production Data w PD Rev 4 5 October 2011 14 AUDIO PATHS OVERVIEW...

Страница 15: ...ND 0V TA 25 o C PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT System Clock Timing Information MCLK cycle time TMCLKY MCLK SYSCLK 256fs 81 38 ns MCLK input to PLL Note 1 20 ns MCLK duty cycle TMCLKDS 60...

Страница 16: ...E TIMING SLAVE MODE Figure 3 Digital Audio Data Timing Slave Mode Test Conditions DCVDD 1 8V DBVDD AVDD SPKVDD 3 3V DGND AGND SPKGND 0V TA 25 o C Slave Mode fs 48kHz MCLK 256fs 24 bit data unless othe...

Страница 17: ...ata unless otherwise stated PARAMETER SYMBOL MIN TYP MAX UNIT Program Register Input Information SCLK rising edge to CSB rising edge tSCS 80 ns SCLK pulse cycle time tSCY 200 ns SCLK pulse width low t...

Страница 18: ...8kHz MCLK 256fs 24 bit data unless otherwise stated PARAMETER SYMBOL MIN TYP MAX UNIT Program Register Input Information SCLK Frequency 0 526 kHz SCLK Low Pulse Width t1 1 3 us SCLK High Pulse Width t...

Страница 19: ...uence where AVDD is Powered before DVDD Figure 7 shows a typical power up sequence where AVDD comes up first When AVDD goes above the minimum threshold Vpora there is enough voltage for the circuit to...

Страница 20: ...PORB is asserted low whenever DVDD drops below the minimum threshold Vpord_off SYMBOL MIN TYP MAX UNIT Vpora 0 4 0 6 0 8 V Vpora_on 0 9 1 2 1 6 V Vpora_off 0 4 0 6 0 8 V Vpord_on 0 5 0 7 0 9 V Vpord_...

Страница 21: ...ng volume constant LINE INPUTS AUXL AUXR The inputs AUXL and AUXR can be used as a stereo line input or as an input for warning tones or beeps etc These inputs can be summed into the record paths alon...

Страница 22: ...generate alternative clocks which may then be output on the GPIO pins and used elsewhere in the system POWER CONTROL The design of the WM8978 has given much attention to power consumption without comp...

Страница 23: ...re are two auxiliary input pins which can be fed into to the input boost mix stage as well as driving into the output path A bypass path exists from the output of the boost mix stage into the output l...

Страница 24: ...P2INPPGA 1 Connect RIP pin to right channel input PGA amplifier positive terminal 0 RIP not connected to input PGA 1 right channel input PGA amplifier positive terminal connected to RIP constant input...

Страница 25: ...lume control 5 0 INPPGAVOLR 010000 Right channel input PGA volume 000000 12dB 000001 11 25db 010000 0dB 111111 35 25dB 6 INPPGAMUTER 0 Mute control for right channel input PGA 0 Input PGA not muted no...

Страница 26: ...while the signal is a non zero value an audible click can occur as shown in Figure 11 Figure 11 Click Noise During Volume Update In order to prevent this click noise a zero cross function is provided...

Страница 27: ...on If there is a long period where no zero crossing occurs a timeout circuit in the WM8978 will automatically update the volume The volume updates will occur between one and two timeout periods depend...

Страница 28: ...dual gain boost adjust as shown in Figure 14 Figure 14 Input Boost Stage The input PGA paths can have a 20dB boost PGABOOSTL R 1 a 0dB pass through PGABOOSTL R 0 or be completely isolated from the inp...

Страница 29: ...l 2 0 AUXR2BOOSTVOL 000 Controls the auxiliary amplifier to the right channel input boost stage 000 Path disabled disconnected 001 12dB gain through boost stage 010 9dB gain through boost stage 111 6d...

Страница 30: ...0 9 AVDD 1 0 65 AVDD Table 11 Microphone Bias Voltage Control The internal MICBIAS circuitry is shown in Figure 15 Note that the maximum source current capability for MICBIAS is 3mA The external bias...

Страница 31: ...ves lowest power operation and when ADCOSR 1 the oversample rate is 128x which gives best performance REGISTER ADDRESS BIT LABEL DEFAULT DESCRIPTION R14 ADC Control 0 ADCLPOL 0 ADC left channel polari...

Страница 32: ...1 010 SR 001 000 fs kHz 8 11 025 12 16 22 05 24 32 44 1 48 000 82 113 122 82 113 122 82 113 122 001 102 141 153 102 141 153 102 141 153 010 131 180 196 131 180 196 131 180 196 011 163 225 245 163 225...

Страница 33: ...lly only update when one of the NFU bits is set high R28 Notch Filter 2 6 0 NFA0 6 0 0 Notch filter a0 coefficient bits 6 0 8 NFU 0 Notch filter update The notch filter values used internally only upd...

Страница 34: ...tan 1 0 9869949627 cos 1 0 0 1 w a a 1308996939 0 cos 9869949627 0 1 1 969995945 NFA0 a0 x 213 8085 rounded to nearest whole number NFA1 a1 x 212 8069 rounded to nearest whole number These values are...

Страница 35: ...26 5dB 0 5dB steps up to 1111 1111 0dB 8 ADCVU Not latched ADC left and ADC right volume do not update until a 1 is written to ADCVU in reg 15 or 16 R16 Right channel ADC Digital Volume 7 0 ADCVOLR 7...

Страница 36: ...e ALCMODE register normal mode and peak limiter mode The ALC limiter function is enabled by setting the register bit R32 8 ALCSEL REGISTER ADDRESS BIT LABEL DEFAULT DESCRIPTION R32 20h ALC Control 1 2...

Страница 37: ...28ms 23 6ms 0001 820us 6 56ms 47 2ms 0010 1 64ms 13 1ms 94 5ms time doubles with every step 1010 or higher 420ms 3 36s 24 2s 0011 5 8ms 6dB Decay gain ramp up time ALCMODE 1 Per step Per 6dB 90 of ran...

Страница 38: ...sters When the ALC is disabled the input PGA remains at the last controlled value of the ALC An input gain update must be made by writing to the INPPGAVOLL R register bits NORMAL MODE In normal mode t...

Страница 39: ...ion ALC LIMITER MODE INITIALISATION SEQUENCE In order to properly initialise the ALC function the following sequence of register writes is required 1 Set INPPGAVOLL to the required input PGA gain R45...

Страница 40: ...pecified by the SR register NORMAL MODE ALCMODE 0 Normal Mode ALCATK tATK tATK6dB tATK90 0000 104 s 832 s 6ms 0001 208 s 1 66ms 12ms 0010 416 s 3 33ms 24ms 0011 832 s 6 66ms 48ms 0100 1 66ms 13 3ms 96...

Страница 41: ...69ms 1000 23 2ms 186ms 1 34s 1001 46 5ms 372ms 2 68s 1010 93ms 744ms 5 36s Attack Time s Table 19 ALC Limiter Mode Attack and Decay times MINIMUM AND MAXIMUM GAIN The ALCMIN and ALCMAX register bits s...

Страница 42: ...000 12 001 6 010 0 011 6 100 12 101 18 110 24 111 30 Table 22 ALC Min Gain Values Note that if the ALC gain setting strays outside the ALC operating range either by starting the ALC outside of the ra...

Страница 43: ...REGISTER ADDRESS BIT LABEL DEFAULT DESCRIPTION R33 ALC Control 2 7 4 ALCHLD 0000 ALC hold time before gain is increased Table 23 ALC Hold Time If the hold time is exceeded this indicates that the sig...

Страница 44: ...w PD Rev 4 5 October 2011 44 Figure 21 ALC Hold Time ALCHLD tHOLD s 0000 0 0001 2 67ms 0010 5 34ms 0011 10 7ms 0100 21 4ms 0101 42 7ms 0110 85 4ms 0111 171ms 1000 342ms 1001 684ms 1010 1 37s Table 24...

Страница 45: ...against a noise gate threshold NGTH The noise gate cuts in when Signal level at ADC dBFS NGTH dBFS PGA gain dB Mic Boost gain dB This is equivalent to Signal level at input pin dBFS NGTH dBFS The PGA...

Страница 46: ...WM8978 Production Data w PD Rev 4 5 October 2011 46 Figure 22 ALC Operation Above Noise Gate Threshold...

Страница 47: ...The mixers and output drivers can be separately enabled by individual control bits see Analogue Outputs Thus it is possible to utilise the analogue mixing and amplification provided by the WM8978 irr...

Страница 48: ...enabled gradually attenuates the volume of the digital signal to zero When disabled the gain will ramp back up to the digital gain setting This function is enabled by default To play back an audio si...

Страница 49: ...dB Right DAC Digital Volume Control 0000 0000 Digital Mute 0000 0001 127dB 0000 0010 126 5dB 0 5dB steps up to 1111 1111 0dB 8 DACVU Not latched DAC left and DAC right volume do not update until a 1 i...

Страница 50: ...hold the signal is amplified at a specific decay rate controlled by LIMDCY register bits until a gain of 0dB is reached Both threshold levels are controlled by the LIMLVL register bits The upper thres...

Страница 51: ...s 1010 96ms 1011 to 1111 192ms 7 4 LIMDCY 0011 Limiter Decay time per 6dB gain change for 44 1kHz sampling Note that these will scale proportionally with sample rate 0000 750us 0001 1 5ms 0010 3ms 001...

Страница 52: ...DAC path Table 30 EQ and 3D Enhancement DAC or ADC Path Select The equaliser consists of low and high frequency shelving filters Band 1 and 5 and three peak filters for the centre bands Each has adjus...

Страница 53: ...4 0 EQ4G 01100 0dB Band 4 Gain Control See Table 36 for details 6 5 EQ4C 01 Band 4 Centre Frequency 00 1 8kHz 01 2 4kHz 10 3 2kHz 11 4 1kHz 8 EQ4BW 0 Band 4 Bandwidth Control 0 narrow bandwidth 1 wid...

Страница 54: ...onfigured as a stereo line out OUT3 is left output and OUT4 is right output OUT4 can also be used to provide a mono mix of left and right channels LOUT2 ROUT2 OUT3 and OUT4 are supplied from SPKVDD an...

Страница 55: ...Production Data WM8978 w PD Rev 4 5 October 2011 55 Figure 26 Left Right Output Channel Mixers...

Страница 56: ...ot selected 1 selected 4 2 BYPLMIXVOL 000 Left bypass volume control to output channel mixer 000 15dB 001 12dB 101 0dB 110 3dB 111 6dB 5 AUXL2LMIX 0 Left Auxiliary input to left channel output mixer 0...

Страница 57: ...ment 3 2 LMIXEN 0 Left output channel mixer enable 0 disabled 1 enabled 3 RMIXEN 0 Right output channel mixer enable 0 disabled 1 enabled Table 38 Left and Right Output Mixer Control HEADPHONE OUTPUTS...

Страница 58: ...0000 57dB 111001 0dB 111111 6dB 8 HPVU Not latched LOUT1 and ROUT1 volumes do not update until a 1 is written to HPVU in reg 52 or 53 R53 ROUT1 Volume control 7 ROUT1ZC 0 Headphone volume zero cross e...

Страница 59: ...mode OUT3BOOST OUT4BOOST 1 then the VMID value of these outputs will be equal to 1 5xAVDD 2 and will not match the VMID of the headphone drivers Do not use the DC coupled output mode in this configur...

Страница 60: ...WM8978 Production Data w PD Rev 4 5 October 2011 60 Figure 29 Speaker Outputs LOUT2 and ROUT2...

Страница 61: ...ts and can be any combination of the DAC output the Bypass path output of the input boost stage and the AUX input The LOUT2 ROUT2 volume is controlled by the LOUT2VOL ROUT2VOL register bits Gains over...

Страница 62: ...RPGA2INV 0 Mute input to INVROUT2 mixer 4 INVROUT2 0 Invert ROUT2 output 3 1 BEEPVOL 000 AUXR input to ROUT2 inverter gain 000 15dB 111 6dB 0 BEEPEN 0 0 mute AUXR beep input 1 enable AUXR beep input T...

Страница 63: ...mixer for OUT3 and one for OUT4 as shown in Figure 31 The OUT3 and OUT4 output stages are powered from SPKVDD and SPKGND The individually controllable outputs also incorporate an optional 1 5x boost...

Страница 64: ...t DAC mixer to OUT4 0 disabled 1 enabled 3 LDAC2OUT4 0 Left DAC to OUT4 0 disabled 1 enabled 2 BYPR2OUT4 0 Right ADC input to OUT4 0 disabled 1 enabled 1 RMIX2OUT4 0 Right DAC mixer to OUT4 0 disabled...

Страница 65: ...1 DC AVDD 2 1 OUT4 output gain 1 5 DC 1 5 x AVDD 2 R1 Power management 1 8 BUFDCOPEN 0 Dedicated buffer for DC level shifting output stages when in 1 5x gain boost configuration 0 Buffer disabled 1 Bu...

Страница 66: ...er path For example DACL can be directly input to the OUT3 mixer giving a 180 phase shift at the OUT3 mixer output However if DACL is input to the OUT3 mixer via the left mixer an additional phase shi...

Страница 67: ...UT1 and LOUT2 ROUT2 and OUT4 OUT3 Speaker boost enabled 0 0 0 1 0 0 0 1 0 1 0 1 0 1 0 1 5 0 1 5 Stereo DAC playback to LOUT1 ROUT1 and LOUT2 ROUT2 and OUT4 OUT3 OUT3 and OUT4 boost enabled 0 0 0 0 1 1...

Страница 68: ...ON 0 OFF Table 49 Output Stages Power Management Control THERMAL SHUTDOWN The speaker outputs can drive very large currents To protect the WM8978 from overheating a thermal shutdown circuit is includ...

Страница 69: ...tput of the DC level shift buffer at 1 5xAVDD 2 when disabled Figure 35 summarises the tie off options for the speaker and mono output pins Figure 35 Unused Input Output Pin Tie off Buffers L ROUT2EN...

Страница 70: ...section for timing information MASTER AND SLAVE MODE OPERATION The WM8978 audio interface may be configured as either master or slave As a master interface device the WM8978 generates BCLK and LRC and...

Страница 71: ...unused BCLK cycles after each LRC transition Figure 37 Right Justified Audio Interface assuming n bit word length In I 2 S mode the MSB is available on the second rising edge of BCLK following a LRC t...

Страница 72: ...selectable by LRP following a rising edge of LRC Right channel data immediately follows left channel data Depending on word length BCLK frequency and sample rate there may be unused BCLK cycles betwe...

Страница 73: ...ode A B select 1 MSB is available o n 1st BCLK rising edge after LRC rising edge mode B 0 MSB is available o n 2nd BCLK rising edge after LRC rising edge mode A 8 BCP BCLK polarity 0 normal 1 inverted...

Страница 74: ...output under control of CLKSEL 000 divide by 1 001 divide by 1 5 010 divide by 2 011 divide by 3 100 divide by 4 101 divide by 6 110 divide by 8 111 divide by 12 8 CLKSEL 1 Controls the source of the...

Страница 75: ...0 48kHz 001 32kHz 010 24kHz 011 16kHz 100 12kHz 101 8kHz 110 111 reserved Table 55 Sample Rate Control MASTER CLOCK AND PHASE LOCKED LOOP PLL The WM8978 has an on chip phase locked loop PLL circuit th...

Страница 76: ...by 4 in the PLL and a selectable divide by N after the PLL which should be set to divide by 2 to meet this requirement Enabling the divide by 2 sets the required f2 4 x 2 x 12 288MHz 98 304MHz R 98 30...

Страница 77: ...09 9 1F76F7 19 8 12 288 98 304 2 2 9 929697 9 EE009E 24 11 29 90 3168 2 2 7 5264 7 86C226 24 12 288 98 304 2 2 8 192 8 3126E8 26 11 29 90 3168 2 2 6 947446 6 F28BD4 26 12 288 98 304 2 2 7 561846 7 8FD...

Страница 78: ...ded by the G 711 standard all 8 bits are inverted for law all even data bits are inverted for A law The data will be transmitted as the first 8 MSB s of data Companding converts 13 bits law or 12 bits...

Страница 79: ...PUT The WM8978 has three dual purpose input output pins CSB GPIO1 CSB GPIO pin L2 GPIO2 Left channel line input headphone detection input R2 GPIO3 Right channel line input headphone detection input Th...

Страница 80: ...output enables from toggling multiple times due to input glitches This de bounce circuit is clocked from a slow clock with period 2 21 x MCLK and is enabled by the SLOWCLKEN bit Notes 1 The SLOWCLKEN...

Страница 81: ...l via the normal output enables found in Table 49 REGISTER ADDRESS BIT LABEL DEFAULT DESCRIPTION R9 GPIO control 5 4 JD_SEL 00 Pin selected as jack detection input 00 GPIO1 01 GPIO2 10 GPIO3 11 Reserv...

Страница 82: ...device address and data will follow All devices on the 2 wire bus respond to the start condition and shift in the next eight bits on SDIN 7 bit address Read Write bit MSB first If the device address...

Страница 83: ...with lower distortion If SPKVDD is lower than AVDD the output signal may be clipped DCVDD Digital core supply powers all digital functions except the audio and control interfaces DCVDD can range from...

Страница 84: ...R1 5 Set SPKBOOST 1 in register R49 6 Set VMIDSEL 1 0 to required value in register R1 Wait for the VMID supply to settle Refer notes 1 and 2 7 Set L RMIXEN 1 and DACENL R 1 in register R3 8 Set BIAS...

Страница 85: ...5 boost mode will cause the VMID voltage to drop to AVDD 2 midrail level and cause an output pop In addition to the power on sequence it is recommended that the zero cross functions are used when cha...

Страница 86: ...is enabled there will be LSB data bit activity on the ADCDAT pin due to system noise but no significant digital output will be present 4 The VMIDSEL and BIASEN bits must be set to enable analogue inpu...

Страница 87: ...p noise on the analogue outputs The same is also true if the DACDAT is removed at a non zero value and no mute function has been applied to the signal beforehand 3 The lineout discharge time tline_mid...

Страница 88: ...e select 0 64x lowest power 1 128x best SNR Table 66 ADC and DAC Oversampling Rate Selection VMID The analogue circuitry will not work when VMID is disabled VMIDSEL 1 0 00b The impedance of the VMID r...

Страница 89: ...tect Control JD_EN1 JD_EN0 000 14 0E ADC Control HPFEN HPFAPP HPFCUT ADCOSR 128 0 ADCRPOL ADCLPOL 100 15 0F Left ADC Digital Vol ADCVU ADCVOLL 0FF 16 10 Right ADC Digital Vol ADCVU ADCVOLR 0FF 18 12 E...

Страница 90: ...OOST OUT3 BOOST SPK BOOST TSDEN VROI 002 50 32 Left mixer ctrl AUXLMIXVOL AUXL2LMIX BYPLMIXVOL BYPL2LMIX DACL2LMIX 001 51 33 Right mixer ctrl AUXRMIXVOL AUXR2RMI X BYPRMIXVOL BYPR2RMIX DACR2RMIX 001 5...

Страница 91: ...Master Clock and Phase Locked Loop PLL 4 MICBEN 0 Microphone Bias Enable 0 OFF high impedance output 1 ON Input Signal Path 3 BIASEN 0 Analogue amplifier bias control 0 disabled 1 enabled Power Manage...

Страница 92: ...d 1 enabled Power Management 3 RMIXEN 0 Right output channel mixer enable 0 disabled 1 enabled Analogue Outputs 2 LMIXEN 0 Left output channel mixer enable 0 disabled 1 enabled Analogue Outputs 1 DACE...

Страница 93: ...e operation Data appears in left phase of LRC Digital Audio Interfaces 5 05h 8 6 000 Reserved 5 WL8 0 Companding Control 8 bit mode 0 off 1 device operates in 8 bit mode Digital Audio Interfaces 4 3 D...

Страница 94: ...configures the coefficients for the internal digital filters 000 48kHz 001 32kHz 010 24kHz 011 16kHz 100 12kHz 101 8kHz 110 111 reserved Audio Sample Rates 0 SLOWCLKEN 0 Slow clock enable Used for bot...

Страница 95: ...Output Signal Path 1 DACPOLR 0 Right DAC output polarity 0 non inverted 1 inverted 180 degrees phase shift Output Signal Path 0 DACPOLL 0 Left DAC output polarity 0 non inverted 1 inverted 180 degree...

Страница 96: ...to Digital Converter ADC 3 ADCOSR 128 0 ADC oversample rate select 0 64x lowest power 1 128x best SNR Power Management 2 0 Reserved 1 ADCRPOL 0 ADC right channel polarity adjust 0 normal 1 inverted A...

Страница 97: ...nal Path 4 0 EQ2G 01100 EQ Band 2 Gain Control See Table 36 for details Output Signal Path 20 14h 8 EQ3BW 0 EQ Band 3 Bandwidth Control 0 narrow bandwidth 1 wide bandwidth Output Signal Path 7 0 Reser...

Страница 98: ...10 768ms Output Signal Path 3 0 LIMATK 0010 DAC Limiter Attack time per 6dB gain change for 44 1kHz sampling Note that these will scale with sample rate 0000 94us 0001 188s 0010 375us 0011 750us 0100...

Страница 99: ...Digital Converter ADC 29 1Dh 8 NFU 0 Notch filter update The notch filter values used internally only update when one of the NFU bits is set high Analogue to Digital Converter ADC 7 0 Reserved 6 0 NFA...

Страница 100: ...Automatic Level Control ALC 34 22h 8 ALCMODE 0 Determines the ALC mode of operation 0 ALC mode 1 Limiter mode Input Limiter Automatic Level Control ALC 7 4 ALCDCY 3 0 0011 Decay gain ramp up time ALCM...

Страница 101: ...se Locked Loop PLL 3 0 PLLN 3 0 1000 Integer N part of PLL input output frequency ratio Use values greater than 5 and less than 13 Master Clock and Phase Locked Loop PLL 37 25h 8 6 000 Reserved 5 0 PL...

Страница 102: ...tive terminal connected to RIP constant input impedance Input Signal Path 3 0 Reserved 2 L2_2INPPGA 0 Connect L2 pin to left channel input PGA positive terminal 0 L2 not connected to input PGA 1 L2 co...

Страница 103: ...el input PGA volume 000000 12dB 000001 11 25db 010000 0dB 111111 35 25dB Input Signal Path 47 2Fh 8 PGABOOSTL 1 Boost enable for left channel input PGA 0 PGA output has 0dB gain through input BOOST st...

Страница 104: ...cted 1 selected Analogue Outputs 5 DACR2LMIX 0 Right DAC output to left output mixer 0 not selected 1 selected Analogue Outputs 4 OUT4BOOST 0 0 OUT4 output gain 1 DC AVDD 2 1 OUT4 output gain 1 5 DC 1...

Страница 105: ...puts 5 AUXR2RMIX 0 Right Auxiliary input to right channel output mixer 0 not selected 1 selected Analogue Outputs 4 2 BYPRMIXVOL 000 Right bypass volume control to output channel mixer 000 15dB 001 12...

Страница 106: ...54 or 55 Analogue Outputs 7 LOUT2ZC 0 Speaker volume zero cross enable 1 Change gain on zero cross only 0 Change gain immediately Analogue Outputs 6 LOUT2MUTE 0 Left speaker output mute 0 Normal opera...

Страница 107: ...57 39h 8 7 00 Reserved 6 OUT4MUTE 0 0 Output stage outputs OUT4 mixer 1 Output stage muted drives out VMID Can be used as VMID buffer in this mode Analogue Outputs 5 HALFSIG 0 0 OUT4 normal output 1...

Страница 108: ...ADC High Pass Filter High Pass Filter Corner Frequency 3dB 3 7 Hz 0 5dB 10 4 0 1dB 21 6 DAC Filter Passband 0 035dB 0 0 454fs 6dB 0 5fs Passband Ripple 0 035 dB Stopband 0 546fs Stopband Attenuation...

Страница 109: ...e 128xOSR 160 140 120 100 80 60 40 20 0 20 0 0 5 1 1 5 2 2 5 Frequency fs Response dB 2 6 2 65 2 7 2 75 2 8 2 85 2 9 2 95 3 3 05 0 0 05 0 1 0 15 0 2 0 25 0 3 0 35 0 4 0 45 0 5 Frequency fs Response dB...

Страница 110: ...0 5 0 5 10 15 20 25 30 35 40 45 Frequency Hz Response dB Figure 54 ADC Highpass Filter Response HPFAPP 0 60 50 40 30 20 10 0 10 0 200 400 600 800 1000 1200 Frequency Hz Response dB 80 70 60 50 40 30 2...

Страница 111: ...0 0 10 1 10 2 10 3 10 4 10 5 15 10 5 0 5 10 15 Frequency Hz Magnitude dB 10 1 10 0 10 1 10 2 10 3 10 4 10 5 15 10 5 0 5 10 15 Frequency Hz Magnitude dB Figure 58 EQ Band 1 Low Frequency Shelf Filter C...

Страница 112: ...dB 10 1 10 0 10 1 10 2 10 3 10 4 10 5 15 10 5 0 5 10 15 Frequency Hz Magnitude dB Figure 63 EQ Band 3 Peak Filter Centre Frequencies EQ3B Figure 64 EQ Band 3 Peak Filter Gains for Lowest Cut off Freq...

Страница 113: ...Q3B Figure 67 EQ Band 4 Peak Filter Gains for Lowest Cut off Frequency EQ4BW 0 10 2 10 1 10 0 10 1 10 2 10 3 10 4 15 10 5 0 5 10 15 Frequency Hz Magnitude dB Figure 68 EQ Band 4 EQ3BW 0 EQ3BW 1 10 1 1...

Страница 114: ...eously The blue traces show each band lowest cut off centre frequency with 12dB gain The red traces show the cumulative effect of all bands with 12dB gain and all bands 12dB gain with EqxBW 0 for the...

Страница 115: ...Production Data WM8978 w PD Rev 4 5 October 2011 115 APPLICATION INFORMATION RECOMMENDED EXTERNAL COMPONENTS Figure 72 Recommended External Component Diagram...

Страница 116: ...HALL CONFORM TO JEDEC 95 1 SPP 002 5 COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS 6 REFER TO APPLICATION NOTE WAN_0118 FOR FURTHER INFORMATION REGARDING PCB FOOTPRINTS AN...

Страница 117: ...ms 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...

Страница 118: ...REVISION HISTORY DATE REV ORIGINATOR CHANGES 26 09 11 4 5 JMacD Order codes changed from WM8978GEFL V and WM8978GEFL RV to WM8978CGEFL V and WM8978CGEFL RV to reflect change to copper wire bonding 26...

Страница 119: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Cirrus Logic WM8978CGEFL V WM8978CGEFL RV WM8978GEFL V...

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