SigmaDSP Stereo, Low Power, 96 kHz, 24-Bit Audio Codec with Integrated PLL ADAU1761 FEATURES GENERAL DESCRIPTION SigmaDSP 28-/56-bit, 50 MIPS digital audio processor Fully programmable with SigmaStudio graphical tool 24-bit stereo audio ADC and DAC: >98 dB SNR Sampling rates from 8 kHz to 96 kHz Low power: 7 mW record, 7 mW playback, 48 kHz at 1.8 V 6 analog input pins, configurable for single-ended or differential inputs Flexible analog input/output mixers Stereo digital microphone input Analog outputs: 2 differential stereo, 2 single-ended stereo, 1 mono headphone output driver PLL supporting input clocks from 8 MHz to 27 MHz Analog automatic level control (ALC) Microphone bias reference voltage Analog and digital I/O: 1.8 V to 3.65 V I2C and SPI control interfaces Digital audio serial data I/O: stereo and time-division multiplexing (TDM) modes Software-controllable clickless mute Software power-down GPIO pins for digital controls and outputs 32-lead, 5 mm × 5 mm LFCSP −40°C to +85°C operating temperature range The ADAU1761 is a low power, stereo audio codec with integrated digital audio processing that supports stereo 48 kHz record and playback at 14 mW from a 1.8 V analog supply. The stereo audio ADCs and DACs support sample rates from 8 kHz to 96 kHz as well as a digital volume control. The SigmaDSP® core features 28-bit processing (56-bit double precision). The processor allows system designers to compensate for the real-world limitations of microphones, speakers, amplifiers, and listening environments, resulting in a dramatic improvement in the perceived audio quality through equalization, multiband compression, limiting, and third-party branded algorithms. The SigmaStudio™ graphical development tool is used to program the ADAU1761. This software includes audio processing blocks such as filters, dynamics processors, mixers, and low level DSP functions for fast development of custom signal flows. The record path includes an integrated microphone bias circuit and six inputs. The inputs can be mixed and muxed before the ADC, or they can be configured to bypass the ADC. The ADAU1761 includes a stereo digital microphone input. The ADAU1761 includes five high power output drivers (two differential and three single-ended), supporting stereo headphones, an earpiece, or other output transducer. AC-coupled or capless configurations are supported. Individual fine level controls are supported on all analog outputs. The output mixer stage allows for flexible routing of audio. APPLICATIONS Smartphones/multimedia phones Digital still cameras/digital video cameras Portable media players/portable audio players Phone accessories products HP JACK DETECTION JACKDET/MICIN AGND AGND AVDD AVDD DVDDOUT DGND IOVDD CM FUNCTIONAL BLOCK DIAGRAM ADAU1761 REGULATOR LAUX LOUTP LINN INPUT MIXERS RINP ALC ADC ADC DAC DIGITAL DIGITAL FILTERS FILTERS ADC LOUTN DAC DAC LHP OUTPUT MIXERS MONOOUT RHP RINN ROUTP RAUX ROUTN DAC_SDATA/ GPIO0 MCLK SERIAL DATA INPUT/OUTPUT PORTS LRCLK/ GPIO3 PLL BCLK/ GPIO2 MICROPHONE BIAS ADC_SDATA/ GPIO1 MICBIAS I2C/SPI CONTROL PORT ADDR0/ ADDR1/ SCL/ SDA/ CLATCH CDATA CCLK COUT 07680-001 LINP Figure 1. Rev. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2009–2010 Analog Devices, Inc. All rights reserved. ADAU1761 TABLE OF CONTENTS Features .............................................................................................. 1 Playback Signal Path ...................................................................... 35 Applications....................................................................................... 1 Output Signal Paths ................................................................... 35 General Description ......................................................................... 1 Headphone Output .................................................................... 36 Functional Block Diagram .............................................................. 1 Pop-and-Click Suppression ...................................................... 37 Revision History ............................................................................... 3 Line Outputs ............................................................................... 37 Specifications..................................................................................... 4 Control Ports................................................................................... 38 Analog Performance Specifications ........................................... 4 Burst Mode Writing and Reading ............................................ 38 Power Supply Specifications........................................................ 7 I2C Port ........................................................................................ 38 Typical Current Consumption.................................................... 8 SPI Port ........................................................................................ 41 Typical Power Management Measurements ............................. 9 Serial Data Input/Output Ports .................................................... 42 Digital Filters............................................................................... 10 Applications Information .............................................................. 44 Digital Input/Output Specifications......................................... 10 Power Supply Bypass Capacitors.............................................. 44 Digital Timing Specifications ................................................... 11 GSM Noise Filter ........................................................................ 44 Digital Timing Diagrams........................................................... 12 Grounding ................................................................................... 44 Absolute Maximum Ratings.......................................................... 14 Exposed Pad PCB Design ......................................................... 44 Thermal Resistance .................................................................... 14 DSP Core ......................................................................................... 45 ESD Caution................................................................................ 14 Signal Processing........................................................................ 45 Pin Configuration and Function Descriptions........................... 15 Architecture ................................................................................ 45 Typical Performance Characteristics ........................................... 17 Program Counter ....................................................................... 45 System Block Diagrams ................................................................. 20 Features........................................................................................ 45 Theory of Operation ...................................................................... 23 Startup.......................................................................................... 45 Startup, Initialization, and Power ................................................. 24 Numeric Formats ....................................................................... 46 Power-Up Sequence ................................................................... 24 Programming.............................................................................. 46 Power Reduction Modes............................................................ 24 Program RAM, Parameter RAM, and Data RAM ..................... 47 Digital Power Supply.................................................................. 24 Program RAM ............................................................................ 47 Input/Output Power Supply...................................................... 24 Parameter RAM.......................................................................... 47 Clock Generation and Management........................................ 24 Data RAM ................................................................................... 47 Clocking and Sampling Rates ....................................................... 26 Read/Write Data Formats ......................................................... 47 Core Clock................................................................................... 26 Software Safeload ....................................................................... 48 Sampling Rates............................................................................ 27 Software Slew .............................................................................. 49 PLL ............................................................................................... 27 General-Purpose Input/Output.................................................... 50 Record Signal Path.......................................................................... 29 GPIO Pins Set from the Control Port...................................... 50 Input Signal Paths....................................................................... 29 Control Registers ............................................................................ 51 Analog-to-Digital Converters................................................... 31 Control Register Details ............................................................ 52 Automatic Level Control (ALC) ................................................... 32 Outline Dimensions ....................................................................... 92 ALC Parameters.......................................................................... 32 Ordering Guide .......................................................................... 92 Noise Gate Function .................................................................. 33 Rev. C | Page 2 of 92 ADAU1761 REVISION HISTORY 9/10—Rev. B to Rev. C Changes to Figure 1...........................................................................1 5/10—Rev. A to Rev. B Changes to Burst Mode Writing and Reading Section ..............38 Changes to Table 33 ........................................................................51 Added R67: Dejitter Control, 16,438 (0x4036) Section .............79 12/09—Rev. 0 to Rev. A Changes to Features Section ............................................................1 Change to General Description Section.........................................1 Changes to Table 1 ............................................................................6 Change to Table 5 ............................................................................10 Changes to Figure 6.........................................................................13 Changes to Table 10 ........................................................................15 Changes to Captions of Figure 15, Figure 16, Figure 18, and Figure 19 ...........................................................................................18 Changes to Captions of Figure 21 and Figure 24 ........................19 Added Figure 25; Renumbered Sequentially ...............................19 Change to Figure 26 ........................................................................20 Change to Figure 27 ........................................................................21 Change to Figure 28 ........................................................................22 Change to Theory of Operation Section ......................................23 Changes to Power Reduction Modes Section and Case 1: PLL Is Bypassed Section ...................................................24 Changes to PLL Lock Acquisition Section...................................25 Changes to Core Clock Section and Figure 30............................26 Change to Sampling Rates Section................................................27 Changes to Input Signal Paths Section and Figure 32................29 Changes to Figure 33 and Figure 34 .............................................30 Changes to ADC Full-Scale Level Section ...................................31 Change to Automatic Level Control (ALC) Section...................32 Changes to Output Signal Paths Section......................................35 Changes to Headphone Output Section.......................................36 Changes to Jack Detection Section, Pop-and-Click Suppression Section, and Line Outputs Section .........................37 Changes to Control Ports Section and I2C Port Section ............38 Added Burst Mode Writing and Reading Section ......................38 Changes to SPI Port Section ..........................................................41 Changes to Serial Data Input/Output Ports Section and Table 25 .....................................................................................42 Added Figure 57 ..............................................................................42 Changes to Architecture Section and Figure 67..........................45 Added Startup Section....................................................................45 Changes to Parameter RAM Section and Data RAM Section ..47 Changes to Table 33 ........................................................................51 Changes to R2: Digital Microphone/Jack Detection Control, 16,392 (0x4008) Section and Table 36..........................................54 Changes to Table 42 ........................................................................58 Changes to Table 43 ........................................................................59 Changes to R15: Serial Port Control 0, 16,405 (0x4015) Section and Table 49 .......................................................................63 Change to Table 50..........................................................................64 Changes to Table 51, R18: Converter Control 1, 16,408 (0x4018) Section, and Table 52 .....................................................65 Changes to Table 60, R27: Playback L/R Mixer Right (Mixer 6) Line Output Control, 16,417 (0x4021) Section, and Table 61...71 Changes to Table 62, R29: Playback Headphone Left Volume Control, 16,419 (0x4023) Section, and Table 63 .........................72 Changes to Table 64 ........................................................................73 Changes to R42: Jack Detect Pin Control, 16,433 (0x4031) Section and Table 76 .......................................................................79 Changes to R57: DSP Sampling Rate Setting, 16,619 (0x40EB) Section and Table 81 .......................................................................81 Change to Table 85..........................................................................83 Change to Table 88..........................................................................84 Changes to R66: Clock Enable 1, 16,634 (0x40FA) Section and Table 90 .....................................................................................85 1/09—Revision 0: Initial Version Rev. C | Page 3 of 92 ADAU1761 SPECIFICATIONS Supply voltage (AVDD) = 3.3 V, TA = 25°C, master clock = 12.288 MHz (48 kHz fS, 256 × fS mode), input sample rate = 48 kHz, measurement bandwidth = 20 Hz to 20 kHz, word width = 24 bits, CLOAD (digital output) = 20 pF, ILOAD (digital output) = 2 mA, VIH = 2 V, VIL = 0.8 V, unless otherwise noted. Performance of all channels is identical, exclusive of the interchannel gain mismatch and interchannel phase deviation specifications. ANALOG PERFORMANCE SPECIFICATIONS Specifications guaranteed at 25°C (ambient). Table 1. Parameter ANALOG-TO-DIGITAL CONVERTERS ADC Resolution Digital Attenuation Step Digital Attenuation Range INPUT RESISTANCE Single-Ended Line Input PGA Inverting Inputs PGA Noninverting Inputs SINGLE-ENDED LINE INPUT Full-Scale Input Voltage (0 dB) Dynamic Range With A-Weighted Filter (RMS) No Filter (RMS) Total Harmonic Distortion + Noise Signal-to-Noise Ratio With A-Weighted Filter (RMS) No Filter (RMS) Gain per Step Total Gain Range Mute Attenuation Interchannel Gain Mismatch Offset Error Gain Error Interchannel Isolation Power Supply Rejection Ratio Test Conditions/Comments ADC performance excludes mixers and PGA All ADCs Min Typ Max Unit 24 0.375 95 Bits dB dB −12 dB gain 0 dB gain 6 dB gain −12 dB gain 0 dB gain 35.25 dB gain All gains 83 21 10.5 84.5 53 2 105 kΩ kΩ kΩ kΩ kΩ kΩ kΩ Scales linearly with AVDD AVDD = 1.8 V AVDD = 3.3 V 20 Hz to 20 kHz, −60 dB input AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V −1 dBFS AVDD = 1.8 V AVDD = 3.3 V AVDD/3.3 0.55 (1.56) 1.0 (2.83) V rms V rms (V p-p) V rms (V p-p) 94 99 91 96 dB dB dB dB −88 −90 dB dB 94 99 91 96 3 −87 0.005 0 −12 68 dB dB dB dB dB dB dB dB mV % dB 65 67 dB dB AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V −12 CM capacitor = 20 μF 100 mV p-p @ 217 Hz 100 mV p-p @ 1 kHz Rev. C | Page 4 of 92 +6 ADAU1761 Parameter PSEUDO-DIFFERENTIAL PGA INPUT Full-Scale Input Voltage (0 dB) Dynamic Range With A-Weighted Filter (RMS) No Filter (RMS) Total Harmonic Distortion + Noise Signal-to-Noise Ratio With A-Weighted Filter (RMS) No Filter (RMS) Volume Control Step Volume Control Range PGA Boost Mute Attenuation Interchannel Gain Mismatch Offset Error Gain Error Interchannel Isolation Common-Mode Rejection Ratio FULL DIFFERENTIAL PGA INPUT Full-Scale Input Voltage (0 dB) Dynamic Range With A-Weighted Filter (RMS) No Filter (RMS) Total Harmonic Distortion + Noise Signal-to-Noise Ratio With A-Weighted Filter (RMS) No Filter (RMS) Volume Control Step Volume Control Range PGA Boost Mute Attenuation Interchannel Gain Mismatch Offset Error Gain Error Test Conditions/Comments Min Scales linearly with AVDD AVDD = 1.8 V AVDD = 3.3 V 20 Hz to 20 kHz, −60 dB input AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V −1 dBFS AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V PGA gain PGA gain Typ AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V PGA gain PGA gain V rms V rms (V p-p) V rms (V p-p) 92 98 90 95 dB dB dB dB −88 −89 dB dB 92 98 90 95 0.75 20 −87 0.005 0 −14 83 65 65 dB dB dB dB dB dB dB dB dB mV % dB dB dB AVDD/3.3 0.55 (1.56) 1.0 (2.83) V rms V rms (V p-p) V rms (V p-p) 92 98 90 95 dB dB dB dB −70 −78 dB dB 92 98 90 95 0.75 dB dB dB dB dB dB dB dB dB mV % +35.25 −12 +35.25 20 −87 0.005 0 −14 Rev. C | Page 5 of 92 Unit AVDD/3.3 0.55 (1.56) 1.0 (2.83) −12 100 mV rms, 1 kHz 100 mV rms, 20 kHz Differential PGA inputs Scales linearly with AVDD AVDD = 1.8 V AVDD = 3.3 V 20 Hz to 20 kHz, −60 dB input AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V −1 dBFS AVDD = 1.8 V AVDD = 3.3 V Max ADAU1761 Parameter Interchannel Isolation Common-Mode Rejection Ratio MICROPHONE BIAS Bias Voltage 0.65 × AVDD 0.90 × AVDD Bias Current Source Noise in the Signal Bandwidth DIGITAL-TO-ANALOG CONVERTERS DAC Resolution Digital Attenuation Step Digital Attenuation Range DAC TO LINE OUTPUT Full-Scale Output Voltage (0 dB) Analog Volume Control Step Analog Volume Control Range Mute Attenuation Dynamic Range With A-Weighted Filter (RMS) No Filter (RMS) Total Harmonic Distortion + Noise Signal-to-Noise Ratio With A-Weighted Filter (RMS) No Filter (RMS) Power Supply Rejection Ratio Gain Error Interchannel Gain Mismatch Offset Error Interchannel Isolation Test Conditions/Comments Min 100 mV rms, 1 kHz 100 mV rms, 20 kHz MBIEN = 1 AVDD = 1.8 V, MBI = 1 AVDD = 3.3 V, MBI = 1 AVDD = 1.8 V, MBI = 0 AVDD = 3.3 V, MBI = 0 AVDD = 3.3 V, MBI = 0, MPERF = 1 AVDD = 3.3 V, 1 kHz to 20 kHz MBI = 0, MPERF = 0 MBI = 0, MPERF = 1 MBI = 1, MPERF = 0 MBI = 1, MPERF = 1 DAC performance excludes mixers and headphone amplifier All DACs Scales linearly with AVDD AVDD = 1.8 V AVDD = 3.3 V Line output volume control Line output volume control 20 Hz to 20 kHz, −60 dB input, line output mode AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V −1 dBFS, line output mode AVDD = 1.8 V AVDD = 3.3 V Line output mode AVDD = 1.8 V AVDD = 3.3 V AVDD = 1.8 V AVDD = 3.3 V CM capacitor = 20 μF 100 mV p-p @ 217 Hz 100 mV p-p @ 1 kHz 1 kHz, 0 dBFS input signal Rev. C | Page 6 of 92 Typ 83 65 65 Max 1.17 2.145 1.62 2.97 3 −57 Unit dB dB dB V V V V mA 42 85 25 37 nV/√Hz nV/√Hz nV/√Hz nV/√Hz 24 0.375 95 Bits dB dB AVDD/3.3 0.50 (1.41) 0.92 (2.60) 0.75 1 −87 V rms V rms (V p-p) V rms (V p-p) dB dB dB 96 101 93.5 98 +6 −90 −92 dB dB dB dB dB dB dB 96 101 93.5 98 dB dB dB dB 56 70 3 0.005 0 100 dB dB % dB mV dB ADAU1761 Parameter DAC TO HEADPHONE/EARPIECE OUTPUT Full-Scale Output Voltage (0 dB) Total Harmonic Distortion + Noise 16 Ω load 32 Ω load Power Supply Rejection Ratio Interchannel Isolation REFERENCE Common-Mode Reference Output Test Conditions/Comments PO = output power per channel Min Scales linearly with AVDD AVDD = 1.8 V AVDD = 3.3 V −4 dBFS AVDD = 1.8 V, PO = 6.4 mW AVDD = 3.3 V, PO = 21.1 mW AVDD = 1.8 V, PO = 3.8 mW AVDD = 3.3 V, PO = 10.6 mW CM capacitor = 20 μF 100 mV p-p @ 217 Hz 100 mV p-p @ 1 kHz 1 kHz, 0 dBFS input signal, 32 Ω load, AVDD = 3.3 V Referred to GND Referred to CM (capless headphone mode) CM pin Typ Max Unit AVDD/3.3 0.50 (1.41) 0.92 (2.60) V rms V rms (V p-p) V rms (V p-p) −76 −82 −82 −82 dB dB dB dB 56 67 dB dB 73 50 dB dB AVDD/2 V POWER SUPPLY SPECIFICATIONS Table 2. Parameter SUPPLIES Voltage Digital I/O Current (IOVDD = 1.8 V) Slave Mode Master Mode Digital I/O Current (IOVDD = 3.3 V) Slave Mode Master Mode Analog Current (AVDD) Test Conditions/Comments DVDDOUT AVDD IOVDD 20 pF capacitive load on all digital pins fS = 48 kHz fS = 96 kHz fS = 8 kHz fS = 48 kHz fS = 96 kHz fS = 8 kHz 20 pF capacitive load on all digital pins fS = 48 kHz fS = 96 kHz fS = 8 kHz fS = 48 kHz fS = 96 kHz fS = 8 kHz See Table 3 Rev. C | Page 7 of 92 Min Typ Max Unit 1.8 1.63 1.56 3.3 3.3 3.65 3.65 V V V 0.25 0.48 0.07 0.62 1.23 0.11 mA mA mA mA mA mA 0.48 0.9 0.13 1.51 3 0.27 mA mA mA mA mA mA ADAU1761 TYPICAL CURRENT CONSUMPTION Master clock = 12.288 MHz, input sample rate = 48 kHz, input tone = 1 kHz, normal power management settings, ADC input @ −1 dBFS, DAC input @ 0 dBFS. For total power consumption, add the IOVDD current listed in Table 2. Table 3. Operating Voltage AVDD = IOVDD = 3.3 V Audio Path Record stereo differential to ADC DAC stereo playback to line output (10 kΩ) DAC stereo playback to headphone (16 Ω) DAC stereo playback to headphone (32 Ω) DAC stereo playback to capless headphone (32 Ω) Record aux stereo bypass to line output (10 kΩ) AVDD = IOVDD = 1.8 V Record stereo differential to ADC DAC stereo playback to line output (10 kΩ) DAC stereo playback to headphone (16 Ω) DAC stereo playback to headphone (32 Ω) DAC stereo playback to capless headphone (32 Ω) Record aux stereo bypass to line output (10 kΩ) Rev. C | Page 8 of 92 Clock Generation Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Direct MCLK Integer PLL Typical AVDD Current Consumption (mA) 5.24 6.57 5.55 6.90 55.5 56.8 30.9 32.25 56.75 58 1.9 3.3 4.25 5.55 4.7 5.7 30.81 32 18.3 19.5 32.6 33.7 1.9 3.07 ADAU1761 TYPICAL POWER MANAGEMENT MEASUREMENTS Master clock = 12.288 MHz, integer PLL, input sample rate = 48 kHz, input tone = 1 kHz. Pseudo-differential input to ADCs, DACs to line output with 10 kΩ load. ADC input @ −1 dBFS, DAC input @ 0 dBFS. In Table 4, the mixer boost and power management conditions are set for MXBIAS[1:0], ADCBIAS[1:0], HPBIAS[1:0], and DACBIAS[1:0]. RBIAS[1:0] and PBIAS[1:0] do not have an extreme power saving mode and are therefore set for power saving mode in the extreme power saving rows in Table 4. Table 4. Operating Voltage AVDD = IOVDD = 3.3 V Power Management Setting Normal (default) Extreme power saving Power saving Enhanced performance AVDD = IOVDD = 1.8 V Normal (default) Extreme power saving Power saving Enhanced performance Mixer Boost Setting Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Normal operation Boost Level 1 Boost Level 2 Boost Level 3 Typical AVDD Current Consumption (mA) 9.6 9.75 9.92 10.25 7.09 7.19 7.29 7.49 7.67 7.77 7.86 8.07 10.55 10.74 10.93 11.33 8.1 8.26 8.41 8.73 5.73 5.82 5.91 6.1 6.27 6.36 6.46 6.65 9.01 9.2 9.38 9.76 Rev. C | Page 9 of 92 Typical ADC THD + N (dB) −91 −91.5 −91.5 −91.5 −84.5 −84.8 −84.8 −85 −89.5 −89.5 −89.8 −89.8 −91 −91 −91 −91 −88 −88 −88 −88 −85 −85.4 −85.5 −85.5 −86 −86.1 −86.3 −86.3 −88 −88 −88 −88 Typical Line Output THD + N (dB) −92.5 −92.5 −92.5 −92.5 −87 −87.1 −87.1 −87.1 −90 −90 −90 −90 −93.5 −93.5 −93.5 −93.5 −91.2 −91.2 −91.2 −91.2 −86 −86 −86 −86 −89.4 −89.5 −89.5 −89.5 −91.5 −91.5 −91.5 −91.5 ADAU1761 DIGITAL FILTERS Table 5. Parameter ADC DECIMATION FILTER Pass Band Pass-Band Ripple Transition Band Stop Band Stop-Band Attenuation Group Delay DAC INTERPOLATION FILTER Pass Band Pass-Band Ripple Transition Band Stop Band Stop-Band Attenuation Group Delay Mode All modes, typ @ 48 kHz Factor Min 0.4375 fS Max Unit 22.9844/fS 21 ±0.015 24 27 67 479 kHz dB kHz kHz dB μs 0.4535 fS 0.3646 fS 22 35 kHz kHz dB dB kHz kHz kHz kHz dB dB μs μs 0.5 fS 0.5625 fS 48 kHz mode, typ @ 48 kHz 96 kHz mode, typ @ 96 kHz 48 kHz mode, typ @ 48 kHz 96 kHz mode, typ @ 96 kHz 48 kHz mode, typ @ 48 kHz 96 kHz mode, typ @ 96 kHz 48 kHz mode, typ @ 48 kHz 96 kHz mode, typ @ 96 kHz 48 kHz mode, typ @ 48 kHz 96 kHz mode, typ @ 96 kHz 48 kHz mode, typ @ 48 kHz 96 kHz mode, typ @ 96 kHz Typ ±0.01 ±0.05 0.5 fS 0.5 fS 0.5465 fS 0.6354 fS 24 48 26 61 69 68 521 115 25/fS 11/fS DIGITAL INPUT/OUTPUT SPECIFICATIONS −40°C < TA < +85°C, IOVDD = 3.3 V ± 10%. Table 6. Parameter INPUT SPECIFICATIONS Input Voltage High (VIH) Input Voltage Low (VIL) Input Leakage Pull-Ups/Pull-Downs Disabled Pull-Ups Enabled Pull-Downs Enabled Input Capacitance OUTPUT SPECIFICATIONS Output Voltage High (VOH) Output Voltage Low (VOL) Test Conditions/Comments Min Typ Max Unit 0.3 × IOVDD V V +0.17 +0.17 −0.5 +0.7 −0.5 8.3 +0.18 5 μA μA μA μA μA μA μA pF 0.1 × IOVDD V V 0.7 × IOVDD IIH @ VIH = 3.3 V IIL @ VIL = 0 V IIL @ VIL = 0 V (MCLK pin) IIH @ VIH = 3.3 V IIL @ VIL = 0 V IIH @ VIH = 3.3 V IIL @ VIL = 0 V −0.17 −0.17 −13.5 −0.7 −13.5 2.7 −0.18 IOH = 2 mA @ 3.3 V, 0.85 mA @ 1.8 V IOL = 2 mA @ 3.3 V, 0.85 mA @ 1.8 V 0.8 × IOVDD Rev. C | Page 10 of 92 ADAU1761 DIGITAL TIMING SPECIFICATIONS −40°C < TA < +85°C, IOVDD = 3.3 V ± 10%. Table 7. Digital Timing Parameter MASTER CLOCK tMP tMP tMP tMP SERIAL PORT tBIL tBIH tLIS tLIH tSIS tSIH tSODM SPI PORT fCCLK tCCPL tCCPH tCLS tCLH tCLPH tCDS tCDH tCOD I2C PORT fSCL tSCLH tSCLL tSCS tSCH tDS tSCR tSCF tSDR tSDF tBFT DIGITAL MICROPHONE tDCF tDCR tDDV tDDH tMIN 74 37 24.7 18.5 Limit tMAX Unit Description 488 244 162.7 122 ns ns ns ns MCLK period, 256 × fS mode. MCLK period, 512 × fS mode. MCLK period, 768 × fS mode. MCLK period, 1024 × fS mode. 50 ns ns ns ns ns ns ns BCLK pulse width low. BCLK pulse width high. LRCLK setup. Time to BCLK rising. LRCLK hold. Time from BCLK rising. DAC_SDATA setup. Time to BCLK rising. DAC_SDATA hold. Time from BCLK rising. ADC_SDATA delay. Time from BCLK falling in master mode. MHz ns ns ns ns ns ns ns ns CCLK frequency. CCLK pulse width low. CCLK pulse width high. CLATCH setup. Time to CCLK rising. CLATCH hold. Time from CCLK rising. CLATCH pulse width high. CDATA setup. Time to CCLK rising. CDATA hold. Time from CCLK rising. COUT three-stated. Time from CLATCH rising. kHz μs μs μs μs ns ns ns ns ns μs SCL frequency. SCL high. SCL low. Setup time; relevant for repeated start condition. Hold time. After this period, the first clock is generated. Data setup time. SCL rise time. SCL fall time. SDA rise time. SDA fall time. Bus-free time. Time between stop and start. RLOAD = 1 MΩ, CLOAD = 14 pF. Digital microphone clock fall time. Digital microphone clock rise time. Digital microphone delay time for valid data. Digital microphone delay time for data three-stated. 5 5 5 5 5 5 10 10 10 5 10 10 5 5 50 400 0.6 1.3 0.6 0.6 100 300 300 300 300 0.6 22 0 10 10 30 12 ns ns ns ns Rev. C | Page 11 of 92 ADAU1761 DIGITAL TIMING DIAGRAMS tLIH tBIH BCLK tBIL tLIS LRCLK tSIS DAC_SDATA LEFT-JUSTIFIED MODE MSB MSB – 1 tSIH tSIS DAC_SDATA I2S MODE MSB tSIH tSIS tSIS DAC_SDATA RIGHT-JUSTIFIED MODE LSB MSB tSIH tSIH 8-BIT CLOCKS (24-BIT DATA) 12-BIT CLOCKS (20-BIT DATA) 07680-002 14-BIT CLOCKS (18-BIT DATA) 16-BIT CLOCKS (16-BIT DATA) Figure 2. Serial Input Port Timing tBIH BCLK tBIL LRCLK ADC_SDATA LEFT-JUSTIFIED MODE tSODM MSB MSB – 1 tSODM ADC_SDATA I2S MODE MSB tSODM ADC_SDATA RIGHT-JUSTIFIED MODE MSB LSB 8-BIT CLOCKS (24-BIT DATA) 12-BIT CLOCKS (20-BIT DATA) 07680-003 14-BIT CLOCKS (18-BIT DATA) 16-BIT CLOCKS (16-BIT DATA) Figure 3. Serial Output Port Timing Rev. C | Page 12 of 92 ADAU1761 tCLS tCLH tCLPH tCCPL tCCPH CLATCH CCLK CDATA tCDH tCDS COUT 07680-004 tCOD Figure 4. SPI Port Timing tDS tSCH tSCH SDA tSCLH SCL tSCLL tSCS tSCF tBFT Figure 5. I2C Port Timing tDCF tDCR CLK DATA1/ DATA2 DATA1 DATA2 tDDH tDDV tDDV DATA1 DATA2 Figure 6. Digital Microphone Timing Rev. C | Page 13 of 92 07680-006 tDDH 07680-005 tSCR ADAU1761 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 8. Parameter Power Supply (AVDD) Input Current (Except Supply Pins) Analog Input Voltage (Signal Pins) Digital Input Voltage (Signal Pins) Operating Temperature Range Storage Temperature Range Rating −0.3 V to +3.65 V ±20 mA −0.3 V to AVDD + 0.3 V −0.3 V to IOVDD + 0.3 V −40°C to +85°C −65°C to +150°C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. θJA represents thermal resistance, junction-to-ambient; θJC represents thermal resistance, junction-to-case. All characteristics are for a 4-layer board. Table 9. Thermal Resistance Package Type 32-Lead LFCSP ESD CAUTION Rev. C | Page 14 of 92 θJA 50.1 θJC 17 Unit °C/W ADAU1761 32 31 30 29 28 27 26 25 SCL/CCLK SDA/COUT ADDR1/CDATA LRCLK/GPIO3 BCLK/GPIO2 DAC_SDATA/GPIO0 ADC_SDATA/GPIO1 DGND PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 1 2 3 4 5 6 7 8 PIN 1 INDICATOR ADAU1761 TOP VIEW (Not to Scale) 24 23 22 21 20 19 18 17 DVDDOUT AVDD AGND MONOOUT LHP RHP LOUTP LOUTN NOTES 1. THE EXPOSED PAD IS CONNECTED INTERNALLY TO THE ADAU1761 GROUNDS. FOR INCREASED RELIABILITY OF THE SOLDER JOINTS AND MAXIMUM THERMAL CAPABILITY, IT IS RECOMMENDED THAT THE PAD BE SOLDERED TO THE GROUND PLANE. 07680-007 AGND LINP LINN RINP RINN RAUX ROUTP ROUTN 9 10 11 12 13 14 15 16 IOVDD MCLK ADDR0/CLATCH JACKDET/MICIN MICBIAS LAUX CM AVDD Figure 7. Pin Configuration Table 10. Pin Function Descriptions Pin No. 1 Mnemonic IOVDD Type 1 PWR 2 3 MCLK ADDR0/CLATCH D_IN D_IN 4 JACKDET/MICIN D_IN 5 6 7 MICBIAS LAUX CM A_OUT A_IN A_OUT 8 AVDD PWR 9 AGND PWR 10 11 12 13 14 15 16 17 18 LINP LINN RINP RINN RAUX ROUTP ROUTN LOUTN LOUTP A_IN A_IN A_IN A_IN A_IN A_OUT A_OUT A_OUT A_OUT Description Supply for Digital Input and Output Pins. The digital output pins are supplied from IOVDD, which also sets the highest input voltage that should be seen on the digital input pins. IOVDD should be set between 1.8 V and 3.3 V. The current draw of this pin is variable because it is dependent on the loads of the digital outputs. IOVDD should be decoupled to DGND with a 100 nF capacitor and a 10 μF capacitor. External Master Clock Input. I2C Address Bit 0 (ADDR0). SPI Latch Signal (CLATCH). Must go low at the beginning of an SPI transaction and high at the end of a transaction. Each SPI transaction can take a different number of CCLKs to complete, depending on the address and read/write bit that are sent at the beginning of the SPI transaction. Detect Insertion/Removal of Headphone Plug (JACKDET). Digital Microphone Stereo Input (MICIN). Bias Voltage for Electret Microphone. Left Channel Single-Ended Auxiliary Input. Biased at AVDD/2. AVDD/2 V Common-Mode Reference. A 10 μF to 47 μF standard decoupling capacitor should be connected between this pin and AGND to reduce crosstalk between the ADCs and DACs. This pin can be used to bias external analog circuits, as long as they are not drawing current from CM (for example, the noninverting input of an op amp). 1.8 V to 3.65 V Analog Supply for DAC and Microphone Bias. This pin should be decoupled locally to AGND with a 100 nF capacitor. Analog Ground. The AGND and DGND pins can be tied together on a common ground plane. AGND should be decoupled locally to AVDD with a 100 nF capacitor. Left Channel Noninverting Input or Single-Ended Input 0. Biased at AVDD/2. Left Channel Inverting Input or Single-Ended Input 1. Biased at AVDD/2. Right Channel Noninverting Input or Single-Ended Input 2. Biased at AVDD/2. Right Channel Inverting Input or Single-Ended Input 3. Biased at AVDD/2. Right Channel Single-Ended Auxiliary Input. Biased at AVDD/2. Right Line Output, Positive. Biased at AVDD/2. Right Line Output, Negative. Biased at AVDD/2. Left Line Output, Negative. Biased at AVDD/2. Left Line Output, Positive. Biased at AVDD/2. Rev. C | Page 15 of 92 ADAU1761 Pin No. 19 20 21 Mnemonic RHP LHP MONOOUT Type 1 A_OUT A_OUT A_OUT 22 AGND PWR 23 AVDD PWR 24 DVDDOUT PWR 25 DGND PWR 26 ADC_SDATA/GPIO1 D_IO 27 DAC_SDATA/GPIO0 D_IO 28 BCLK/GPIO2 D_IO 29 LRCLK/GPIO3 D_IO 30 ADDR1/CDATA D_IN 31 SDA/COUT D_IO 32 SCL/CCLK D_IN EP Exposed Pad 1 Description Right Headphone Output. Biased at AVDD/2. Left Headphone Output. Biased at AVDD/2. Mono Output or Virtual Ground for Capless Headphone. Biased at AVDD/2 when set as mono output. Analog Ground. The AGND and DGND pins can be tied together on a common ground plane. AGND should be decoupled locally to AVDD with a 100 nF capacitor. 1.8 V to 3.3 V Analog Supply for ADC, Output Driver, and Input to Digital Supply Regulator. This pin should be decoupled locally to AGND with a 100 nF capacitor. Digital Core Supply Decoupling Point. The digital supply is generated from an on-board regulator and does not require an external supply. DVDDOUT should be decoupled to DGND with a 100 nF capacitor and a 10 μF capacitor. Digital Ground. The AGND and DGND pins can be tied together on a common ground plane. DGND should be decoupled to DVDDOUT and to IOVDD with 100 nF capacitors and 10 μF capacitors. ADC Serial Output Data (ADC_SDATA). General-Purpose Input/Output 1 (GPIO1). DAC Serial Input Data (DAC_SDATA). General-Purpose Input/Output 0 (GPIO0). Serial Data Port Bit Clock (BCLK). General-Purpose Input/Output 2 (GPIO2). Serial Data Port Frame Clock (LRCLK). General-Purpose Input/Output 3 (GPIO3). I2C Address Bit 1 (ADDR1). SPI Data Input (CDATA). I2C Data (SDA). This pin is a bidirectional open-collector input/output. The line connected to this pin should have a 2 kΩ pull-up resistor. SPI Data Output (COUT). This pin is used for reading back registers and memory locations. It is three-state when an SPI read is not active. I2C Clock (SCL). This pin is always an open-collector input when in I2C control mode. The line connected to this pin should have a 2 kΩ pull-up resistor. SPI Clock (CCLK). This pin can run continuously or be gated off between SPI transactions. Exposed Pad. The exposed pad is connected internally to the ADAU1761 grounds. For increased reliability of the solder joints and maximum thermal capability, it is recommended that the pad be soldered to the ground plane. See the Exposed Pad PCB Design section for more information. A_IN = analog input, A_OUT = analog output, D_IN = digital input, D_IO = digital input/output, PWR = power. Rev. C | Page 16 of 92 ADAU1761 28 –30 26 –35 24 –40 22 –45 20 –50 –55 16 14 12 10 –65 –70 –75 –80 8 –85 6 –90 4 –95 2 –100 0 –60 –50 –40 –30 –20 –10 0 DIGITAL 1kHz INPUT SIGNAL (dBFS) –105 –60 –50 –40 –30 –20 –10 0 DIGITAL 1kHz INPUT SIGNAL (dBFS) Figure 8. Headphone Amplifier Power vs. Input Level, 16 Ω Load Figure 11. Headphone Amplifier THD + N vs. Input Level, 16 Ω Load 18 0 16 –10 –20 14 –30 12 THD + N (dBV) STEREO OUTPUT POWER (mW) –60 07680-056 THD + N (dBV) 18 07680-055 STEREO OUTPUT POWER (mW) TYPICAL PERFORMANCE CHARACTERISTICS 10 8 6 –40 –50 –60 –70 –80 4 –90 2 –40 –30 –20 –10 0 DIGITAL 1kHz INPUT SIGNAL (dBFS) –60 –50 –40 –30 –20 –10 07680-058 –50 07680-057 –100 0 –60 0 DIGITAL 1kHz INPUT SIGNAL (dBFS) Figure 9. Headphone Amplifier Power vs. Input Level, 32 Ω Load Figure 12. Headphone Amplifier THD + N vs. Input Level, 32 Ω Load 0 0.04 −10 0.02 −30 MAGNITUDE (dBFS) MAGNITUDE (dBFS) −20 −40 −50 −60 −70 0 –0.02 –0.04 −80 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 FREQUENCY (NORMALIZED TO fS) 0.9 1.0 0 07680-008 −100 Figure 10. ADC Decimation Filter, 64× Oversampling, Normalized to fS 0.05 0.10 0.15 0.20 0.25 0.30 FREQUENCY (NORMALIZED TO fS) 0.35 0.40 07680-009 –0.06 −90 Figure 13. ADC Decimation Filter Pass-Band Ripple, 64× Oversampling, Normalized to fS Rev. C | Page 17 of 92 0.10 –10 0.08 –20 0.06 –30 0.04 –40 –50 –60 –70 0.02 0 –0.02 –0.04 –80 –0.06 –90 –0.08 –100 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 FREQUENCY (NORMALIZED TO fS) –0.10 0 Figure 14. ADC Decimation Filter, 128× Oversampling, Normalized to fS 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 FREQUENCY (NORMALIZED TO fS) 07680-011 MAGNITUDE (dBFS) 0 07680-010 MAGNITUDE (dBFS) ADAU1761 Figure 17. ADC Decimation Filter Pass-Band Ripple, 128× Oversampling, Normalized to fS 0 0.04 –10 0.02 –30 MAGNITUDE (dBFS) MAGNITUDE (dBFS) –20 –40 –50 –60 –70 0 −0.02 −0.04 –80 –90 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 FREQUENCY (NORMALIZED TO fS) 0 Figure 15. ADC Decimation Filter, 128× Oversampling, Double-Rate Mode, Normalized to fS 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 FREQUENCY (NORMALIZED TO fS) 07680-013 0 07680-012 –100 −0.06 Figure 18. ADC Decimation Filter Pass-Band Ripple, 128× Oversampling, Double-Rate Mode, Normalized to fS 0 0.20 −10 0.15 0.10 −30 MAGNITUDE (dBFS) −40 −50 −60 −70 0 –0.05 –0.10 −80 –0.15 −90 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 FREQUENCY (NORMALIZED TO fS) 0.9 1.0 –0.20 07680-014 −100 0.05 Figure 16. DAC Interpolation Filter, 64× Oversampling, Double-Rate Mode, Normalized to fS 0 0.05 0.10 0.15 0.20 0.25 0.30 FREQUENCY (NORMALIZED TO fS) 0.35 0.40 07680-015 MAGNITUDE (dBFS) −20 Figure 19. DAC Interpolation Filter Pass-Band Ripple, 64× Oversampling, Double-Rate Mode, Normalized to fS Rev. C | Page 18 of 92 0.05 –10 0.04 –20 0.03 –30 0.02 –40 –50 –60 –70 0.01 0 –0.01 –0.02 –80 –0.03 –90 –0.04 –100 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 FREQUENCY (NORMALIZED TO fS) –0.05 Figure 20. DAC Interpolation Filter, 128× Oversampling, Normalized to fS 0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 FREQUENCY (NORMALIZED TO fS) 07680-017 MAGNITUDE (dBFS) 0 07680-016 MAGNITUDE (dBFS) ADAU1761 Figure 23. DAC Interpolation Filter Pass-Band Ripple, 128× Oversampling, Normalized to fS 0 0.20 −10 0.15 0.10 −30 MAGNITUDE (dBFS) −40 −50 −60 −70 0 –0.05 –0.10 −80 –0.15 −90 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 FREQUENCY (NORMALIZED TO fS) –0.20 07680-018 −100 0.05 Figure 21. DAC Interpolation Filter, 128× Oversampling, Double-Rate Mode, Normalized to fS 0 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 FREQUENCY (NORMALIZED TO fS) Figure 24. DAC Interpolation Filter Pass-Band Ripple, 128× Oversampling, Double-Rate Mode, Normalized to fS 12 90 11 80 10 70 IMPEDANCE (kΩ) 8 7 6 5 4 3 60 50 40 30 20 2 10 100 200 300 400 500 600 700 800 900 1000 1100 INSTRUCTIONS 0 GAIN (dB) Figure 22. Typical DSP Current Draw Figure 25. Input Impedance vs. Gain for Analog Inputs Rev. C | Page 19 of 92 07680-125 0 35.00 32.75 30.50 28.25 26.00 23.75 21.50 19.25 17.00 14.75 12.50 10.25 8.00 5.75 3.50 1.25 –1.00 –3.25 –5.50 –7.75 –10.00 –12.25 1 07680-065 CURRENT (mA) 9 0 07680-019 MAGNITUDE (dBFS) −20 ADAU1761 SYSTEM BLOCK DIAGRAMS FROM VOLTAGE REGULATOR (1.8V TO 3.3V) 10µF + 0.1µF 10µF 10µF + + 0.1µF 0.1µF 0.1µF 1.2nH THE INPUT CAPACITOR VALUE DEPENDS ON THE INPUT IMPEDANCE, WHICH VARIES WITH THE VOLUME SETTING. DVDDOUT IOVDD AVDD 9.1pF AVDD 10µF LOUTP LINP LEFT MICROPHONE EARPIECE SPEAKER LOUTN LINN 10µF RHP CAPLESS HEADPHONE OUTPUT MONOOUT 2kΩ LHP ROUTP ADAU1761 MICBIAS EARPIECE SPEAKER ROUTN 2kΩ 10µF RINN RIGHT MICROPHONE RINP 10µF ADC_SDATA/GPIO1 JACK DETECTION SIGNAL JACKDET/MICIN DAC_SDATA/GPIO0 SERIAL DATA LRCLK/GPIO3 AUX LEFT 1kΩ BCLK/GPIO2 10µF LAUX ADDR1/CDATA 10µF RAUX SDA/COUT SYSTEM CONTROLLER SCL/CCLK 1kΩ AGND CM 0.1µF 10µF + 07680-045 CLOCK SOURCE ADDR0/CLATCH MCLK AGND 49.9Ω DGND AUX RIGHT Figure 26. System Block Diagram Rev. C | Page 20 of 92 ADAU1761 FROM VOLTAGE REGULATOR (1.8V TO 3.3V) 10µF + 0.1µF 10µF 10µF + + 0.1µF 0.1µF 0.1µF 1.2nH THE INPUT CAPACITOR VALUE DEPENDS ON THE INPUT IMPEDANCE, WHICH VARIES WITH THE VOLUME SETTING. DVDDOUT IOVDD AVDD 9.1pF AVDD MICBIAS LOUTP VDD 10µF SINGLE-ENDED ANALOG OUTPUT MICROPHONE EARPIECE SPEAKER LOUTN LINN RHP CM CAPLESS HEADPHONE OUTPUT MONOOUT LINP GND LHP ADAU1761 ROUTP EARPIECE SPEAKER ROUTN VDD 10µF SINGLE-ENDED ANALOG OUTPUT MICROPHONE RINN CM RINP GND ADC_SDATA/GPIO1 JACK DETECTION SIGNAL JACKDET/MICIN DAC_SDATA/GPIO0 SERIAL DATA LRCLK/GPIO3 AUX LEFT 1kΩ BCLK/GPIO2 10µF LAUX ADDR1/CDATA 10µF RAUX SDA/COUT SYSTEM CONTROLLER SCL/CCLK 1kΩ AGND CM 0.1µF 10µF + 07680-059 CLOCK SOURCE ADDR0/CLATCH MCLK AGND 49.9Ω DGND AUX RIGHT Figure 27. System Block Diagram with Analog Microphones Rev. C | Page 21 of 92 ADAU1761 FROM VOLTAGE REGULATOR (1.8V TO 3.3V) 10µF + 0.1µF 10µF 10µF + + 0.1µF 0.1µF 0.1µF 1.2nH DVDDOUT IOVDD AVDD MICBIAS RHP CM LHP LINP 10µF LINN DIGITAL DATA MICROPHONE L/R SELECT 2.5V TO 5.0V MONOOUT CLK 0.1µF CAPLESS HEADPHONE OUTPUT AVDD BCLK VDD 9.1pF RINN GND RINP 22nF LOUTP ADAU1761 22nF LOUTN BCLK CLK 22nF REXT L/R SELECT VDD VDD INL+ INL– SSM2306 OUTL+ OUTL– CLASS-D 2W STEREO SPEAKER DRIVER INR+ OUTR+ OUTR– INR– SD GND LEFT SPEAKER RIGHT SPEAKER GND GND JACKDET/MICIN AUX LEFT 1kΩ DAC_SDATA/GPIO0 10µF LAUX SERIAL DATA LRCLK/GPIO3 SHUTDOWN ADC_SDATA/GPIO1 BCLK/GPIO2 10µF RAUX ADDR1/CDATA SDA/COUT SYSTEM CONTROLLER 1kΩ SCL/CCLK CLOCK SOURCE MCLK ADDR0/CLATCH AGND 49.9Ω AGND CM 0.1µF 10µF + 07680-060 AUX RIGHT DGND 0.1µF REXT REXT ROUTN DIGITAL DATA MICROPHONE REXT 22nF ROUTP VDD 0.1µF Figure 28. System Block Diagram with Digital Microphones and SSM2306 Class-D Speaker Driver Rev. C | Page 22 of 92 ADAU1761 THEORY OF OPERATION The ADAU1761 is a low power audio codec with an integrated stream-oriented DSP core, making it an all-in-one package that offers high quality audio, low power, small size, and many advanced features. The stereo ADC and stereo DAC each have an SNR of at least +98 dB and a THD + N of at least −90 dB. The serial data port is compatible with I2S, left-justified, rightjustified, and TDM modes for interfacing to digital audio data. The operating voltage range is 1.8 V to 3.65 V, with an on-board regulator generating the internal digital supply voltage. The record signal path includes very flexible input configurations that can accept differential and single-ended analog microphone inputs as well as a digital microphone input. A microphone bias pin provides seamless interfacing to electret microphones. Input configurations can accept up to six single-ended analog signals or variations of stereo differential or stereo single-ended signals with two additional auxiliary single-ended inputs. Each input signal has its own programmable gain amplifier (PGA) for volume adjustment and can be routed directly to the playback path output mixers, bypassing the ADCs. An automatic level control (ALC) can also be implemented to keep the recording volume constant. The ADCs and DACs are high quality, 24-bit Σ-Δ converters that operate at selectable 64× or 128× oversampling ratios. The base sampling rate of the converters is set by the input clock rate and can be further scaled with the converter control register settings. The converters can operate at sampling frequencies from 8 kHz to 96 kHz. The ADCs and DACs also include very fine-step digital volume controls. The playback path allows input signals and DAC outputs to be mixed into various output configurations. Headphone drivers are available for a stereo headphone output, and the other output pins are capable of differentially driving an earpiece speaker. Capless headphone outputs are possible with the use of the mono output as a virtual ground connection. The stereo line outputs can be used as either single-ended or differential outputs and as an optional mix-down mono output. The DSP core introduces many features that make this codec unique and optimized for audio processing. The program and parameter RAMs can be loaded with custom audio processing signal flow built using the SigmaStudio graphical programming software from Analog Devices, Inc. The values stored in the parameter RAM control individual signal processing blocks, such as equalization filters, dynamics processors, audio delays, and mixer levels. The SigmaStudio software is used to program and control the SigmaDSP through the control port. Along with designing and tuning a signal flow, the tools can be used to configure all of the DSP registers. The SigmaStudio graphical interface allows anyone with digital or analog audio processing knowledge to easily design DSP signal flow and port it to a target application. At the same time, it provides enough flexibility and programmability for an experienced DSP programmer to have in-depth control of the design. In SigmaStudio, the user can connect graphical blocks (such as biquad filters, dynamics processors, mixers, and delays), compile the design, and load the program and parameter files into the ADAU1761 memory through the control port. Signal processing blocks available in the provided libraries include the following: • • • • • • • • • • • • • Enhanced stereo capture Single- and double-precision biquad filters FIR filters Dynamics processors with peak or rms detection for mono and multichannel dynamics Mixers and splitters Tone and noise generators Fixed and variable gain Loudness Delay Stereo enhancement Dynamic bass boost Noise and tone sources Level detectors Additional processing blocks are always being developed. Analog Devices also provides proprietary and third-party algorithms for applications such as matrix decoding, bass enhancement, and surround virtualizers. Contact Analog Devices (www.analog.com) for information about licensing these algorithms. The ADAU1761 can generate its internal clocks from a wide range of input clocks by using the on-board fractional PLL. The PLL accepts inputs from 8 MHz to 27 MHz. The ADAU1761 is provided in a small, 32-lead, 5 mm × 5 mm LFCSP with an exposed bottom pad. Rev. C | Page 23 of 92 ADAU1761 STARTUP, INITIALIZATION, AND POWER This section describes the procedure for properly starting up the ADAU1761. The following sequence provides a high level approach to the proper initiation of the system. 1. 2. 3. 4. POWER REDUCTION MODES Sections of the ADAU1761 chip can be turned on and off as needed to reduce power consumption. These include the ADCs, the DACs, the PLL, and the DSP core. Apply power to the ADAU1761. Lock the PLL to the input clock (if using the PLL). Enable the core clock. Load the register settings. In addition, the control registers can be used to configure some functions for power saving, normal, or enhanced performance operation. See the Control Registers section for more information. See the Startup section for more information about the proper start-up sequence. The digital filters of the ADCs and DACs can each be set to oversampling ratios of 64× or 128× (default). Setting the oversampling ratios to 64× for these filters lowers power consumption with a minimal impact on performance. See the Digital Filters section for specifications; see the Typical Performance Characteristics section for graphs of these filters. POWER-UP SEQUENCE The ADAU1761 uses a power-on reset (POR) circuit to reset the registers upon power-up. The POR monitors the DVDDOUT pin and generates a reset signal whenever power is applied to the chip. During the reset, the ADAU1761 is set to the default values documented in the register map (see the Control Registers section). Typically, with a 10 μF capacitor on AVDD, the POR takes approximately 14 ms. DIGITAL POWER SUPPLY The digital power supply for the ADAU1761 is generated from an internal regulator. This regulator generates a 1.5 V supply internally. The only external connection to this regulator is the DVDDOUT bypassing point. A 100 nF capacitor and a 10 μF capacitor should be connected between this pin and DGND. 1.5V 1.35V DVDDOUT 0.95V INPUT/OUTPUT POWER SUPPLY AVDD POR ACTIVE POR FINISHED 07680-061 PART READY POR POR ACTIVE Figure 29. Power-On Reset Sequence The PLL lock time is dependent on the MCLK rate. Typical lock times are provided in Table 11. The DSP can be enabled immediately after the PLL is locked. Table 11. PLL Lock Times PLL Mode Fractional Fractional Integer Fractional Fractional Fractional Fractional Fractional Fractional Integer Fractional Fractional MCLK Frequency 8 MHz 12 MHz 12.288 MHz 13 MHz 14.4 MHz 19.2 MHz 19.68 MHz 19.8 MHz 24 MHz 24.576 MHz 26 MHz 27 MHz Lock Time (Typical) 3.5 ms 3.0 ms 2.96 ms 2.4 ms 2.4 ms 2.98 ms 2.98 ms 2.98 ms 2.95 ms 2.96 ms 2.4 ms 2.4 ms The power for the digital output pins is supplied from IOVDD, and this pin also sets the highest input voltage that should be seen on the digital input pins. IOVDD should be set between 1.8 V and 3.3 V; no digital input signal should be at a voltage level higher than the one on IOVDD. The current draw of this pin is variable because it depends on the loads of the digital outputs. IOVDD should be decoupled to DGND with a 100 nF capacitor and a 10 μF capacitor. CLOCK GENERATION AND MANAGEMENT The ADAU1761 uses a flexible clocking scheme that enables the use of many different input clock rates. The PLL can be bypassed or used, resulting in two different approaches to clock management. For more information about clocking schemes, PLL configuration, and sampling rates, see the Clocking and Sampling Rates section. Case 1: PLL Is Bypassed If the PLL is bypassed, the core clock is derived directly from the MCLK input. The rate of this clock must be set properly in Register R0 (clock control register, Address 0x4000) using the INFREQ[1:0] bits. When the PLL is bypassed, supported external clock rates are 256 × fS, 512 × fS, 768 × fS, and 1024 × fS, where fS is the base sampling rate. The core clock of the chip is off until the core clock enable bit (COREN) is asserted. If a clock slower than 1024 × fS is directly input to the ADAU1761 (bypassing the PLL), the number of available SigmaDSP processing cycles is reduced and the DSPSR bits in Register R57 (Address 0x40EB) should be adjusted accordingly. Rev. C | Page 24 of 92 ADAU1761 Case 2: PLL Is Used The core clock to the entire chip is off during the PLL lock acquisition period. The user can poll the lock bit to determine when the PLL has locked. After lock is acquired, the ADAU1761 can be started by asserting the core clock enable bit (COREN) in Register R0 (clock control register, Address 0x4000). This bit enables the core clock to all the internal blocks of the ADAU1761. To program the PLL during initialization or reconfiguration of the clock setting, the following procedure must be followed: 1. 2. 3. 4. 5. PLL Lock Acquisition During the lock acquisition period, only Register R0 (Address 0x4000) and Register R1 (Address 0x4002) are accessible through the control port. Because all other registers require a valid master clock for reading and writing, do not attempt to access any other register. Any read or write is prohibited until the core clock enable bit (COREN) and the lock bit are both asserted. Power down the PLL. Reset the PLL control register. Start the PLL. Poll the lock bit. Assert the core clock enable bit after the PLL lock is acquired. The PLL control register (Register R1, Address 0x4002) is a 48-bit register where all bits must be written with a single continuous write to the control port. Rev. C | Page 25 of 92 ADAU1761 CLOCKING AND SAMPLING RATES R57: DSP SAMPLING RATE SETTING DSPSR[3:0] fS/0.5, 1, 1.5, 2, 3, 4, 6 R1: PLL CONTROL REGISTER MCLK ÷X R0: CLOCK CONTROL REGISTER × (R + N/M) CLKSRC INFREQ[1:0] 256 × fS, 512 × fS, 768 × fS, 1024 × fS ADCs R17: CONVERTER SAMPLING RATE CORE CLOCK DACs CONVSR[2:0] fS/0.5, 1, 1.5, 2, 3, 4, 6 R64: SERIAL PORT SAMPLING RATE ADC_SDATA/GPIO1 BCLK/GPIO2 LRCLK/GPIO3 DAC_SDATA/GPIO0 SERIAL DATA INPUT/ OUTPUT PORT 07680-020 SPSR[2:0] fS/0.5, 1, 1.5, 2, 3, 4, 6 Figure 30. Clock Tree Diagram CORE CLOCK Clocks for the converters, the serial ports, and the DSP are derived from the core clock. The core clock can be derived directly from MCLK or it can be generated by the PLL. The CLKSRC bit (Bit 3 in Register R0, Address 0x4000) determines the clock source. To utilize the maximum amount of DSP instructions, the core clock should run at a rate of 1024 × fS. Table 12. Clock Control Register (Register R0, Address 0x4000) Bits 3 Bit Name CLKSRC The INFREQ[1:0] bits should be set according to the expected input clock rate selected by CLKSRC; this value also determines the core clock rate and the base sampling frequency, fS. [2:1] INFREQ[1:0] For example, if the input to CLKSRC = 49.152 MHz (from PLL), then 0 COREN INFREQ[1:0] = 1024 × fS fS = 49.152 MHz/1024 = 48 kHz The PLL output clock rate is always 1024 × fS, and the clock control register automatically sets the INFREQ[1:0] bits to 1024 × fS when using the PLL. When using a direct clock, the INFREQ[1:0] frequency should be set according to the MCLK pin clock rate and the desired base sampling frequency. Rev. C | Page 26 of 92 Settings 0: Direct from MCLK pin (default) 1: PLL clock 00: 256 × fS (default) 01: 512 × fS 10: 768 × fS 11: 1024 × fS 0: Core clock disabled (default) 1: Core clock enabled ADAU1761 SAMPLING RATES PLL The ADCs, DACs, and serial port share a common sampling rate that is set in Register R17 (Converter Control 0 register, Address 0x4017). The CONVSR[2:0] bits set the sampling rate as a ratio of the base sampling frequency. The DSP sampling rate is set in Register R57 (DSP sampling rate setting register, Address 0x40EB) using the DSPSR[3:0] bits, and the serial port sampling rate is set in Register R64 (serial port sampling rate register, Address 0x40F8) using the SPSR[2:0] bits. The PLL uses the MCLK as a reference to generate the core clock. PLL settings are set in Register R1 (PLL control register, Address 0x4002). Depending on the MCLK frequency, the PLL must be set for either integer or fractional mode. The PLL can accept input frequencies in the range of 8 MHz to 27 MHz. Table 13. 48 kHz Base Sampling Rate Divisions Base Sampling Frequency fS = 48 kHz Sampling Rate Scaling fS/1 fS/6 fS/4 fS/3 fS/2 fS/1.5 fS/0.5 ÷X MCLK × (R + N/M) TO PLL CLOCK DIVIDER 07680-021 It is recommended that the sampling rates for the converters, serial ports, and DSP be set to the same value, unless appropriate compensation filtering is done within the DSP. Table 13 and Table 14 list the sampling rate divisions for common base sampling rates. All six bytes in the PLL control register must be written with a single continuous write to the control port. Figure 31. PLL Block Diagram Integer Mode Integer mode is used when the MCLK is an integer (R) multiple of the PLL output (1024 × fS). For example, if MCLK = 12.288 MHz and fS = 48 kHz, then Sampling Rate 48 kHz 8 kHz 12 kHz 16 kHz 24 kHz 32 kHz 96 kHz PLL required output = 1024 × 48 kHz = 49.152 MHz R = 49.152 MHz/12.288 MHz = 4 In integer mode, the values set for N and M are ignored. Fractional Mode Fractional mode is used when the MCLK is a fractional (R + (N/M)) multiple of the PLL output. For example, if MCLK = 12 MHz and fS = 48 kHz, then Table 14. 44.1 kHz Base Sampling Rate Divisions PLL required output = 1024 × 48 kHz = 49.152 MHz Base Sampling Frequency fS = 44.1 kHz R + (N/M) = 49.152 MHz/12 MHz = 4 + (12/125) Sampling Rate Scaling fS/1 fS/6 fS/4 fS/3 fS/2 fS/1.5 fS/0.5 Sampling Rate 44.1 kHz 7.35 kHz 11.025 kHz 14.7 kHz 22.05 kHz 29.4 kHz 88.2 kHz Common fractional PLL parameter settings for 44.1 kHz and 48 kHz sampling rates can be found in Table 16 and Table 17. The PLL outputs a clock in the range of 41 MHz to 54 MHz, which should be taken into account when calculating PLL values and MCLK frequencies. Table 15. PLL Control Register (Register R1, Address 0x4002) Bits [47:32] Bit Name M[15:0] [31:16] N[15:0] [14:11] R[3:0] Description Denominator of the fractional PLL: 16-bit binary number 0x00FD: M = 253 (default) Numerator of the fractional PLL: 16-bit binary number 0x000C: N = 12 (default) Integer part of PLL: four bits, only values 2 to 8 are valid 0010: R = 2 (default) 0011: R = 3 0100: R = 4 0101: R = 5 0110: R = 6 0111: R = 7 1000: R = 8 Rev. C | Page 27 of 92 ADAU1761 Bits [10:9] Bit Name X[1:0] 8 Type 1 Lock 0 PLLEN Description PLL input clock divider 00: X = 1 (default) 01: X = 2 10: X = 3 11: X = 4 PLL operation mode 0: Integer (default) 1: Fractional PLL lock (read-only bit) 0: PLL unlocked (default) 1: PLL locked PLL enable 0: PLL disabled (default) 1: PLL enabled Table 16. Fractional PLL Parameter Settings for fS = 44.1 kHz (PLL Output = 45.1584 MHz = 1024 × fS) MCLK Input (MHz) 8 12 13 14.4 19.2 19.68 19.8 24 26 27 Input Divider (X) 1 1 1 2 2 2 2 2 2 2 Integer (R) 5 3 3 6 4 4 4 3 3 3 Denominator (M) 625 625 8125 125 125 1025 1375 625 8125 1875 Numerator (N) 403 477 3849 34 88 604 772 477 3849 647 R2: PLL Control Setting (Hex) 0x0271 0193 2901 0x0271 01DD 1901 0x1FBD 0F09 1901 0x007D 0022 3301 0x007D 0058 2301 0x0401 025C 2301 0x055F 0304 2301 0x0271 01DD 1B01 0x1FBD 0F09 1B01 0x0753 0287 1B01 Table 17. Fractional PLL Parameter Settings for fS = 48 kHz (PLL Output = 49.152 MHz = 1024 × fS) MCLK Input (MHz) 8 12 13 14.4 19.2 19.68 19.8 24 26 27 Input Divider (X) 1 1 1 2 2 2 2 2 2 2 Integer (R) 6 4 3 6 5 4 4 4 3 3 Denominator (M) 125 125 1625 75 25 205 825 125 1625 1125 Numerator (N) 18 12 1269 62 3 204 796 12 1269 721 R2: PLL Control Setting (Hex) 0x007D 0012 3101 0x007D 000C 2101 0x0659 04F5 1901 0x004B 003E 3301 0x0019 0003 2B01 0x00CD 00CC 2301 0x0339 031C 2301 0x007D 000C 2301 0x0659 04F5 1B01 0x0465 02D1 1B01 Table 18. Integer PLL Parameter Settings for fS = 48 kHz (PLL Output = 49.152 MHz = 1024 × fS) MCLK Input (MHz) 12.288 24.576 1 Input Divider (X) 1 1 Integer (R) 4 2 Denominator (M) Don’t care Don’t care X = don’t care. Rev. C | Page 28 of 92 Numerator (N) Don’t care Don’t care R2: PLL Control Setting (Hex) 1 0xXXXX XXXX 2001 0xXXXX XXXX 1001 ADAU1761 RECORD SIGNAL PATH MICIN LEFT DIGITAL MICROPHONE INTERFACE JACKDET/MICIN MICIN RIGHT LINNG[2:0] MIXER 1 (LEFT RECORD MIXER) –12dB TO +6dB PGA LDBOOST[1:0] LINN –12dB TO +35.25dB LINP LEFT ADC MUTE/0dB/20dB LINPG[2:0] –12dB TO +6dB MIXER 1 OUTPUT (TO PLAYBACK MIXER) ALCSEL[2:0] LDVOL[5:0] INSEL ALC CONTROL DECIMATOR/ ALC/ DIGITAL VOLUME MX1AUXG[2:0] LAUX –12dB TO +6dB AUXILIARY BYPASS MX2AUXG[2:0] RAUX –12dB TO +6dB MIXER 2 OUTPUT (TO PLAYBACK MIXER) RINPG[2:0] –12dB TO +6dB PGA RDBOOST[1:0] RINP –12dB TO +35.25dB RINN RIGHT ADC MUTE/0dB/20dB MIXER 2 (RIGHT RECORD MIXER) RINNG[2:0] INSEL –12dB TO +6dB RDVOL[5:0] 07680-022 ALCSEL[2:0] ALC CONTROL Figure 32. Record Signal Path INPUT SIGNAL PATHS The ADAU1761 can accept both line level and microphone inputs. The analog inputs can be configured in a single-ended or differential configuration. There is also an input for a digital microphone. The analog inputs are biased at AVDD/2. Unused input pins should be connected to CM. Each of the six analog inputs has individual gain controls (boost or cut). The input signals are mixed and routed to an ADC. The mixed input signals can also bypass the ADCs and be routed directly to the playback mixers. Left channel inputs are mixed before the left ADC; however, it is possible to route the mixed analog signal around the ADC and output it into a left or right output channel. The same capabilities apply to the right channel and the right ADC. Signals are inverted through the PGAs and the mixers. The result of this inversion is that differential signals input through the PGA are output from the ADCs at the same polarity as they are input. Single-ended inputs that pass through the mixer but not through the PGA are inverted. The ADCs are noninverting. The input impedance of the analog inputs varies with the gain of the PGA. This impedance ranges from 1.7 kΩ at the 35.25 dB gain setting to 80.4 kΩ at the −12 dB setting. This range is shown in Figure 25. Rev. C | Page 29 of 92 ADAU1761 Analog Microphone Inputs Analog Line Inputs For microphone inputs, configure the part in either stereo pseudo-differential mode or stereo full differential mode. Line input signals can be accepted by any analog input. It is possible to route signals on the RINN, RINP, LINN, and LINP pins around the differential amplifier to their own amplifier and to use these pins as single-ended line inputs by disabling the LDEN and RDEN bits (Bit 0 in Register R8, Address 0x400E, and Bit 0 in Register R9, Address 0x400F). Figure 35 depicts a stereo single-ended line input using the RINN and LINN pins. The LINN and LINP pins are the inverting and noninverting inputs for the left channel, respectively. The RINN and RINP pins are the inverting and noninverting inputs for the right channel, respectively. For a differential microphone input, connect the positive signal to the noninverting input of the PGA and the negative signal to the inverting input of the PGA, as shown in Figure 33. The PGA settings are controlled with Register R8 (left differential input volume control register, Address 0x400E) and Register R9 (right differential input volume control register, Address 0x400F). The PGA must first be enabled by setting the RDEN and LDEN bits. The LAUX and RAUX pins are single-ended line inputs. They can be used together as a stereo single-ended auxiliary input, as shown in Figure 35. These inputs can bypass the input gain control, mixers, and ADCs to directly connect to the output playback mixers (see auxiliary bypass in Figure 32). ADAU1761 LINNG[2:0] ADAU1761 LINP LEFT PGA LEFT LINE INPUT LDBOOST[1:0] LINN –12dB TO +6dB LEFT MICROPHONE LINN MUTE/ 0dB/20dB –12dB TO +35.25dB 2kΩ LEFT AUX INPUT RIGHT AUX INPUT MICBIAS LAUX RAUX AUXILIARY BYPASS RINNG[2:0] RINN RDBOOST[1:0] –12dB TO +6dB RIGHT MICROPHONE RINP MUTE/ 0dB/20dB Figure 35. Stereo Single-Ended Line Input with Stereo Auxiliary Bypass 07680-052 –12dB TO +35.25dB Figure 33. Stereo Differential Microphone Configuration The PGA can also be used for single-ended microphone inputs. Connect LINP and/or RINP to the CM pin. In this configuration, the signal connects to the inverting input of the PGA, LINN and/or RINN, as shown in Figure 34. ADAU1761 LINN LEFT MICROPHONE 2kΩ LEFT PGA LDBOOST[1:0] LINP CM –12dB TO +35.25dB MUTE/ 0dB/20dB MICBIAS RIGHT PGA 2kΩ RINP RDBOOST[1:0] RINN –12dB TO +35.25dB MUTE/ 0dB/20dB 07680-053 RIGHT MICROPHONE RINN 07680-054 RIGHT PGA 2kΩ RIGHT LINE INPUT Figure 34. Stereo Single-Ended Microphone Configuration Rev. C | Page 30 of 92 ADAU1761 Digital Microphone Input Microphone Bias When using a digital microphone connected to the JACKDET/ MICIN pin, the JDFUNC[1:0] bits in Register R2 (Address 0x4008) must be set to 10 to enable the microphone input and disable the jack detection function. The ADAU1761 must operate in master mode and source BCLK to the input clock of the digital microphone. The DSPRUN bit must also be asserted in Register R62 (DSP run register, Address 0x40F6) for digital microphone operation. The MICBIAS pin provides a voltage reference for electret analog microphones. The MICBIAS voltage is set in Register R10 (record microphone bias control register, Address 0x4010). In this register, the MICBIAS output can be enabled or disabled. Additional options include high performance operation and a gain boost. The gain boost provides two different voltage biases: 0.65 × AVDD or 0.90 × AVDD. When enabled, the high performance bit increases supply current to the microphone bias circuit to decrease rms input noise. The digital microphone signal bypasses record path mixers and ADCs and is routed directly into the decimation filters. The digital microphone and ADCs share decimation filters and, therefore, both cannot be used simultaneously. The digital microphone input select bit, INSEL, can be set in Register R19 (ADC control register, Address 0x4019). Figure 36 depicts the digital microphone interface and signal routing. JACKDET/MICIN R2: DIGITAL MICROPHONE/ JACK DETECTION CONTROL JDFUNC[1:0] DIGITAL MICROPHONE INTERFACE LEFT CHANNEL ANALOG-TO-DIGITAL CONVERTERS The ADAU1761 uses two 24-bit Σ-Δ analog-to-digital converters (ADCs) with selectable oversampling ratios of 64× or 128× (selected by Bit 3 in Register R17, Address 0x4017). ADC Full-Scale Level The full-scale input to the ADCs (0 dBFS) depends on AVDD. At AVDD = 3.3 V, the full-scale input level is 1.0 V rms. This full-scale analog input will output a digital signal at −1.38 dBFS. This gain offset is built into the ADAU1761 to prevent clipping. The full-scale input level scales linearly with the level of AVDD. TO JACK DETECTION CIRCUIT RIGHT ADC The MICBIAS pin can also be used to cleanly supply voltage to digital microphones or analog microphones with separate power supply pins. RIGHT CHANNEL For single-ended and pseudo-differential signals, the full-scale value corresponds to the signal level at the pins, 0 dBFS. LEFT ADC The full differential full-scale input level is measured after the differential amplifier, which corresponds to −6 dBFS at each pin. R19: ADC CONTROL INSEL DECIMATORS Figure 36. Digital Microphone Interface Block Diagram 07680-023 Signal levels above the full-scale value cause the ADCs to clip. Digital ADC Volume Control The digital ADC volume can be attenuated before DSP processing using Register R20 (left input digital volume register, Address 0x401A) and Register R21 (right input digital volume register, Address 0x401B). High-Pass Filter By default, a high-pass filter is used in the ADC path to remove dc offsets; this filter can be enabled or disabled in Register R19 (ADC control register, Address 0x4019). At fS = 48 kHz, the corner frequency of this high-pass filter is 2 Hz. Rev. C | Page 31 of 92 ADAU1761 AUTOMATIC LEVEL CONTROL (ALC) • The ADAU1761 contains a hardware automatic level control (ALC). The ALC is designed to continuously adjust the PGA gain to keep the recording volume constant as the input level varies. For optimal noise performance, the ALC uses the analog PGA to adjust the gain instead of using a digital method. This ensures that the ADC noise is not amplified at low signal levels. Extremely small gain step sizes are used to ensure high audio quality during gain changes. To use the ALC function, the inputs must be applied either differentially or pseudo-differentially to input pins LINN and LINP, for the left channel, and RINN and RINP, for the right channel. The ALC function is not available for the auxiliary line input pins, LAUX and RAUX. • A block diagram of the ALC block is shown in Figure 37. The ALC logic receives the ADC output signals and analyzes these digital signals to set the PGA gain. The ALC control registers are used to control the time constants and output levels, as described in this section. ANALOG INPUT RIGHT I2 C CONTROL PGA –12dB TO +35.25dB 0.75dB STEP SIZE LEFT ADC MUTE SERIAL PORTS RIGHT ADC ALC DIGITAL 07680-024 ANALOG INPUT LEFT • • Figure 37. ALC Architecture ALC PARAMETERS The ALC function is controlled with the ALC control registers (Address 0x4011 through Address 0x4014) using the following parameters: • • ALCSEL[2:0]: The ALC select bits are used to enable the ALC and set the mode to left only, right only, stereo, or DSP. In stereo mode, the greater of the left or right inputs is used to calculate the gain, and the same gain is then applied to both the left and right channels. In DSP mode, the PGA gain is controlled by the SigmaDSP core. ALCTARG[3:0]: The ALC target is the desired input recording level that the ALC attempts to achieve. ALCATCK[3:0]: The ALC attack time sets how fast the ALC starts attenuating after a sudden increase in input level above the ALC target. Although it may seem that the attack time should be set as fast as possible to avoid clipping on transients, using a moderate value results in better overall sound quality. If the value is too fast, the ALC overreacts to very short transients, causing audible gain-pumping effects, which sounds worse than using a moderate value that allows brief periods of clipping on transients. A typical setting for music recording is 384 ms. A typical setting for voice recording is 24 ms. ALCHOLD[3:0]: These bits set the ALC hold time. When the output signal falls below the target output level, the gain is not increased unless the output remains below the target level for the period of time set by the hold time bits. The hold time is used to prevent the gain from modulating on a steady low frequency sine wave signal, which would cause distortion. ALCDEC[3:0]: The ALC decay time sets how fast the ALC increases the PGA gain after a sudden decrease in input level below the ALC target. A very slow setting can be used if the main function of the ALC is to set a music recording level. A faster setting can be used if the function of the ALC is to compress the dynamic range of a voice recording. Using a very fast decay time can cause audible artifacts such as noise pumping or distortion. A typical setting for music recording is 24.58 sec. A typical setting for voice recording is 1.54 sec. ALCMAX[2:0]: The maximum ALC gain bits are used to limit the maximum gain that can be programmed into the ALC. This can be used to prevent excessive noise in the recording for small input signals. Note that setting this register to a low value may prevent the ALC from reaching its target output level, but this behavior is often desirable to achieve the best overall sound. Figure 38 shows the dynamic behavior of the PGA gain for a tone-burst input. The target output is achieved for three different input levels, with the effect of attack, hold, and decay shown in the figure. Note that for very small signals, the maximum PGA gain may prevent the ALC from achieving its target level; in the same way, for very large inputs, the minimum PGA gain may prevent the ALC from achieving its target level (assuming that the target output level is set to a very low value). The effects of the PGA gain limit are shown in the input/output graph of Figure 39. Rev. C | Page 32 of 92 ADAU1761 the threshold for 250 ms before the noise gate operates. Hysteresis is used so that the threshold for coming out of the mute state is 6 dB higher than the threshold for going into the mute state. There are four operating modes for the noise gate. INPUT Noise Gate Mode 0 (see Figure 40) is selected by setting the NGTYP[1:0] bits to 00. In this mode, the current state of the PGA gain is held at its current state when the noise gate logic is activated. This prevents a large increase in background noise during periods of silence. When using this mode, it is advisable to use a relatively slow decay time. This is because the noise gate takes at least 250 ms to activate, and if the PGA gain has already increased to a large value during this time, the value at which the gain is held will be large. GAIN OUTPUT THRESHOLD HOLD DECAY TIME TIME 07680-025 INPUT ATTACK TIME Figure 38. Basic ALC Operation ANALOG GAIN MAX GAIN = 30dB 250ms MIN PGA GAIN POINT DIGITAL MUTE TARGET 07680-026 INPUT LEVEL (dB) OUTPUT 07680-027 OUTPUT LEVEL (dB) MAX GAIN = 18dB GAIN HELD INTERNAL NOISE GATE ENABLE SIGNAL MAX GAIN = 24dB Figure 39. Effect of Varying the Maximum Gain Parameter NOISE GATE FUNCTION Figure 40. Noise Gate Mode 0 (PGA Gain Hold) • • • NGTYP[1:0]: The noise gate type is set to one of four modes by writing to the NGTYP[1:0] bits. NGEN: The noise gate function is enabled by writing to the NGEN bit. NGTHR[4:0]: The threshold for muting the output is set by writing to the NGTHR[4:0] bits. Noise Gate Mode 1 (see Figure 41) is selected by setting the NGTYP[1:0] bits to 01. In this mode, the ADAU1761 does a simple digital mute of the ADC output. Although this mode completely eliminates any background noise, the effect of an abrupt mute may not be pleasant to the ear. THRESHOLD INPUT ANALOG GAIN 250ms INTERNAL NOISE GATE ENABLE SIGNAL One common problem with noise gate functions is chatter, where a small signal that is close to the noise gate threshold varies in amplitude, causing the noise gate function to open and close rapidly. This causes an unpleasant sound. To reduce this effect, the noise gate in the ADAU1761 uses a combination of a timeout period and hysteresis. The timeout period is set to 250 ms, so the signal must consistently be below Rev. C | Page 33 of 92 DIGITAL MUTE OUTPUT 07680-028 When using the ALC, one potential problem is that for small input signals, the PGA gain can become very large. A side effect of this is that the noise is amplified along with the signal of interest. To avoid this situation, the ADAU1761 noise gate can be used. The noise gate cuts off the ADC output when its signal level is below a set threshold. The noise gate is controlled using the following parameters in the ALC Control 3 register (Address 0x4014): Figure 41. Noise Gate Mode 1 (Digital Mute) ADAU1761 Noise Gate Mode 3 (see Figure 43) is selected by setting the NGTYP[1:0] bits to 11. This mode is the same as Mode 2 except that at the end of the PGA fade gain interval, a digital mute is performed. In general, this mode is the best-sounding mode, because the audible effect of the digital hard mute is reduced by the fact that the gain has already faded to a low level before the mute occurs. Noise Gate Mode 2 (see Figure 42) is selected by setting the NGTYP[1:0] bits to 10. In this mode, the ADAU1761 improves the sound of the noise gate operation by first fading the PGA gain over a period of about 100 ms to the minimum PGA gain value. The ADAU1761 does not do a hard mute after the fade is complete, so some small background noise will still exist. THRESHOLD THRESHOLD INPUT ANALOG GAIN INPUT ANALOG GAIN 250ms MIN GAIN 250ms MIN GAIN 100ms 100ms INTERNAL NOISE GATE ENABLE SIGNAL INTERNAL NOISE GATE ENABLE SIGNAL DIGITAL MUTE DIGITAL MUTE OUTPUT 07680-029 07680-030 OUTPUT Figure 43. Noise Gate Mode 3 (Analog Fade/Digital Mute) Figure 42. Noise Gate Mode 2 (Analog Fade) Rev. C | Page 34 of 92 ADAU1761 PLAYBACK SIGNAL PATH MX3G1[3:0] LEFT INPUT MIXER –15dB TO +6dB MX3G2[3:0] RIGHT INPUT MIXER MIXER 3 (LEFT PLAYBACK MIXER) –15dB TO +6dB MX3AUXG[3:0] LAUX LHPVOL[5:0] –15dB TO +6dB –57dB TO +6dB MIXER 5 (LEFT L/R PLAYBACK MIXER) LEFT DAC LHP LOUTVOL[5:0] MX3LM –57dB TO +6dB LOUTP MX5G3[1:0] RIGHT DAC MX3RM –1 MX6G3[1:0] LOUTN MONOVOL[5:0] MX7[1:0] MIXER 7 (MONO MIXER) MONOOUT –57dB TO +6dB –1 MX4G1[3:0] LEFT INPUT MIXER –15dB TO +6dB MX5G4[1:0] MX4G2[3:0] RIGHT INPUT MIXER MIXER 6 (RIGHT L/R PLAYBACK MIXER) ROUTVOL[5:0] –57dB TO +6dB ROUTP MX6G4[1:0] –15dB TO +6dB RHPVOL[5:0] MX4AUXG[3:0] RAUX ROUTN –15dB TO +6dB –57dB TO +6dB MIXER 4 (RIGHT PLAYBACK MIXER) LEFT DAC RHP 07680-031 MX4LM RIGHT DAC MX4RM Figure 44. Playback Signal Path OUTPUT SIGNAL PATHS Routing Flexibility The outputs of the ADAU1761 can be configured as a variety of differential or single-ended outputs. All analog output pins are capable of driving headphone or earpiece speakers. There are selectable output paths for stereo signals or a downmixed mono output. The line outputs can drive a load of at least 10 kΩ or can be put into HP mode to drive headphones or earpiece speakers. The analog output pins are biased at AVDD/2. The playback path contains five mixers (Mixer 3 to Mixer 7) that perform the following functions: With a 0 dBFS digital input and AVDD = 1.8 V, the full-scale output level is 500 mV rms; when AVDD = 3.3 V, the full-scale output level is 920 mV rms. Signals are inverted through the mixers and volume controls. The result of this inversion is that the polarity of the differential outputs and the headphone outputs is preserved. The singleended mono output is inverted. The DACs are noninverting. • • • Mix signals from the record path and the DACs. Mix or swap the left and right channels. Mix a mono signal or generate a common-mode output. Mixer 3 and Mixer 4 are dedicated to mixing signals from the record path and the DACs. Each of these two mixers can accept signals from the left and right DACs, the left and right input mixers, and the dedicated channel auxiliary input. Signals coming from the record path can be boosted or cut before the playback mixer. For example, the MX4G2[3:0] bits set the gain from the output of Mixer 2 (right record channel) to the input of Mixer 4, hence the naming convention. Signals coming from the DACs have digital volume attenuation controls set in Register R20 (left input digital volume register, Address 0x401A) and Register R21 (right input digital volume register, Address 0x401B). Rev. C | Page 35 of 92 ADAU1761 HEADPHONE OUTPUT Headphone Output Power-Up/Power-Down Sequencing The LHP and RHP pins can be driven by either a line output driver or a headphone driver by setting the HPMODE bit in Register R30 (playback headphone right volume control register, Address 0x4024). The headphone outputs can drive a load of at least 16 Ω. To prevent pops when turning on the headphone outputs, the user must wait at least 4 ms to unmute these outputs after enabling the headphone output with the HPMODE bit. This is because of an internal capacitor that must charge before these outputs can be used. Figure 46 and Figure 47 illustrate the headphone power-up/power-down sequencing. Separate volume controls for the left and right channels range from −57 dB to +6 dB. Slew can be applied to all the playback volume controls using the ASLEW[1:0] bits in Register R34 (playback pop/click suppression register, Address 0x4028). For capless headphones, configure the MONOOUT pin before unmuting the headphone outputs. USER DEFINED Capless Headphone Configuration 4ms HPMODE 1 = HEADPHONE The headphone outputs can be configured in a capless output configuration with the MONOOUT pin used as a dc virtual ground reference. Figure 45 depicts a typical playback path in a capless headphone configuration. Table 19 lists the register settings for this configuration. As shown in this table, the MONOOUT pin outputs common mode (AVDD/2), which is used as the virtual headphone reference. LEFT DAC MX3LM MIXER 3 07680-046 RHPM AND LHPM 1 = UNMUTE INTERNAL PRECHARGE LHPVOL[5:0] Figure 46. Headphone Output Power-Up Timing LHP MX3EN MIXER 7 MIXER 4 MOMODE HPMODE 0 = LINE OUTPUT RHPVOL[5:0] Figure 47. Headphone Output Power-Down Timing 07680-062 RHP MX4EN Ground-Centered Headphone Configuration Figure 45. Capless Headphone Configuration Diagram Table 19. Capless Headphone Register Settings Register R36 R22 R24 R28 R33 R29 R30 Bit Name DACEN[1:0] MX3EN MX3LM MX4EN MX4RM MX7EN MX7[1:0] MONOM MOMODE LHPVOL[5:0] LHPM HPMODE RHPVOL[5:0] RHPM 07680-047 MX7EN MX4RM USER DEFINED MONOOUT MX7[1:0] RIGHT DAC RHPM AND LHPM 0 = MUTE MONOM Setting 11 = both DACs on 1 = enable Mixer 3 1 = unmute left DAC input 1 = enable Mixer 4 1 = unmute right DAC input 1 = enable Mixer 7 00 = common-mode output 1 = unmute mono output 1 = headphone output Desired volume for LHP output 1 = unmute left headphone output 1 = headphone output Desired volume for RHP output 1 = unmute right headphone output The headphone outputs can also be configured as groundcentered outputs by placing coupling capacitors on the LHP and RHP pins. Ground-centered headphones should use the AGND pin as the ground reference. When the headphone outputs are configured in this manner, the capacitors create a high-pass filter on the outputs. The corner frequency of this filter, at which point its attenuation is 3 dB, is calculated by the following formula: f3dB = 1/(2π × R × C) where: C is the capacitor value. R is the impedance of the headphones. For a typical headphone impedance of 16 Ω and a 47 μF capacitor, the corner frequency is 211 Hz. Rev. C | Page 36 of 92 ADAU1761 Jack Detection LINE OUTPUTS When the JACKDET/MICIN pin is set to the jack detect function, a flag on this pin can be used to mute the line outputs when headphones are plugged into the jack. This pin can be configured in Register R2 (digital microphone/jack detection control register, Address 0x4008). The JDFUNC[1:0] bits set the functionality of the JACKDET/MICIN pin. The line output pins (LOUTP, LOUTN, ROUTP, and ROUTN) can be used to drive both differential and single-ended loads. In their default settings, these pins can drive typical line loads of 10 kΩ or greater, but they can also be put into headphone mode by setting the LOMODE bit in Register R31 (playback line output left volume control register, Address 0x4025) and the ROMODE bit in Register R32 (playback line output right volume control register, Address 0x4026). In headphone mode, the line output pins are capable of driving headphone and earpiece speakers of 16 Ω or greater. The output impedance of the line outputs is approximately 1 kΩ. POP-AND-CLICK SUPPRESSION Upon power-up, precharge circuitry is enabled to suppress pops and clicks. After power-up, the precharge circuitry can be put into a low power mode using the POPMODE bit in Register R34 (playback pop/click suppression register, Address 0x4028). The precharge time depends on the capacitor value on the CM pin and the RC time constant of the load. For a typical line output load, the precharge time is between 2 ms and 3 ms. After this precharge time, the POPMODE bit can be set to low power mode. Changing any register settings that affect the signal path can cause pops and clicks on the analog outputs. To avoid these pops and clicks, mute the appropriate outputs using Register R29 to Register R32 (Address 0x4023 to Address 0x4026). Unmute the analog outputs after the changes are made. When the line output pins are used in single-ended mode, LOUTP and ROUTP should be used to output the signals, and LOUTN and ROUTN should be left unconnected. The volume controls for these outputs range from −57 dB to +6 dB. Slew can be applied to all the playback volume controls using the ASLEW[1:0] bits in Register R34 (playback pop/click suppression register, Address 0x4028). The MX5G4[1:0], MX5G3[1:0], MX6G3[1:0], and MX6G4[1:0] bits can all provide a 6 dB gain boost to the line outputs. This gain boost allows single-ended output signals to achieve 0 dBV (1.0 V rms) and differential output signals to achieve up to 6 dBV (2.0 V rms). For more information, see Register R26 (playback L/R mixer left (Mixer 5) line output control register, Address 0x4020) and Register R27 (playback L/R mixer right (Mixer 6) line output control register, Address 0x4021). LEFT DAC MIXER 3 MX5G3[1:0] MIXER 5 LOUTVOL[5:0] LOUTP –1 –1 RIGHT DAC MIXER 4 MX6G4[1:0] MIXER 6 ROUTN ROUTVOL[5:0] ROUTP Figure 48. Differential Line Output Configuration Rev. C | Page 37 of 92 LOUTN 07680-063 Additional settings for jack detection include debounce time (JDDB[1:0] bits) and detection polarity (JDPOL bit). Because the jack detection and digital microphone share a pin, both functions cannot be used simultaneously. ADAU1761 CONTROL PORTS The ADAU1761 can operate in one of two control modes: • • 2 I C control SPI control The ADAU1761 has both a 4-wire SPI control port and a 2-wire I2C bus control port. Both ports can be used to set the registers. The part defaults to I2C mode, but it can be put into SPI control mode by pulling the CLATCH pin low three times. The control port is capable of full read/write operation for all addressable registers. The ADAU1761 must have a valid master clock in order to write to all registers except for Register R0 (Address 0x4000) and Register R1 (Address 0x4002). All addresses can be accessed in both a single-address mode or a burst mode. The first byte (Byte 0) of a control port write contains the 7-bit chip address plus the R/W bit. The next two bytes (Byte 1 and Byte 2) together form the subaddress of the register location within the ADAU1761. This subaddress must be two bytes long because the memory locations within the ADAU1761 are directly addressable and their sizes exceed the range of single-byte addressing. All subsequent bytes (starting with Byte 3) contain the data, such as control port data, program data, or parameter data. The number of bytes per word depends on the type of data that is being written. The ADAU1761 has several mechanisms for updating signal processing parameters in real time without causing pops or clicks. If large blocks of data need to be downloaded, the output of the DSP core can be halted (using the DSPRUN bit in the DSP run register, Address 0x40F6), new data can be loaded, and the device can be restarted. This is typically done during the booting sequence at start-up or when loading a new program into RAM. The control port pins are multifunctional, depending on the mode in which the part is operating. Table 20 describes these multiple functions. Table 20. Control Port Pin Functions Pin Name SCL/CCLK SDA/COUT ADDR1/CDATA ADDR0/CLATCH I2C Mode SCL: input clock SDA: open-collector input/output I2C Address Bit 1: input I2C Address Bit 0: input SPI Mode CCLK: input clock COUT: output CDATA: input CLATCH: input BURST MODE WRITING AND READING Burst mode addressing, where the subaddresses are automatically incremented at word boundaries, can be used for writing large amounts of data to contiguous registers. This increment happens automatically after a single-word write or read unless a stop condition is encountered (I2C) or CLATCH is brought high (SPI). A burst write starts like a single-word write, but following the first data-word, the data-word for the next immediate address can be written immediately without sending its two-byte address. The registers in the ADAU1761 are one byte wide with the exception of the PLL control register, which is six bytes wide. The autoincrement feature knows the word length at each subaddress, so the subaddress does not need to be specified manually for each address in a burst write. The subaddresses are autoincremented by 1 following each read or write of a data-word, regardless of whether there is a valid register or RAM word at that address. Address holes in the register map can be written to or read from without consequence. In the ADAU1761, these address holes exist at Address 0x4001, Address 0x4003 to Address 0x4007, Address 0x402E, Address 0x4032 to Address 0x4035, Address 0x4037 to Address 0x40BF, Address 0x40C5, Address 0x40CA to Address 0x40CF, Address 0x40D5 to Address 0x40EA, and Address 0x40EC to Address 0x40F1. A single-byte write to these registers is ignored by the ADAU1761, and a read returns a single byte 0x00. I2C PORT The ADAU1761 supports a 2-wire serial (I2C-compatible) microprocessor bus driving multiple peripherals. Two pins, serial data (SDA) and serial clock (SCL), carry information between the ADAU1761 and the system I2C master controller. In I2C mode, the ADAU1761 is always a slave on the bus, meaning that it cannot initiate a data transfer. Each slave device is recognized by a unique address. The address and R/W byte format is shown in Table 21. The address resides in the first seven bits of the I2C write. Bits[5:6] of the I2C address for the ADAU1761 are set by the levels on the ADDR1 and ADDR0 pins. The LSB of the address—the R/W bit—specifies either a read or write operation. Logic Level 1 corresponds to a read operation, and Logic Level 0 corresponds to a write operation. Table 21. ADAU1761 I2C Address and Read/Write Byte Format Bit 0 0 Bit 1 1 Bit 2 1 Bit 3 1 Bit 4 0 Bit 5 ADDR1 Bit 6 ADDR0 Bit 7 R/W The SDA and SCL pins should each have a 2 kΩ pull-up resistor on the line connected to it. The voltage on these signal lines should not be higher than IOVDD (1.8 V to 3.3 V). Addressing Initially, each device on the I2C bus is in an idle state and monitors the SDA and SCL lines for a start condition and the proper address. The I2C master initiates a data transfer by establishing a start condition, defined by a high-to-low transition on SDA while SCL remains high. This indicates that an address/ data stream follows. All devices on the bus respond to the start condition and shift the next eight bits (the 7-bit address plus the R/W bit) MSB first. The device that recognizes the transmitted address responds by pulling the data line low during the ninth clock pulse. This ninth bit is known as an acknowledge bit. All other devices withdraw from the bus at this point and return to the idle condition. Rev. C | Page 38 of 92 ADAU1761 the user should only issue one start condition, one stop condition, or a single stop condition followed by a single start condition. If an invalid subaddress is issued by the user, the ADAU1761 does not issue an acknowledge and returns to the idle condition. The R/W bit determines the direction of the data. A Logic 0 on the LSB of the first byte means that the master will write information to the peripheral, whereas a Logic 1 means that the master will read information from the peripheral after writing the subaddress and repeating the start address. A data transfer takes place until a stop condition is encountered. A stop condition occurs when SDA transitions from low to high while SCL is held high. Figure 49 shows the timing of an I2C write, and Figure 50 shows an I2C read. If the user exceeds the highest subaddress while in autoincrement mode, one of two actions is taken. In read mode, the ADAU1761 outputs the highest subaddress register contents until the master device issues a no acknowledge, indicating the end of a read. A no acknowledge condition is where the SDA line is not pulled low on the ninth clock pulse on SCL. If the highest subaddress location is reached while in write mode, the data for the invalid byte is not loaded into any subaddress register, a no acknowledge is issued by the ADAU1761, and the part returns to the idle condition. Stop and start conditions can be detected at any stage during the data transfer. If these conditions are asserted out of sequence with normal read and write operations, the ADAU1761 immediately jumps to the idle condition. During a given SCL high period, SCL 1 0 SDA 1 1 R/W 0 ADDR1 ADDR0 START BY MASTER ACK BY ADAU1761 ACK BY ADAU1761 FRAME 1 CHIP ADDRESS BYTE FRAME 2 SUBADDRESS BYTE 1 SCL (CONTINUED) ACK BY ADAU1761 FRAME 3 SUBADDRESS BYTE 2 ACK BY ADAU1761 FRAME 4 DATA BYTE 1 STOP BY MASTER 07680-032 SDA (CONTINUED) Figure 49. I2C Write to ADAU1761 Clocking SCL SDA START BY MASTER 0 1 1 1 0 R/W ADDR1 ADDR0 ACK BY ADAU1761 ACK BY ADAU1761 FRAME 1 CHIP ADDRESS BYTE FRAME 2 SUBADDRESS BYTE 1 SCL (CONTINUED) SDA (CONTINUED) 0 FRAME 3 SUBADDRESS BYTE 2 ACK BY ADAU1761 1 REPEATED START BY MASTER 1 1 0 R/W ADDR1 ADDR0 ACK BY ADAU1761 FRAME 4 CHIP ADDRESS BYTE SCL (CONTINUED) ACK BY MASTER STOP BY MASTER FRAME 5 READ DATA BYTE 1 Figure 50. I2C Read from ADAU1761 Clocking Rev. C | Page 39 of 92 07680-033 SDA (CONTINUED) ADAU1761 I2C Read and Write Operations This causes the ADAU1761 SDA to reverse and begin driving data back to the master. The master then responds every ninth pulse with an acknowledge pulse to the ADAU1761. Figure 51 shows the format of a single-word write operation. Every ninth clock pulse, the ADAU1761 issues an acknowledge by pulling SDA low. Figure 54 shows the format of a burst mode read sequence. This figure shows an example of a read from sequential single-byte registers. The ADAU1761 increments its subaddress register after every byte because the requested subaddress corresponds to a register or memory area with a 1-byte word length. The ADAU1761 always decodes the subaddress and sets the autoincrement circuit so that the address increments after the appropriate number of bytes. Figure 52 shows the format of a burst mode write sequence. This figure shows an example of a write to sequential single-byte registers. The ADAU1761 increments its subaddress register after every byte because the requested subaddress corresponds to a register or memory area with a 1-byte word length. Figure 53 shows the format of a single-word read operation. Note that the first R/W bit is 0, indicating a write operation. This is because the subaddress still needs to be written to set up the internal address. After the ADAU1761 acknowledges the receipt of the subaddress, the master must issue a repeated start command followed by the chip address byte with the R/W bit set to 1 (read). S AS Chip address, R/W = 0 Subaddress high byte Figure 51 to Figure 54 use the following abbreviations: S = start bit P = stop bit AM = acknowledge by master AS = acknowledge by slave AS Subaddress low byte AS Data Byte 1 P Figure 51. Single-Word I2C Write Format S Chip address, R/W = 0 AS Subaddress high byte AS Subaddress low byte AS AS Data Byte 1 AS Data Byte 2 Data Byte 3 AS Data Byte 4 AS … P Figure 52. Burst Mode I2C Write Format S Chip address, R/W = 0 AS Subaddress high byte AS Subaddress low byte AS S Chip address, R/W = 1 AS P Data Byte 1 Figure 53. Single-Word I2C Read Format S Chip address, R/W = 0 AS Subaddress high byte AS Subaddress low byte AS S Chip address, R/W = 1 Figure 54. Burst Mode I2C Read Format Rev. C | Page 40 of 92 AS Data Byte 1 AM Data Byte 2 AM … P ADAU1761 SPI PORT Chip Address R/W 2 By default, the ADAU1761 is in I C mode, but it can be put into SPI control mode by pulling CLATCH low three times. This is done by performing three dummy writes to the SPI port (the ADAU1761 does not acknowledge these three writes). Beginning with the fourth SPI write, data can be written to or read from the IC. The ADAU1761 can be taken out of SPI mode only by a full reset initiated by power-cycling the IC. The LSB of the first byte of an SPI transaction is a R/W bit. This bit determines whether the communication is a read (Logic Level 1) or a write (Logic Level 0). This format is shown in Table 22. The SPI port uses a 4-wire interface, consisting of the CLATCH, CCLK, CDATA, and COUT signals, and it is always a slave port. The CLATCH signal should go low at the beginning of a transaction and high at the end of a transaction. The CCLK signal latches CDATA on a low-to-high transition. COUT data is shifted out of the ADAU1761 on the falling edge of CCLK and should be clocked into a receiving device, such as a microcontroller, on the CCLK rising edge. The CDATA signal carries the serial input data, and the COUT signal carries the serial output data. The COUT signal remains three-state until a read operation is requested. This allows other SPI-compatible peripherals to share the same readback line. All SPI transactions have the same basic format shown in Table 23. A timing diagram is shown in Figure 4. All data should be written MSB first. Subaddress Table 22. ADAU1761 SPI Address and Read/Write Byte Format Bit 0 0 Bit 1 0 Bit 2 0 Bit 3 0 Bit 4 0 Bit 5 0 Bit 6 0 The 16-bit subaddress word is decoded into a location in one of the registers. This subaddress is the location of the appropriate register. The MSBs of the subaddress are zero-padded to bring the word to a full 2-byte length. Data Bytes The number of data bytes varies according to the register being accessed. During a burst mode write, an initial subaddress is written followed by a continuous sequence of data for consecutive register locations. A sample timing diagram for a single-word SPI write operation to a register is shown in Figure 55. A sample timing diagram of a single-word SPI read operation is shown in Figure 56. The COUT pin goes from being three-state to being driven at the beginning of Byte 3. In this example, Byte 0 to Byte 2 contain the addresses and R/W bit, and subsequent bytes carry the data. Table 23. Generic Control Word Format Byte 0 chip_adr[6:0], R/W Byte 2 subaddr[7:0] Byte 3 data Byte 4 1 data Continues to end of data. CLATCH CDATA BYTE 0 BYTE 1 BYTE 2 07680-038 CCLK BYTE 3 Figure 55. SPI Write to ADAU1761 Clocking (Single-Word Write Mode) CLATCH CCLK CDATA COUT BYTE 1 BYTE 0 BYTE 2 HIGH-Z DATA Figure 56. SPI Read from ADAU1761 Clocking (Single-Word Read Mode) Rev. C | Page 41 of 92 HIGH-Z 07680-039 1 Byte 1 subaddr[15:8] Bit 7 R/W ADAU1761 SERIAL DATA INPUT/OUTPUT PORTS If the PLL of the ADAU1761 is not used, the serial data clocks must be synchronous with the ADAU1761 master clock input. The LRCLK and BCLK pins are used to clock both the serial input and output ports. The ADAU1761 can be set as the master or the slave in a system. Because there is only one set of serial data clocks, the input and output ports must always be both master or both slave. Register R15 and Register R16 (serial port control registers, Address 0x4015 and Address 0x4016) allow control of clock polarity and data input modes. The valid data formats are I2S, left-justified, right-justified (24-/20-/18-/16-bit), and TDM. In all modes except for the right-justified modes, the serial port inputs an arbitrary number of bits up to a limit of 24. Extra bits do not cause an error, but they are truncated internally. The serial port can operate with an arbitrary number of BCLK transitions in each LRCLK frame. The LRCLK in TDM mode can be input to the ADAU1761 either as a 50% duty cycle clock or as a bit-wide pulse. When the LRCLK is set as a pulse, a 47 pF capacitor should be connected between the LRCLK pin and ground (see Figure 57). This capacitor is necessary in both master and slave modes to properly align the LRCLK signal to the serial data stream. ADAU1761 LRCLK 47pF BCLK 07680-071 The flexible serial data input and output ports of the ADAU1761 can be set to accept or transmit data in 2-channel format or in a 4-channel or 8-channel TDM stream to interface to external ADCs or DACs. Data is processed in twos complement, MSB first format. The left channel data field always precedes the right channel data field in 2-channel streams. In TDM mode, Slot 0 to Slot 3 are in the first half of the audio frame, and Slot 4 to Slot 7 are in the second half of the frame. The serial modes and the position of the data in the frame are set in Register R15 to Register R18 (serial port and converter control registers, Address 0x4015 to Address 0x4018). Figure 57. LRCLK Capacitor Alignment, TDM Pulse Mode In TDM 8 mode, the ADAU1761 can be a master for fS up to 48 kHz. Table 24 lists the modes in which the serial output port can function. Table 24. Serial Output Port Master/Slave Mode Capabilities fS 48 kHz 96 kHz 2-Channel Modes (I2S, LeftJustified, Right-Justified) Master and slave Master and slave 8-Channel TDM Master and slave Slave Table 25 describes the proper configurations for standard audio data formats. Table 25. Data Format Configurations Format I2S (see Figure 58) Left-Justified (see Figure 59) Right-Justified (see Figure 60) TDM with Clock (see Figure 61) TDM with Pulse (see Figure 62) LRCLK Polarity (LRPOL) Frame begins on falling edge LRCLK Mode (LRMOD) 50% duty cycle Frame begins on rising edge 50% duty cycle Frame begins on rising edge 50% duty cycle Frame begins on falling edge 50% duty cycle Frame begins on rising edge Pulse BCLK Polarity (BPOL) Data changes on falling edge Data changes on falling edge Data changes on falling edge Data changes on falling edge Data changes on falling edge Rev. C | Page 42 of 92 BCLK Cycles/Audio Frame (BPF[2:0]) 32 to 64 32 to 64 32 to 64 64 to 256 64 to 256 Data Delay from LRCLK Edge (LRDEL[1:0]) Delayed from LRCLK edge by 1 BCLK Aligned with LRCLK edge Delayed from LRCLK edge by 8 or 16 BCLKs Delayed from start of word clock by 1 BCLK Delayed from start of word clock by 1 BCLK ADAU1761 LEFT CHANNEL LRCLK RIGHT CHANNEL BCLK LSB MSB LSB MSB 07680-040 SDATA 1/fS 2 Figure 58. I S Mode—16 Bits to 24 Bits per Channel MSB LSB MSB LSB 07680-041 SDATA RIGHT CHANNEL LEFT CHANNEL LRCLK BCLK 1/fS Figure 59. Left-Justified Mode—16 Bits to 24 Bits per Channel RIGHT CHANNEL SDATA MSB LSB MSB LSB 07680-042 LEFT CHANNEL LRCLK BCLK 1/fS Figure 60. Right-Justified Mode—16 Bits to 24 Bits per Channel LRCLK 256 BCLKs BCLK SDATA 32 BCLKs SLOT 0 SLOT 1 SLOT 2 SLOT 3 SLOT 4 SLOT 5 SLOT 6 SLOT 7 LRCLK MSB – 1 MSB – 2 07680-043 BCLK MSB SDATA Figure 61. TDM 8 Mode LRCLK BCLK MSB TDM MSB TDM CH 8 CH 0 SLOT 0 SLOT 1 SLOT 2 SLOT 3 SLOT 4 SLOT 5 SLOT 6 SLOT 7 07680-044 SDATA 32 BCLKs Figure 62. TDM 8 Mode with Pulse Word Clock Rev. C | Page 43 of 92 ADAU1761 APPLICATIONS INFORMATION POWER SUPPLY BYPASS CAPACITORS GROUNDING Each analog and digital power supply pin should be bypassed to its nearest appropriate ground pin with a single 100 nF capacitor. The connections to each side of the capacitor should be as short as possible, and the trace should stay on a single layer with no vias. For maximum effectiveness, locate the capacitor equidistant from the power and ground pins or, when equidistant placement is not possible, slightly closer to the power pin. Thermal connections to the ground planes should be made on the far side of the capacitor. A single ground plane should be used in the application layout. Components in an analog signal path should be placed away from digital signals. Each supply signal on the board should also be bypassed with a single bulk capacitor (10 μF to 47 μF). VDD EXPOSED PAD PCB DESIGN The ADAU1761 has an exposed pad on the underside of the LFCSP. This pad is used to couple the package to the PCB for heat dissipation when using the outputs to drive earpiece or headphone loads. When designing a board for the ADAU1761, special consideration should be given to the following: • GND • CAPACITOR A copper layer equal in size to the exposed pad should be on all layers of the board, from top to bottom, and should connect somewhere to a dedicated copper board layer (see Figure 65). Vias should be placed to connect all layers of copper, allowing for efficient heat and energy conductivity. For an example, see Figure 66, which has nine vias arranged in a 3 inch × 3 inch grid in the pad area. 07680-048 TO GND TOP GROUND POWER BOTTOM Figure 63. Recommended Power Supply Bypass Capacitor Layout VIAS COPPER SQUARES Figure 65. Exposed Pad Layout Example, Side View GSM NOISE FILTER In mobile phone applications, excessive 217 Hz GSM noise on the analog supply pins can degrade the audio quality. To avoid this problem, it is recommended that an L-C filter be used in series with the bypass capacitors for the AVDD pins. This filter should consist of a 1.2 nH inductor and a 9.1 pF capacitor in series between AVDD and ground, as shown in Figure 64. 10µF 07680-051 + 0.1µF 0.1µF 1.2nH 9.1pF AVDD 07680-049 AVDD Figure 66. Exposed Pad Layout Example, Top View Figure 64. GSM Filter on the Analog Supply Pins Rev. C | Page 44 of 92 07680-050 TO VDD ADAU1761 DSP CORE SIGNAL PROCESSING PROGRAM COUNTER The ADAU1761 is designed to provide all audio signal processing functions commonly used in stereo or mono low power record and playback systems. The signal processing flow is designed using the SigmaStudio software, which allows graphical entry and real-time control of all signal processing functions. The execution of instructions in the core is governed by a program counter, which sequentially steps through the addresses of the program RAM. The program counter starts every time that a new audio frame is clocked into the core. SigmaStudio inserts a jump-to-start command at the end of every program. The program counter increments sequentially until it reaches this command and then jumps to the program start address and waits for the next audio frame to clock into the core. Many of the signal processing functions are coded using full, 56-bit, double-precision arithmetic data. The input and output word lengths of the DSP core are 24 bits. Four extra headroom bits are used in the processor to allow internal gains of up to 24 dB without clipping. Additional gains can be achieved by initially scaling down the input signal in the DSP signal flow. ARCHITECTURE The DSP core consists of a simple 28-/56-bit multiply-accumulate (MAC) unit with two sources: a data source and a coefficient source. The data source can come from the data RAM, a ROM table of commonly used constant values, or the audio inputs to the core. The coefficient source can come from the parameter RAM or from a ROM table of commonly used constant values. The two sources are multiplied in a 28-bit fixed-point multiplier and then the signal is input to the 56-bit adder; the result is usually stored in one of three 56-bit accumulator registers. The accumulators can be output from the core (in 28-bit format) or can optionally be written back into the data or parameter RAMs. DATA SOURCE (DATA RAM, ROM CONSTANTS, AUDIO INPUTS) 28 56 The SigmaDSP core was designed specifically for audio processing and therefore includes several features intended for maximizing efficiency. These include hardware decibel conversion and audiospecific ROM constants. STARTUP Before the DSPRUN bit is set or any settings are written to the parameter RAM, the DSP core must be enabled by setting the DSPEN bit in Register R61 (Address 0x40F5). The following steps should be performed every time that a new program is loaded to the SigmaDSP core, or any time that the DSPRUN bit is disabled and reenabled. 1. 2. 3. 4. 5. COEFFICIENT SOURCE (PARAMETER RAM, ROM CONSTANTS) 28 FEATURES Changing any register setting or RAM can cause pops and clicks on the analog outputs. To avoid these pops and clicks, mute the appropriate outputs using Register R29 to Register R32 (Address 0x4023 to Address 0x4026). Unmute the analog outputs after the startup procedure is completed. 28 TRUNCATOR 56 56 DATA OPERATIONS (ACCUMULATORS (3), dB CONVERSION, BIT OPERATORS, BIT SHIFTER, ...) 56 TRUNCATOR 07680-067 28 OUTPUTS Set the DSPSR[3:0] bits in Register R57 (Address 0x40EB) to 1111 (none). Set the DSPRUN bit in Register R62 (Address 0x40F6) to 0. Download the rest of the registers, the program RAM, and the parameter RAM. Set the DSPRUN bit in Register R62 to 1. Set the DSPSR[3:0] bits in Register R57 to the operational setting (default value is 0001). Figure 67. Simplified DSP Core Architecture Rev. C | Page 45 of 92 ADAU1761 NUMERIC FORMATS DSP systems commonly use a standard numeric format. Fractional numeric systems are specified by an A.B format, where A is the number of bits to the left of the decimal point and B is the number of bits to the right of the decimal point. The ADAU1761 uses numeric format 5.23 for both the parameter and data values. Numeric Format 5.23 The serial port accepts up to 24 bits on the input and is signextended to the full 28 bits of the DSP core. This allows internal gains of up to 24 dB without internal clipping. A digital clipper circuit is used between the output of the DSP core and the DACs or serial port outputs (see Figure 68). This circuit clips the top four bits of the signal to produce a 24-bit output with a range of 1.0 (minus 1 LSB) to −1.0. Figure 68 shows the maximum signal levels at each point in the data flow in both binary and decibel levels. Linear range: −16.0 to (+16.0 − 1 LSB) DATA IN 1.23 (0dB) SERIAL PORT 1.23 (0dB) SIGNAL PROCESSING (5.23 FORMAT) 5.23 (24dB) DIGITAL CLIPPER 5.23 (24dB) 1.23 (0dB) Figure 68. Numeric Precision and Clipping Structure PROGRAMMING On power-up, the ADAU1761 must be configured with a clocking scheme and then loaded with register settings. After the codec signal path is set up, the DSP core can be programmed. There are 1024 instruction cycles per audio sample, resulting in an internal clock rate of 49.152 MHz when fS = 48 kHz. The part can be programmed easily using SigmaStudio, a graphical tool provided by Analog Devices (see Figure 69). No knowledge of writing line-level DSP code is required. More information about SigmaStudio can be found at www.analog.com. 07680-069 Examples: 1000 0000 0000 0000 0000 0000 0000 = −16.0 1110 0000 0000 0000 0000 0000 0000 = −4.0 1111 1000 0000 0000 0000 0000 0000 = −1.0 1111 1110 0000 0000 0000 0000 0000 = −0.25 1111 1111 0011 0011 0011 0011 0011 = −0.1 1111 1111 1111 1111 1111 1111 1111 = (1 LSB below 0) 0000 0000 0000 0000 0000 0000 0000 = 0 0000 0000 1100 1100 1100 1100 1101 = 0.1 0000 0010 0000 0000 0000 0000 0000 = 0.25 0000 1000 0000 0000 0000 0000 0000 = 1.0 0010 0000 0000 0000 0000 0000 0000 = 4.0 0111 1111 1111 1111 1111 1111 1111 = (16.0 − 1 LSB) 07680-068 4-BIT SIGN EXTENSION Figure 69. SigmaStudio Screen Shot Rev. C | Page 46 of 92 ADAU1761 PROGRAM RAM, PARAMETER RAM, AND DATA RAM Table 26. RAM Map and Read/Write Modes Memory Parameter RAM Program RAM Size 1024 × 32 1024 × 40 Address Range 0 to 1023 (0x0000 to 0x03FF) 2048 to 3071 (0x0800 to 0x0BFF) Table 26 shows the RAM map (the ADAU1761 register map is provided in the Control Registers section). The address space encompasses a set of registers and three RAMs: program, parameter, and data. The program RAM and parameter RAM are not initialized on power-up and are in an unknown state until written to. PROGRAM RAM The program RAM contains the 40-bit operation codes that are executed by the core. The SigmaStudio compiler calculates maximum instructions per frame for a project and generates an error when the value exceeds the maximum allowable instructions per frame based on the sample rate of the signals in the core. Because the end of a program contains a jump-to-start command, the unused program RAM space does not need to be filled with no-operation (NOP) commands. PARAMETER RAM The parameter RAM is 32 bits wide and occupies Address 0 to Address 1023. Each parameter is padded with four 0s before the MSB to extend the 28-bit word to a full 4-byte width. The data format of the parameter RAM is twos complement, 5.23. This means that the coefficients can range from +16.0 (minus 1 LSB) to −16.0, with 1.0 represented by the binary word 0000 1000 0000 0000 0000 0000 0000 or by the hexadecimal word 0x00 0x80 0x00 0x00. The parameter RAM can be written to directly or with a safeload write. The direct write mode of operation is typically used during a complete new loading of the RAM using burst mode addressing to avoid any clicks or pops in the outputs. Note that this mode can be used during live program execution, but because there is no handshaking between the core and the control port, the parameter RAM is unavailable to the DSP core during control writes, resulting in pops and clicks in the audio stream. SigmaStudio automatically assigns the first eight positions to safeload parameters; therefore, project-specific parameters start at Address 0x0008. The parameter RAM should not be written to until the DSPEN bit has been set in Register R61 (Address 0x40F5). DATA RAM Read Yes Yes Write Yes Yes Write Modes Direct, safeload Direct When implementing blocks, such as delays, that require large amounts of data RAM space, data RAM utilization should be taken into account. The SigmaDSP core processes delay times in one-sample increments; therefore, the total pool of delay available to the user equals 4096 multiplied by the sample period. For a fS,DSP of 48 kHz, the pool of available delay is a maximum of about 86 ms, where fS,DSP is the DSP core sampling rate. In practice, this much data memory is not available to the user because every block in a design uses a few data memory locations for its processing. In most DSP programs, this does not significantly affect the total delay time. The SigmaStudio compiler manages the data RAM and indicates whether the number of addresses needed in the design exceeds the maximum number available. READ/WRITE DATA FORMATS The read/write formats of the control port are designed to be byte oriented to allow for easy programming of common microcontroller chips. To fit into a byte-oriented format, 0s are added to the data fields before the MSB to extend the data-word to eight bits. For example, 28-bit words written to the parameter RAM are preceded by four leading 0s to equal 32 bits (four bytes); 40-bit words written to the program RAM are not preceded by 0s because they are already a full five bytes. These zero-padded data fields are appended to a 3-byte field consisting of a 7-bit chip address, a read/write bit, and a 16-bit RAM/register address. The control port knows how many data bytes to expect based on the address given in the first three bytes. The total number of bytes for a single-location write command can vary from one byte (for a control register write) to five bytes (for a program RAM write). Burst mode can be used to fill contiguous register or RAM locations. A burst mode write begins by writing the address and data of the first RAM or register location to be written. Rather than ending the control port transaction (by issuing a stop command in I2C mode or by bringing the CLATCH signal high in SPI mode after the data-word), as would be done in a single-address write, the next data-word can be written immediately without specifying its address. The ADAU1761 control port autoincrements the address of each write even across the boundaries of the different RAMs and registers. Table 28 and Table 30 show examples of burst mode writes. The ADAU1761 data RAM is used to store audio data-words for processing, as well as certain run-time parameters. SigmaStudio provides the data and address information for writing to and reading from the data RAM. Rev. C | Page 47 of 92 ADAU1761 Table 27. Parameter RAM Read/Write Format (Single Address) Byte 0 chip_adr[6:0], R/W Byte 1 param_adr[15:8] Byte 2 param_adr[7:0] Byte 3 0000, param[27:24] Bytes[4:6] param[23:0] Table 28. Parameter RAM Block Read/Write Format (Burst Mode) Byte 0 chip_adr[6:0], R/W Byte 1 param_adr[15:8] Byte 2 param_adr[7:0] Byte 3 0000, param[27:24] Bytes[4:6] param[23:0] <—param_adr—> Bytes[7:10] Bytes[11:14] param_adr + 1 param_adr + 2 Table 29. Program RAM Read/Write Format (Single Address) Byte 0 chip_adr[6:0], R/W Byte 1 prog_adr[15:8] Byte 2 prog_adr[7:0] Bytes[3:7] prog[39:0] Table 30. Program RAM Block Read/Write Format (Burst Mode) Byte 0 chip_adr[6:0], R/W Byte 1 prog_adr[15:8] Byte 2 prog_adr[7:0] SOFTWARE SAFELOAD To update parameters in real time while avoiding pop and click noises on the output, the ADAU1761 uses a software safeload mechanism. The software safeload mechanism enables the SigmaDSP core to load new parameters into RAM while guaranteeing that the parameters are not in use. This prevents an undesirable condition where an instruction could execute with a mix of old and new parameters. SigmaStudio sets up the necessary code and parameters automatically for new projects. The safeload code, along with other initialization code, fills the first 39 locations in program RAM. The first eight parameter RAM locations (Address 0x0000 to Address 0x0007) are configured by default in SigmaStudio as described in Table 31. Table 31. Software Safeload Parameter RAM Defaults Address (Hex) 0x0000 0x0001 0x0002 0x0003 0x0004 0x0005 0x0006 0x0007 Function Modulo RAM size Safeload Data 1 Safeload Data 2 Safeload Data 3 Safeload Data 4 Safeload Data 5 Safeload target address (offset of −1) Number of words to write/safeload trigger Bytes[3:7] prog[39:0] Bytes[8:12] Bytes[13:17] <—prog_adr—> prog_adr + 1 prog_adr + 2 Parameter RAM Address 0x0001 to Address 0x0005 are the five data slots for storing the data to be safeloaded. The safeload parameter space contains five data slots by default because most standard signal processing algorithms have five parameters or less. Address 0x0006 is the target address in parameter RAM (with an offset of −1). This designates the first address to be written. If more than one word is written, the address increments automatically for each data-word. Up to five sequential parameter RAM locations can be updated with safeload during each audio frame. The target address offset of −1 is used because the write address is calculated relative to the address of the data, which starts at Address 0x0001. Therefore, to update a parameter at Address 0x000A, the target address is 0x0009. Address 0x0007 designates the number of words to be written into the parameter RAM during the safeload. A biquad filter uses all five safeload data addresses. A simple mono gain cell uses only one safeload data address. Writing to Address 0x0007 also triggers the safeload write to occur in the next audio frame. The safeload mechanism is software based and executes once per audio frame. Therefore, system designers must take care when designing the communication protocol. A delay equal to or greater than the sampling period (the inverse of sampling frequency) is required between each safeload write. A sample rate of 48 kHz equates to a delay of at least 21 μs. If this delay is not observed, the downloaded data is corrupted. Address 0x0000, which controls the modulo RAM size, is set by SigmaStudio and is based on the dynamic address generator mode of the project. Rev. C | Page 48 of 92 ADAU1761 SOFTWARE SLEW Because algorithms that use software slew generally require more RAM than their nonslew equivalents, they should be used only in situations where a parameter will change during operation of the device. Figure 70 shows an example of volume slew applied to a sine wave. The target value takes an additional space in parameter RAM, and the current value of the parameter is updated in the nonmodulo section of data RAM. Assignment of parameters and nonmodulo data RAM is handled by the SigmaStudio compiler and does not need to be programmed manually. Slew parameters can follow several different curves, including an RC-type curve and a linear curve. These curve types are coded into each algorithm and cannot be modified by the user. Rev. C | Page 49 of 92 NEW TARGET VALUE SLEW CURVE INITIAL VALUE 07680-070 When the values of signal processing parameters are changed abruptly in real time, they sometimes cause pop and click sounds to appear on the audio outputs. To avoid pops and clicks, some algorithms in SigmaStudio implement a software slew functionality. Algorithms using software slew set a target value for a parameter and continuously update the value of that parameter until it reaches the target. Figure 70. Example of Volume Slew ADAU1761 GENERAL-PURPOSE INPUT/OUTPUT The serial data input/output pins (Pin 26 to Pin 29) are shared with the general-purpose input/output function. Each of these four pins can be set to only one of these functions. The function of these pins is set in the serial data/GPIO pin configuration register (Register R60, Address 0x40F4). The GPIOx pins can be used as inputs or outputs. These pins are readable and can be set through the control port or directly by the SigmaDSP core. When configured as inputs, the GPIOx pins can be used with push-button switches or rotary encoders to control DSP program settings. These pins can also be used with digital outputs to drive LEDs or external logic to indicate the status of internal signals and control other devices. Examples of this use include indicating signal overload, signal present, and button press confirmation. When configured as an output, each GPIO pin can typically drive 2 mA, which is enough current to directly drive some high efficiency LEDs. Standard LEDs require about 20 mA of current and can be driven from a GPIO output with an external transistor or buffer. Because of problems that can arise from simultaneously driving or sinking a large amount of current on many pins, avoid connecting high efficiency LEDs directly to many or all of the GPIO pins when designing the application. If many LEDs are required, use an external driver. When the GPIO pins are configured as open-collector outputs, they should be pulled up to a maximum voltage equal to the voltage set on IOVDD. The configuration of the GPIO functions is set up in the GPIO pin control registers (Register R48 to Register R51, Address 0x40C6 to Address 0x40C9). GPIO PINS SET FROM THE CONTROL PORT The GPIO pins can also be configured to be directly controlled from the I2C/SPI control port. When the pins are set to this mode, four memory locations are enabled for the GPIO pin settings. The physical settings on the GPIO pins mirror the settings of the LSB of these 4-byte-wide memory locations. Table 32. GPIOx Pin Memory Settings (Set from Control Port) Memory Location Decimal Hex 1568 0x0620 1569 0x0621 1570 0x0622 1571 0x0623 Rev. C | Page 50 of 92 Bits[31:1] Reserved Reserved Reserved Reserved Bit 0 GPIO0SET GPIO1SET GPIO2SET GPIO3SET ADAU1761 CONTROL REGISTERS Table 33. Register Map Reg R0 R1 Address 0x4000 0x4002 Name Clock control PLL control Bit 7 Reserved R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29 R30 R31 R32 R33 R34 R35 R36 R37 R38 R39 R40 R41 R42 R67 R43 R44 R45 R46 0x4008 0x4009 0x400A 0x400B 0x400C 0x400D 0x400E 0x400F 0x4010 0x4011 0x4012 0x4013 0x4014 0x4015 0x4016 0x4017 0x4018 0x4019 0x401A 0x401B 0x401C 0x401D 0x401E 0x401F 0x4020 0x4021 0x4022 0x4023 0x4024 0x4025 0x4026 0x4027 0x4028 0x4029 0x402A 0x402B 0x402C 0x402D 0x402F 0x4030 0x4031 0x4036 0x40C0 0x40C1 0x40C2 0x40C3 Dig mic/jack detect Rec power mgmt Rec Mixer Left 0 Rec Mixer Left 1 Rec Mixer Right 0 Rec Mixer Right 1 Left diff input vol Right diff input vol Record mic bias ALC 0 ALC 1 ALC 2 ALC 3 Serial Port 0 Serial Port 1 Converter 0 Converter 1 ADC control Left digital vol Right digital vol Play Mixer Left 0 Play Mixer Left 1 Play Mixer Right 0 Play Mixer Right 1 Play L/R mixer left Play L/R mixer right Play L/R mixer mono Play HP left vol Play HP right vol Line output left vol Line output right vol Play mono output Pop/click suppress Play power mgmt DAC Control 0 DAC Control 1 DAC Control 2 Serial port pad Control Port Pad 0 Control Port Pad 1 Jack detect pin Dejitter control Cyclic redundancy check Bit 6 Bit 5 Reserved Bit 4 R[3:0] Reserved JDFUNC[1:0] Bit 3 CLKSRC M[15:8] M[7:0] N[15:8] N[7:0] Bit 2 Bit 1 INFREQ[1:0] Bit 0 COREN X[1:0] Type Lock PLLEN Reserved JDPOL RBIAS[1:0] Reserved LINNG[2:0] MX1EN MX1AUXG[2:0] RINNG[2:0] MX2EN MX2AUXG[2:0] LDMUTE LDEN RDMUTE RDEN MBI Reserved MBIEN ALCSEL[2:0] ALCTARG[3:0] ALCDEC[3:0] NGTHR[4:0] CHPF[1:0] MS MSBP LRDEL[1:0] CONVSR[2:0] ADPAIR[1:0] INSEL ADCEN[1:0] JDDB[1:0] Reserved MXBIAS[1:0] ADCBIAS[1:0] Reserved LINPG[2:0] Reserved LDBOOST[1:0] Reserved RINPG[2:0] Reserved RDBOOST[1:0] LDVOL[5:0] RDVOL[5:0] Reserved MPERF PGASLEW[1:0] ALCMAX[2:0] ALCHOLD[3:0] ALCATCK[3:0] NGTYP[1:0] NGEN Reserved SPSRS LRMOD BPOL LRPOL BPF[2:0] ADTDM DATDM Reserved DAPAIR[1:0] DAOSR ADOSR Reserved Reserved ADCPOL HPF DMPOL DMSW LADVOL[7:0] RADVOL[7:0] Reserved MX3RM MX3LM MX3AUXG[3:0] MX3EN MX3G2[3:0] MX3G1[3:0] Reserved MX4RM MX4LM MX4AUXG[3:0] MX4EN MX4G2[3:0] MX4G1[3:0] Reserved MX5G4[1:0] MX5G3[1:0] MX5EN Reserved MX6G4[1:0] MX6G3[1:0] MX6EN Reserved MX7[1:0] MX7EN LHPVOL[5:0] LHPM HPEN RHPVOL[5:0] RHPM HPMODE LOUTVOL[5:0] LOUTM LOMODE ROUTVOL[5:0] ROUTM ROMODE MONOVOL[5:0] MONOM MOMODE Reserved POPMODE POPLESS ASLEW[1:0] Reserved HPBIAS[1:0] DACBIAS[1:0] PBIAS[1:0] PREN PLEN DACMONO[1:0] DACPOL Reserved DEMPH DACEN[1:0] LDAVOL[7:0] RDAVOL[7:0] ADCSDP[1:0] DACSDP[1:0] LRCLKP[1:0] BCLKP[1:0] CDATP[1:0] CLCHP[1:0] SCLP[1:0] SDAP[1:0] Reserved SDASTR Reserved JDSTR Reserved JDP[1:0] Reserved DEJIT[7:0] CRC[31:24] CRC[23:16] CRC[15:8] CRC[7:0] Rev. C | Page 51 of 92 Default 00000000 00000000 11111101 00000000 00001100 00010000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00010000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000010 00000010 00000010 00000010 00000010 00000000 00000000 00000000 00000000 00000000 10101010 10101010 00000000 00001000 00000011 00000000 00000000 00000000 00000000 ADAU1761 Reg R47 R48 R49 R50 R51 R52 R53 R54 R55 R56 R57 Address 0x40C4 0x40C6 0x40C7 0x40C8 0x40C9 0x40D0 0x40D1 0x40D2 0x40D3 0x40D4 0x40EB R58 0x40F2 R59 0x40F3 R60 0x40F4 R61 R62 R63 R64 0x40F5 0x40F6 0x40F7 0x40F8 R65 R66 0x40F9 0x40FA Name CRC enable GPIO0 pin control GPIO1 pin control GPIO2 pin control GPIO3 pin control Watchdog enable Watchdog value Watchdog error DSP sampling rate setting Serial input route control Serial output route control Serial data/GPIO pin configuration DSP enable DSP run DSP slew modes Serial port sampling rate Clock Enable 0 Clock Enable 1 Bit 7 Bit 6 Bit 5 Bit 4 Reserved Bit 3 Bit 2 Reserved DSPSR[3:0] Default 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000001 Reserved SINRT[3:0] 00000000 Reserved SOUTRT[3:0] 00000000 Reserved Reserved Reserved Reserved Bit 1 GPIO0[3:0] GPIO1[3:0] GPIO2[3:0] GPIO3[3:0] Reserved DOG[23:16] DOG[15:8] DOG[7:0] Reserved Reserved DOGEN DOGER LRGP3 Reserved Reserved MOSLW Reserved BGP2 SLEWPD ALCPD DECPD Reserved SDOGP1 ROSLW LOSLW RHPSLW SPSR[2:0] SOUTPD INTPD SINPD CLK1 Reserved Reserved Bit 0 CRCEN SDIGP0 00000000 DSPEN DSPRUN LHPSLW 00000000 00000000 00000000 00000000 SPPD CLK0 00000000 00000000 CONTROL REGISTER DETAILS All registers except for the PLL control register are 1-byte write and read registers. R0: Clock Control, 16,384 (0x4000) Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 CLKSRC Bit 2 Bit 1 INFREQ[1:0] Bit 0 COREN Table 34. Clock Control Register Bits 3 Bit Name CLKSRC [2:1] INFREQ[1:0] 0 COREN Description Clock source select. 0 = direct from MCLK pin (default). 1 = PLL clock. Input clock frequency. Sets the core clock rate that generates the core clock. If the PLL is used, this value is automatically set to 1024 × fS. Setting Input Clock Frequency 00 256 × fS (default) 01 512 × fS 10 768 × fS 11 1024 × fS Core clock enable. Only the R0 and R1 registers can be accessed when this bit is set to 0 (core clock disabled). 0 = core clock disabled (default). 1 = core clock enabled. Rev. C | Page 52 of 92 ADAU1761 R1: PLL Control, 16,386 (0x4002) Byte 0 1 2 3 4 5 Bit 7 Bit 6 Reserved Bit 5 Bit 4 Bit 3 M[15:8] M[7:0] N[15:8] N[7:0] R[3:0] Reserved Bit 2 Bit 1 X[1:0] Lock Bit 0 Type PLLEN Table 35. PLL Control Register Byte 0 1 Bits [7:0] [7:0] Bit Name M[15:8] M[7:0] 2 3 [7:0] [7:0] N[15:8] N[7:0] 4 [6:3] R[3:0] 4 [2:1] X[1:0] 4 0 Type 5 1 Lock 5 0 PLLEN Description PLL denominator MSB. This value is concatenated with M[7:0] to make up a 16-bit number. PLL denominator LSB. This value is concatenated with M[15:8] to make up a 16-bit number. M[15:8] (MSB) M[7:0] (LSB) Value of M 00000000 00000000 0 … … … 00000000 11111101 253 (default) … … … 11111111 11111111 65,535 PLL numerator MSB. This value is concatenated with N[7:0] to make up a 16-bit number. PLL numerator LSB. This value is concatenated with N[15:8] to make up a 16-bit number. N[15:8] (MSB) N[7:0] (LSB) Value of N 00000000 00000000 0 … … … 00000000 00001100 12 (default) … … … 11111111 11111111 65,535 PLL integer setting. Setting Value of R 0010 2 (default) 0011 3 0100 4 0101 5 0110 6 0111 7 1000 8 PLL input clock divider. Setting Value of X 00 1 (default) 01 2 10 3 11 4 Type of PLL. When set to integer mode, the values of M and N are ignored. 0 = integer (default). 1 = fractional. PLL lock. This read-only bit is flagged when the PLL has finished locking. 0 = PLL unlocked (default). 1 = PLL locked. PLL enable. 0 = PLL disabled (default). 1 = PLL enabled. Rev. C | Page 53 of 92 ADAU1761 R2: Digital Microphone/Jack Detection Control, 16,392 (0x4008) Bit 7 Bit 6 JDDB[1:0] Bit 5 Bit 4 JDFUNC[1:0] Bit 3 Bit 2 Reserved Bit 1 Bit 0 JDPOL Table 36. Digital Microphone/Jack Detection Control Register Bits [7:6] Bit Name JDDB[1:0] [5:4] JDFUNC[1:0] 0 JDPOL Description Jack detect debounce time. Setting Debounce Time 00 5 ms (default) 01 10 ms 10 20 ms 11 40 ms JACKDET/MICIN pin function. Enables or disables the jack detect function or configures the pin for a digital microphone input. Setting Pin Function 00 Jack detect off (default) 01 Jack detect on 10 Digital microphone input 11 Reserved Jack detect polarity. Detects high or low signal. 0 = detect high signal (default). 1 = detect low signal. R3: Record Power Management, 16,393 (0x4009) This register manages the power consumption for the record path. In particular, the current distribution for the mixer boosts, ADCs, record path mixers, and PGAs can be set to one of four modes. These settings are normal operation, power saving mode, enhanced performance mode, and extreme power saving mode. Each of these modes draws current from a central bias. Enhanced performance mode offers the highest performance with the trade-off of higher power consumption. Bit 7 Reserved Bit 6 Bit 5 MXBIAS[1:0] Bit 4 Bit 3 ADCBIAS[1:0] Bit 2 Bit 1 RBIAS[1:0] Bit 0 Reserved Table 37. Record Power Management Register Bits [6:5] Bit Name MXBIAS[1:0] [4:3] ADCBIAS[1:0] [2:1] RBIAS[1:0] Description Mixer amplifier bias boost. Sets the boost level for the bias current of the record path mixers. In some cases, the boost level enhances the THD + N performance. Setting Boost Level 00 Normal operation (default) 01 Boost Level 1 10 Boost Level 2 11 Boost Level 3 ADC bias control. Sets the bias current for the ADCs based on the mode of operation selected. Setting ADC Bias Control 00 Normal operation (default) 01 Extreme power saving 10 Enhanced performance Power saving 11 Record path bias control. Sets the bias current for the PGAs and mixers in the record path. Setting Record Path Bias Control 00 Normal operation (default) 01 Reserved 10 Enhanced performance 11 Power saving Rev. C | Page 54 of 92 ADAU1761 R4: Record Mixer Left (Mixer 1) Control 0, 16,394 (0x400A) This register controls the gain of single-ended inputs for the left channel record path. The left channel record mixer is referred to as Mixer 1. Bit 7 Reserved Bit 6 Bit 5 LINPG[2:0] Bit 4 Bit 3 Bit 2 LINNG[2:0] Table 38. Record Mixer Left (Mixer 1) Control 0 Register Bits [6:4] Bit Name LINPG[2:0] [3:1] LINNG[2:0] 0 MX1EN Description Gain for a left channel single-ended input from the LINP pin, input to Mixer 1. Setting Gain 000 Mute (default) 001 −12 dB 010 −9 dB 011 −6 dB 100 −3 dB 101 0 dB 110 3 dB 111 6 dB Gain for a left channel single-ended input from the LINN pin, input to Mixer 1. Setting Gain 000 Mute (default) 001 −12 dB 010 −9 dB 011 −6 dB 100 −3 dB 101 0 dB 110 3 dB 111 6 dB Left channel mixer enable in the record path. Referred to as Mixer 1. 0 = mixer disabled (default). 1 = mixer enabled. Rev. C | Page 55 of 92 Bit 1 Bit 0 MX1EN ADAU1761 R5: Record Mixer Left (Mixer 1) Control 1, 16,395 (0x400B) This register controls the gain boost of the left channel differential PGA input and the gain for the left channel auxiliary input in the record path. The left channel record mixer is referred to as Mixer 1. Bit 7 Bit 6 Reserved Bit 5 Bit 4 Bit 3 LDBOOST[1:0] Bit 2 Bit 1 MX1AUXG[2:0] Bit 0 Table 39. Record Mixer Left (Mixer 1) Control 1 Register Bits [4:3] Bit Name LDBOOST[1:0] [2:0] MX1AUXG[2:0] Description Left channel differential PGA input gain boost, input to Mixer 1. The left differential input uses the LINP (positive signal) and LINN (negative signal) pins. Setting Gain Boost 00 Mute (default) 01 0 dB 10 20 dB 11 Reserved Left single-ended auxiliary input gain from the LAUX pin in the record path, input to Mixer 1. Setting Auxiliary Input Gain 000 Mute (default) 001 −12 dB 010 −9 dB 011 −6 dB 100 −3 dB 101 0 dB 110 3 dB 111 6 dB Rev. C | Page 56 of 92 ADAU1761 R6: Record Mixer Right (Mixer 2) Control 0, 16,396 (0x400C) This register controls the gain of single-ended inputs for the right channel record path. The right channel record mixer is referred to as Mixer 2. Bit 7 Reserved Bit 6 Bit 5 RINPG[2:0] Bit 4 Bit 3 Bit 2 RINNG[2:0] Bit 1 Table 40. Record Mixer Right (Mixer 2) Control 0 Register Bits [6:4] Bit Name RINPG[2:0] [3:1] RINNG[2:0] 0 MX2EN Description Gain for a right channel single-ended input from the RINP pin, input to Mixer 2. Setting Gain 000 Mute (default) 001 −12 dB 010 −9 dB 011 −6 dB 100 −3 dB 101 0 dB 110 3 dB 111 6 dB Gain for a right channel single-ended input from the RINN pin, input to Mixer 2. Setting Gain 000 Mute (default) 001 −12 dB 010 −9 dB 011 −6 dB 100 −3 dB 101 0 dB 110 3 dB 111 6 dB Right channel mixer enable in the record path. Referred to as Mixer 2. 0 = mixer disabled (default). 1 = mixer enabled. Rev. C | Page 57 of 92 Bit 0 MX2EN ADAU1761 R7: Record Mixer Right (Mixer 2) Control 1, 16,397 (0x400D) This register controls the gain boost of the right channel differential PGA input and the gain for the right channel auxiliary input in the record path. The right channel record mixer is referred to as Mixer 2. Bit 7 Bit 6 Reserved Bit 5 Bit 4 Bit 3 RDBOOST[1:0] Bit 2 Bit 1 MX2AUXG[2:0] Bit 0 Table 41. Record Mixer Right (Mixer 2) Control 1 Register Bits [4:3] Bit Name RDBOOST[1:0] [2:0] MX2AUXG[2:0] Description Right channel differential PGA input gain boost, input to Mixer 2. The right differential input uses the RINP (positive signal) and RINN (negative signal) pins. Setting Gain Boost 00 Mute (default) 01 0 dB 10 20 dB 11 Reserved Right single-ended auxiliary input gain from the RAUX pin in the record path, input to Mixer 2. Setting Auxiliary Input Gain 000 Mute (default) 001 −12 dB 010 −9 dB 011 −6 dB 100 −3 dB 101 0 dB 110 3 dB 111 6 dB R8: Left Differential Input Volume Control, 16,398 (0x400E) This register enables the differential path and sets the volume control for the left differential PGA input. Bit 7 Bit 6 Bit 5 Bit 4 LDVOL[5:0] Bit 3 Bit 2 Bit 1 LDMUTE Bit 0 LDEN Table 42. Left Differential Input Volume Control Register Bits [7:2] Bit Name LDVOL[5:0] 1 LDMUTE 0 LDEN Description Left channel differential PGA input volume control. The left differential input uses the LINP (positive signal) and LINN (negative signal) pins. Each step corresponds to a 0.75 dB increase in gain. See Table 92 for a complete list of the volume settings. Setting Volume 000000 −12 dB (default) 000001 −11.25 dB … … 010000 0 dB … … 111110 34.5 dB 111111 35.25 dB Left differential input mute control. 0 = mute (default). 1 = unmute. Left differential PGA enable. When enabled, the LINP and LINN pins are used as a full differential pair. When disabled, these two pins are configured as two single-ended inputs with the signals routed around the PGA. 0 = disabled (default). 1 = enabled. Rev. C | Page 58 of 92 ADAU1761 R9: Right Differential Input Volume Control, 16,399 (0x400F) This register enables the differential path and sets the volume control for the right differential PGA input. Bit 7 Bit 6 Bit 5 Bit 4 RDVOL[5:0] Bit 3 Bit 2 Bit 1 RDMUTE Bit 0 RDEN Table 43. Right Differential Input Volume Control Register Bits [7:2] Bit Name RDVOL[5:0] 1 RDMUTE 0 RDEN Description Right channel differential PGA input volume control. The right differential input uses the RINP (positive signal) and RINN (negative signal) pins. Each step corresponds to a 0.75 dB increase in gain. See Table 92 for a complete list of the volume settings. Setting Volume 000000 −12 dB (default) 000001 −11.25 dB … … 010000 0 dB … … 111110 34.5 dB 111111 35.25 dB Right differential input mute control. 0 = mute (default). 1 = unmute. Right differential PGA enable. When enabled, the RINP and RINN pins are used as a full differential pair. When disabled, these two pins are configured as two single-ended inputs with the signals routed around the PGA. 0 = disabled (default). 1 = enabled. R10: Record Microphone Bias Control, 16,400 (0x4010) This register controls the MICBIAS pin settings for biasing electret type analog microphones. Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 MPERF Bit 2 MBI Bit 1 Reserved Bit 0 MBIEN Table 44. Record Microphone Bias Control Register Bits 3 Bit Name MPERF 2 MBI 0 MBIEN Description Microphone bias is enabled for high performance or normal operation. High performance operation sources more current to the microphone. 0 = normal operation (default). 1 = high performance. Microphone voltage bias as a fraction of AVDD. 0 = 0.90 × AVDD (default). 1 = 0.65 × AVDD. Enables the MICBIAS output. 0 = disabled (default). 1 = enabled. Rev. C | Page 59 of 92 ADAU1761 R11: ALC Control 0, 16,401 (0x4011) Bit 7 Bit 6 PGASLEW[1:0] Bit 5 Bit 4 ALCMAX[2:0] Bit 3 Bit 2 Bit 1 ALCSEL[2:0] Bit 0 Table 45. ALC Control 0 Register Bits [7:6] Bit Name PGASLEW[1:0] [5:3] ALCMAX[2:0] [2:0] ALCSEL[2:0] Description PGA volume slew time when the ALC is off. The slew time is the period of time that a volume increase or decrease takes to ramp up or ramp down to the target volume set in Register R8 (left differential input volume control) and Register R9 (right differential input volume control). Setting Slew Time 00 24 ms (default) 01 48 ms 10 96 ms 11 Off The maximum ALC gain sets a limit to the amount of gain that the ALC can provide to the input signal. This protects small signals from excessive amplification. Setting Maximum ALC Gain 000 −12 dB (default) 001 −6 dB 010 0 dB 011 6 dB 100 12 dB 101 18 dB 110 24 dB 111 30 dB ALC select. These bits set the channels that are controlled by the ALC. When set to right only, the ALC responds only to the right channel input and controls the gain of the right PGA amplifier only. When set to left only, the ALC responds only to the left channel input and controls the gain of the left PGA amplifier only. When set to stereo, the ALC responds to the greater of the left or right channel and controls the gain of both the left and right PGA amplifiers. DSP control allows the PGA gain to be set within the DSP or from external GPIO inputs. These bits must be off if manual control of the volume is desired. Setting Channels 000 Off (default) 001 Right only 010 Left only 011 Stereo 100 DSP control 101 Reserved 110 Reserved 111 Reserved Rev. C | Page 60 of 92 ADAU1761 R12: ALC Control 1, 16,402 (0x4012) Bit 7 Bit 6 Bit 5 ALCHOLD[3:0] Bit 4 Bit 3 Bit 2 Bit 1 ALCTARG[3:0] Bit 0 Table 46. ALC Control 1 Register Bits [7:4] Bit Name ALCHOLD[3:0] [3:0] ALCTARG[3:0] Description ALC hold time. The ALC hold time is the amount of time that the ALC waits after a decrease in input level before increasing the gain to achieve the target level. The recommended minimum setting is 21 ms (0011) to prevent distortion of low frequency signals. The hold time doubles with every 1-bit increase. Setting Hold Time 0000 2.67 ms (default) 0001 5.34 ms 0010 10.68 ms 0011 21.36 ms 0100 42.72 ms 0101 85.44 ms 0110 170.88 ms 0111 341.76 ms 1000 683.52 ms 1001 1.367 sec 1010 2.7341 sec 1011 5.4682 sec 1100 10.936 sec 1101 21.873 sec 1110 43.745 sec 1111 87.491 sec ALC target. The ALC target sets the desired ADC input level. The PGA gain is adjusted by the ALC to reach this target level. The recommended target level is between −16 dB and −10 dB to accommodate transients without clipping the ADC. Setting ALC Target 0000 −28.5 dB (default) 0001 −27 dB 0010 −25.5 dB 0011 −24 dB 0100 −22.5 dB 0101 −21 dB −19.5 dB 0110 0111 −18 dB 1000 −16.5 dB 1001 −15 dB 1010 −13.5 dB 1011 −12 dB 1100 −10.5 dB 1101 −9 dB 1110 −7.5 dB 1111 −6 dB Rev. C | Page 61 of 92 ADAU1761 R13: ALC Control 2, 16,403 (0x4013) Bit 7 Bit 6 Bit 5 ALCATCK[3:0] Bit 4 Bit 3 Bit 2 Bit 1 ALCDEC[3:0] Bit 0 Table 47. ALC Control 2 Register Bits [7:4] Bit Name ALCATCK[3:0] [3:0] ALCDEC[3:0] Description ALC attack time. The attack time sets how fast the ALC starts attenuating after an increase in input level above the target. A typical setting for music recording is 384 ms, and a typical setting for voice recording is 24 ms. Setting Attack Time 0000 6 ms (default) 0001 12 ms 0010 24 ms 0011 48 ms 0100 96 ms 0101 192 ms 0110 384 ms 0111 768 ms 1000 1.54 sec 1001 3.07 sec 1010 6.14 sec 1011 12.29 sec 1100 24.58 sec 1101 49.15 sec 1110 98.30 sec 1111 196.61 sec ALC decay time. The decay time sets how fast the ALC increases the PGA gain after a decrease in input level below the target. A typical setting for music recording is 24.58 seconds, and a typical setting for voice recording is 1.54 seconds. Setting Decay Time 0000 24 ms 0001 48 ms 0010 96 ms 0011 192 ms 0100 384 ms 0101 768 ms 0110 1.54 sec 0111 3.07 sec 1000 6.14 sec 1001 12.29 sec 1010 24.58 sec 1011 49.15 sec 1100 98.30 sec 1101 196.61 sec 1110 393.22 sec 1111 786.43 sec Rev. C | Page 62 of 92 ADAU1761 R14: ALC Control 3, 16,404 (0x4014) Bit 7 Bit 6 NGTYP[1:0] Bit 5 NGEN Bit 4 Bit 3 Bit 2 NGTHR[4:0] Bit 1 Bit 0 Table 48. ALC Control 3 Register Bits [7:6] Bit Name NGTYP[1:0] 5 NGEN [4:0] NGTHR[4:0] Description Noise gate type. When the input signal falls below the threshold for 250 ms, the noise gate can hold a constant PGA gain, mute the ADC output, fade the PGA gain to the minimum gain value, or fade then mute. Setting Noise Gate 00 Hold PGA constant (default) 01 Mute ADC output (digital mute) 10 Fade to PGA minimum value (analog fade) 11 Fade then mute (analog fade/digital mute) Noise gate enable. 0 = disabled (default). 1 = enabled. Noise gate threshold. When the input signal falls below the threshold for 250 ms, the noise gate is activated. A 1 LSB increase corresponds to a −1.5 dB change. See Table 93 for a complete list of the threshold settings. Setting Threshold 00000 −76.5 dB (default) 00001 −75 dB … … 11110 −31.5 dB 11111 −30 dB R15: Serial Port Control 0, 16,405 (0x4015) Bit 7 Reserved Bit 6 SPSRS Bit 5 LRMOD Bit 4 BPOL Bit 3 LRPOL Bit 2 Bit 1 CHPF[1:0] Bit 0 MS Table 49. Serial Port Control 0 Register Bits 6 Bit Name SPSRS 5 LRMOD 4 BPOL 3 LRPOL [2:1] CHPF[1:0] 0 MS Description Serial port sampling rate source. 0 = converter rate set in Register R17 (default). 1 = DSP rate set in Register R57. LRCLK mode sets the LRCLK for either a 50% duty cycle or a pulse. The pulse mode should be at least 1 BCLK wide. 0 = 50% duty cycle (default). 1 = pulse mode. BCLK polarity sets the BCLK edge that triggers a change in audio data. This can be set for the falling or rising edge of the BCLK. 0 = falling edge (default). 1 = rising edge. LRCLK polarity sets the LRCLK edge that triggers the beginning of the left channel audio frame. This can be set for the falling or rising edge of the LRCLK. 0 = falling edge (default). 1 = rising edge. Channels per frame sets the number of channels per LRCLK frame. Setting Channels per LRCLK Frame 00 Stereo (default) 01 TDM 4 10 TDM 8 11 Reserved Serial data port bus mode. Both LRCLK and BCLK are master of the serial port when set in master mode and are serial port slave in slave mode. 0 = slave mode (default). 1 = master mode. Rev. C | Page 63 of 92 ADAU1761 R16: Serial Port Control 1, 16,406 (0x4016) Bit 7 Bit 6 BPF[2:0] Bit 5 Bit 4 ADTDM Bit 3 DATDM Table 50. Serial Port Control 1 Register Bits [7:5] Bit Name BPF[2:0] 4 ADTDM 3 DATDM 2 MSBP [1:0] LRDEL[1:0] Description Number of bit clock cycles per LRCLK audio frame. Setting Bit Clock Cycles 000 64 (default) 001 Reserved 010 48 011 128 100 256 Reserved 101 110 Reserved 111 Reserved ADC serial audio data channel position in TDM mode. 0 = left first (default). 1 = right first. DAC serial audio data channel position in TDM mode. 0 = left first (default). 1 = right first. MSB position in the LRCLK frame. 0 = MSB first (default). 1 = LSB first. Data delay from LRCLK edge (in BCLK units). Setting Delay (Bit Clock Cycles) 00 1 (default) 01 0 10 8 11 16 Rev. C | Page 64 of 92 Bit 2 MSBP Bit 1 Bit 0 LRDEL[1:0] ADAU1761 R17: Converter Control 0, 16,407 (0x4017) Bit 7 Reserved Bit 6 Bit 5 DAPAIR[1:0] Bit 4 DAOSR Bit 3 ADOSR Bit 2 Bit 1 CONVSR[2:0] Bit 0 Table 51. Converter Control 0 Register Bits [6:5] Bit Name DAPAIR[1:0] 4 DAOSR 3 ADOSR [2:0] CONVSR[2:0] Description On-chip DAC serial data selection in TDM 4 or TDM 8 mode. Setting Pair 00 First pair (default) 01 Second pair 10 Third pair 11 Fourth pair DAC oversampling ratio. This bit cannot be set for 64× when CONVSR[2:0] is set to 96 kHz. 0 = 128× (default). 1 = 64×. ADC oversampling ratio. This bit cannot be set for 64× when CONVSR[2:0] is set to 96 kHz. 0 = 128× (default). 1 = 64×. Converter sampling rate. The ADCs and DACs operate at the sampling rate set in this register. The converter rate selected is a ratio of the base sampling rate, fS. The base sampling rate is determined by the operating frequency of the core clock. Setting Sampling Rate Base Sampling Rate (fS = 48 kHz) 000 fS 48 kHz, base (default) 001 fS/6 8 kHz 010 fS/4 12 kHz 011 fS/3 16 kHz 100 fS/2 24 kHz 101 fS/1.5 32 kHz 110 fS/0.5 96 kHz 111 Reserved R18: Converter Control 1, 16,408 (0x4018) Bit 7 Bit 6 Bit 5 Bit 4 Reserved Bit 3 Table 52. Converter Control 1 Register Bits [1:0] Bit Name ADPAIR[1:0] Description On-chip ADC serial data selection in TDM 4 or TDM 8 mode. Setting Pair 00 First pair (default) 01 Second pair 10 Third pair 11 Fourth pair Rev. C | Page 65 of 92 Bit 2 Bit 1 Bit 0 ADPAIR[1:0] ADAU1761 R19: ADC Control, 16,409 (0x4019) Bit 7 Reserved Bit 6 ADCPOL Bit 5 HPF Bit 4 DMPOL Bit 3 DMSW Bit 2 INSEL Bit 1 Bit 0 ADCEN[1:0] Table 53. ADC Control Register Bits 6 Bit Name ADCPOL 5 HPF 4 DMPOL 3 DMSW 2 INSEL [1:0] ADCEN[1:0] Description Invert input polarity. 0 = normal (default). 1 = inverted. ADC high-pass filter select. At 48 kHz, f3dB = 2 Hz. 0 = off (default). 1 = on. Digital microphone data polarity swap. 0 = invert polarity. 1 = normal (default). Digital microphone channel swap. Normal operation sends the left channel on the rising edge of the clock and the right channel on the falling edge of the clock. 0 = normal (default). 1 = swap left and right channels. Digital microphone input select. When asserted, the on-chip ADCs are off, BCLK is master at 128 × fS, and ADC_SDATA is expected to have left and right channels interleaved. 0 = digital microphone inputs off, ADCs enabled (default). 1 = digital microphone inputs enabled, ADCs off. ADC enable. Setting ADCs Enabled 00 Both off (default) 01 Left on 10 Right on 11 Both on R20: Left Input Digital Volume, 16,410 (0x401A) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 LADVOL[7:0] Bit 2 Bit 1 Bit 0 Table 54. Left Input Digital Volume Register Bits [7:0] Bit Name LADVOL[7:0] Description Controls the digital volume attenuation for left channel inputs from either the left ADC or the left digital microphone input. Each bit corresponds to a 0.375 dB step with slewing between settings. See Table 94 for a complete list of the volume settings. Setting Volume Attenuation 00000000 0 dB (default) 00000001 −0.375 dB 00000010 −0.75 dB … … 11111110 −95.25 dB 11111111 −95.625 dB Rev. C | Page 66 of 92 ADAU1761 R21: Right Input Digital Volume, 16,411 (0x401B) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 RADVOL[7:0] Bit 2 Bit 1 Bit 0 Table 55. Right Input Digital Volume Register Bits [7:0] Bit Name RADVOL[7:0] Description Controls the digital volume attenuation for right channel inputs from either the right ADC or the right digital microphone input. Each bit corresponds to a 0.375 dB step with slewing between settings. See Table 94 for a complete list of the volume settings. Setting Volume Attenuation 00000000 0 dB (default) 00000001 −0.375 dB 00000010 −0.75 dB … … 11111110 −95.25 dB 11111111 −95.625 dB R22: Playback Mixer Left (Mixer 3) Control 0, 16,412 (0x401C) Bit 7 Reserved Bit 6 MX3RM Bit 5 MX3LM Bit 4 Bit 3 Bit 2 MX3AUXG[3:0] Bit 1 Bit 0 MX3EN Table 56. Playback Mixer Left (Mixer 3) Control 0 Register Bits 6 Bit Name MX3RM 5 MX3LM [4:1] MX3AUXG[3:0] 0 MX3EN Description Mixer input mute. Mutes the right DAC input to the left channel playback mixer (Mixer 3). 0 = muted (default). 1 = unmuted. Mixer input mute. Mutes the left DAC input to the left channel playback mixer (Mixer 3). 0 = muted (default). 1 = unmuted. Mixer input gain. Controls the left channel auxiliary input gain to the left channel playback mixer (Mixer 3). Setting Gain 0000 Mute (default) 0001 −15 dB 0010 −12 dB 0011 −9 dB 0100 −6 dB 0101 −3 dB 0110 0 dB 0111 3 dB 1000 6 dB Mixer 3 enable. 0 = disabled (default). 1 = enabled. Rev. C | Page 67 of 92 ADAU1761 R23: Playback Mixer Left (Mixer 3) Control 1, 16,413 (0x401D) Bit 7 Bit 6 Bit 5 MX3G2[3:0] Bit 4 Bit 3 Bit 2 Bit 1 MX3G1[3:0] Bit 0 Table 57. Playback Mixer Left (Mixer 3) Control 1 Register Bits [7:4] Bit Name MX3G2[3:0] [3:0] MX3G1[3:0] Description Bypass gain control. The signal from the right channel record mixer (Mixer 2) bypasses the converters and gain can be applied before the left playback mixer (Mixer 3). Setting Gain 0000 Mute (default) 0001 −15 dB 0010 −12 dB 0011 −9 dB 0100 −6 dB 0101 −3 dB 0110 0 dB 0111 3 dB 1000 6 dB Bypass gain control. The signal from the left channel record mixer (Mixer 1) bypasses the converters and gain can be applied before the left playback mixer (Mixer 3). Setting Gain 0000 Mute (default) 0001 −15 dB 0010 −12 dB 0011 −9 dB 0100 −6 dB 0101 −3 dB 0110 0 dB 0111 3 dB 1000 6 dB Rev. C | Page 68 of 92 ADAU1761 R24: Playback Mixer Right (Mixer 4) Control 0, 16,414 (0x401E) Bit 7 Reserved Bit 6 MX4RM Bit 5 MX4LM Bit 4 Bit 3 Bit 2 MX4AUXG[3:0] Bit 1 Bit 0 MX4EN Table 58. Playback Mixer Right (Mixer 4) Control 0 Register Bits 6 Bit Name MX4RM 5 MX4LM [4:1] MX4AUXG[3:0] 0 MX4EN Description Mixer input mute. Mutes the right DAC input to the right channel playback mixer (Mixer 4). 0 = muted (default). 1 = unmuted. Mixer input mute. Mutes the left DAC input to the right channel playback mixer (Mixer 4). 0 = muted (default). 1 = unmuted. Mixer input gain. Controls the right channel auxiliary input gain to the right channel playback mixer (Mixer 4). Setting Gain 0000 Mute (default) 0001 −15 dB 0010 −12 dB 0011 −9 dB 0100 −6 dB 0101 −3 dB 0110 0 dB 0111 3 dB 1000 6 dB Mixer 4 enable. 0 = disabled (default). 1 = enabled. Rev. C | Page 69 of 92 ADAU1761 R25: Playback Mixer Right (Mixer 4) Control 1, 16,415 (0x401F) Bit 7 Bit 6 Bit 5 MX4G2[3:0] Bit 4 Bit 3 Bit 2 Bit 1 MX4G1[3:0] Bit 0 Table 59. Playback Mixer Right (Mixer 4) Control 1 Register Bits [7:4] Bit Name MX4G2[3:0] [3:0] MX4G1[3:0] Description Bypass gain control. The signal from the right channel record mixer (Mixer 2) bypasses the converters and gain can be applied before the right playback mixer (Mixer 4). Setting Gain 0000 Mute (default) 0001 −15 dB 0010 −12 dB 0011 −9 dB 0100 −6 dB 0101 −3 dB 0110 0 dB 0111 3 dB 1000 6 dB Bypass gain control. The signal from the left channel record mixer (Mixer 1) bypasses the converters and gain can be applied before the right playback mixer (Mixer 4). Setting Gain 0000 Mute (default) 0001 −15 dB 0010 −12 dB 0011 −9 dB 0100 −6 dB 0101 −3 dB 0110 0 dB 0111 3 dB 1000 6 dB Rev. C | Page 70 of 92 ADAU1761 R26: Playback L/R Mixer Left (Mixer 5) Line Output Control, 16,416 (0x4020) Bit 7 Bit 6 Reserved Bit 5 Bit 4 Bit 3 MX5G4[1:0] Bit 2 Bit 1 MX5G3[1:0] Bit 0 MX5EN Table 60. Playback L/R Mixer Left (Mixer 5) Line Output Control Register Bits [4:3] Bit Name MX5G4[1:0] [2:1] MX5G3[1:0] 0 MX5EN Description Mixer input gain boost. The signal from the right channel playback mixer (Mixer 4) can be enabled and boosted in the playback L/R mixer left (Mixer 5). Setting Gain Boost 00 Mute (default) 01 0 dB output (−6 dB gain on each of the two inputs) 10 6 dB output (0 dB gain on each of the two inputs) 11 Reserved Mixer input gain boost. The signal from the left channel playback mixer (Mixer 3) can be enabled and boosted in the playback L/R mixer left (Mixer 5). Setting Gain Boost 00 Mute (default) 01 0 dB output (−6 dB gain on each of the two inputs) 10 6 dB output (0 dB gain on each of the two inputs) 11 Reserved Mixer 5 enable. 0 = disabled (default). 1 = enabled. R27: Playback L/R Mixer Right (Mixer 6) Line Output Control, 16,417 (0x4021) Bit 7 Bit 6 Reserved Bit 5 Bit 4 Bit 3 MX6G4[1:0] Bit 2 Bit 1 MX6G3[1:0] Bit 0 MX6EN Table 61. Playback L/R Mixer Right (Mixer 6) Line Output Control Register Bits [4:3] Bit Name MX6G4[1:0] [2:1] MX6G3[1:0] 0 MX6EN Description Mixer input gain boost. The signal from the right channel playback mixer (Mixer 4) can be enabled and boosted in the playback L/R mixer right (Mixer 6). Setting Gain Boost 00 Mute (default) 01 0 dB output (−6 dB gain on each of the two inputs) 10 6 dB output (0 dB gain on each of the two inputs) 11 Reserved Mixer input gain boost. The signal from the left channel playback mixer (Mixer 3) can be enabled and boosted in the playback L/R mixer right (Mixer 6). Setting Gain Boost 00 Mute (default) 01 0 dB output (−6 dB gain on each of the two inputs) 10 6 dB output (0 dB gain on each of the two inputs) 11 Reserved Mixer 6 enable. 0 = disabled (default). 1 = enabled. Rev. C | Page 71 of 92 ADAU1761 R28: Playback L/R Mixer Mono Output (Mixer 7) Control, 16,418 (0x4022) Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 Bit 2 Bit 1 MX7[1:0] Bit 0 MX7EN Table 62. Playback L/R Mixer Mono Output (Mixer 7) Control Register Bits [2:1] Bit Name MX7[1:0] 0 MX7EN Description L/R mono playback mixer (Mixer 7). Mixes the left and right playback mixers (Mixer 3 and Mixer 4) with either a 0 dB or 6 dB gain boost. Additionally, this mixer can operate as a common-mode output, which is used as the virtual ground in a capless headphone configuration. Setting Gain Boost 00 Common-mode output (default) 01 0 dB output (−6 dB gain on each of the two inputs) 10 6 dB output (0 dB gain on each of the two inputs) 11 Reserved Mixer 7 enable. 0 = disabled (default). 1 = enabled. R29: Playback Headphone Left Volume Control, 16,419 (0x4023) Bit 7 Bit 6 Bit 5 Bit 4 LHPVOL[5:0] Bit 3 Bit 2 Bit 1 LHPM Bit 0 HPEN Table 63. Playback Headphone Left Volume Control Register Bits [7:2] Bit Name LHPVOL[5:0] 1 LHPM 0 HPEN Description Headphone volume control for left channel, LHP output. Each 1-bit step corresponds to a 1 dB increase in volume. See Table 95 for a complete list of the volume settings. Setting Volume 000000 −57 dB (default) … … 111001 0 dB … … 6 dB 111111 Headphone mute for left channel, LHP output (active low). 0 = mute. 1 = unmute (default). Headphone volume control enable. Logical OR with the HPMODE bit in Register R30. If either the HPEN bit or the HPMODE bit is set to 1, the headphone output is enabled. 0 = disabled (default). 1 = enabled. Rev. C | Page 72 of 92 ADAU1761 R30: Playback Headphone Right Volume Control, 16,420 (0x4024) Bit 7 Bit 6 Bit 5 Bit 4 RHPVOL[5:0] Bit 3 Bit 2 Bit 1 RHPM Bit 0 HPMODE Table 64. Playback Headphone Right Volume Control Register Bits [7:2] Bit Name RHPVOL[5:0] 1 RHPM 0 HPMODE Description Headphone volume control for right channel, RHP output. Each 1-bit step corresponds to a 1 dB increase in volume. See Table 95 for a complete list of the volume settings. Setting Volume 000000 −57 dB (default) … … 111001 0 dB … … 111111 6 dB Headphone mute for right channel, RHP output (active low). 0 = mute. 1 = unmute (default). RHP and LHP output mode. These pins can be configured for either line outputs or headphone outputs. Logical OR with the HPEN bit in Register R29. If either the HPMODE bit or the HPEN bit is set to 1, the headphone output is enabled. 0 = enable line output (default). 1 = enable headphone output. R31: Playback Line Output Left Volume Control, 16,421 (0x4025) Bit 7 Bit 6 Bit 5 Bit 4 LOUTVOL[5:0] Bit 3 Bit 2 Bit 1 LOUTM Bit 0 LOMODE Table 65. Playback Line Output Left Volume Control Register Bits [7:2] Bit Name LOUTVOL[5:0] 1 LOUTM 0 LOMODE Description Line output volume control for left channel, LOUTN and LOUTP outputs. Each 1-bit step corresponds to a 1 dB increase in volume. See Table 95 for a complete list of the volume settings. Setting Volume 000000 −57 dB (default) … … 111001 0 dB … … 111111 6 dB Line output mute for left channel, LOUTN and LOUTP outputs (active low). 0 = mute. 1 = unmute (default). Line output mode for left channel, LOUTN and LOUTP outputs. These pins can be configured for either line outputs or headphone outputs. To drive earpiece speakers, set this bit to 1 (headphone output). 0 = line output (default). 1 = headphone output. Rev. C | Page 73 of 92 ADAU1761 R32: Playback Line Output Right Volume Control, 16,422 (0x4026) Bit 7 Bit 6 Bit 5 Bit 4 ROUTVOL[5:0] Bit 3 Bit 2 Bit 1 ROUTM Bit 0 ROMODE Table 66. Playback Line Output Right Volume Control Register Bits [7:2] Bit Name ROUTVOL[5:0] 1 ROUTM 0 ROMODE Description Line output volume control for right channel, ROUTN and ROUTP outputs. Each 1-bit step corresponds to a 1 dB increase in volume. See Table 95 for a complete list of the volume settings. Setting Volume 000000 −57 dB (default) … … 111001 0 dB … … 111111 6 dB Line output mute for right channel, ROUTN and ROUTP outputs (active low). 0 = mute. 1 = unmute (default). Line output mode for right channel, ROUTN and ROUTP outputs. These pins can be configured for either line outputs or headphone outputs. To drive earpiece speakers, set this bit to 1 (headphone output). 0 = line output (default). 1 = headphone output. R33: Playback Mono Output Control, 16,423 (0x4027) Bit 7 Bit 6 Bit 5 Bit 4 MONOVOL[5:0] Bit 3 Bit 2 Bit 1 MONOM Bit 0 MOMODE Table 67. Playback Mono Output Control Register Bits [7:2] Bit Name MONOVOL[5:0] 1 MONOM 0 MOMODE Description Mono output volume control. Each 1-bit step corresponds to a 1 dB increase in volume. If MX7[1:0] in Register R28 is set for common-mode output, volume control is disabled. See Table 95 for a complete list of the volume settings. Setting Volume 000000 −57 dB (default) … … 111001 0 dB … … 111111 6 dB Mono output mute (active low). 0 = mute. 1 = unmute (default). Headphone mode enable. If MX7[1:0] in Register R28 is set for common-mode output for a capless headphone configuration, this bit should be set to 1 ( headphone output). 0 = line output (default). 1 = headphone output. Rev. C | Page 74 of 92 ADAU1761 R34: Playback Pop/Click Suppression, 16,424 (0x4028) Bit 7 Bit 6 Reserved Bit 5 Bit 4 POPMODE Bit 3 POPLESS Bit 2 Bit 1 ASLEW[1:0] Bit 0 Reserved Table 68. Playback Pop/Click Suppression Register Bits 4 Bit Name POPMODE 3 POPLESS [2:1] ASLEW[1:0] Description Pop suppression circuit power saving mode. The pop suppression circuits charge faster in normal operation; however, after they are charged, they can be put into low power operation. 0 = normal (default). 1 = low power. Pop suppression disable. The pop suppression circuits are enabled by default. They can be disabled to save power; however, disabling the circuits increases the risk of pops and clicks. 0 = enabled (default). 1 = disabled. Analog volume slew rate for playback volume controls. Setting Slew Rate 00 21.25 ms (default) 01 42.5 ms 10 85 ms 11 Off R35: Playback Power Management, 16,425 (0x4029) Bit 7 Bit 6 HPBIAS[1:0] Bit 5 Bit 4 DACBIAS[1:0] Bit 3 Bit 2 PBIAS[1:0] Table 69. Playback Power Management Register Bits [7:6] Bit Name HPBIAS[1:0] [5:4] DACBIAS[1:0] [3:2] PBIAS[1:0] 1 PREN 0 PLEN Description Headphone bias control. Setting Headphone Bias Control 00 Normal operation (default) 01 Extreme power saving 10 Enhanced performance 11 Power saving DAC bias control. Setting DAC Bias Control 00 Normal operation (default) 01 Extreme power saving 10 Enhanced performance 11 Power saving Playback path channel bias control. Setting Playback Path Bias Control 00 Normal operation (default) 01 Reserved 10 Enhanced performance 11 Power saving Playback right channel enable. 0 = disabled (default). 1 = enabled. Playback left channel enable. 0 = disabled (default). 1 = enabled. Rev. C | Page 75 of 92 Bit 1 PREN Bit 0 PLEN ADAU1761 R36: DAC Control 0, 16,426 (0x402A) Bit 7 Bit 6 DACMONO[1:0] Bit 5 DACPOL Bit 4 Bit 3 Reserved Bit 2 DEMPH Bit 1 Bit 0 DACEN[1:0] Table 70. DAC Control 0 Register Bits [7:6] Bit Name DACMONO[1:0] 5 DACPOL 2 DEMPH [1:0] DACEN[1:0] Description DAC mono mode. The DAC channels can be set to mono mode within the DAC and output on the left channel, the right channel, or both channels. Setting Mono Mode 00 Stereo (default) 01 Left channel in mono mode 10 Right channel in mono mode 11 Both channels in mono mode Invert input polarity of the DACs. 0 = normal (default). 1 = inverted. DAC de-emphasis filter enable. The de-emphasis filter is designed for use with a sampling rate of 44.1 kHz only. 0 = disabled (default). 1 = enabled. DAC enable. Setting DACs Enabled 00 Both off (default) 01 Left on 10 Right on 11 Both on R37: DAC Control 1, 16,427 (0x402B) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 LDAVOL[7:0] Bit 2 Bit 1 Bit 0 Table 71. DAC Control 1 Register Bits [7:0] Bit Name LDAVOL[7:0] Description Controls the digital volume attenuation for left channel inputs from the left DAC. Each bit corresponds to a 0.375 dB step with slewing between settings. See Table 94 for a complete list of the volume settings. Setting Volume Attenuation 00000000 0 dB (default) 00000001 −0.375 dB 00000010 −0.75 dB … … 11111110 −95.25 dB 11111111 −95.625 dB Rev. C | Page 76 of 92 ADAU1761 R38: DAC Control 2, 16,428 (0x402C) Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 RDAVOL[7:0] Bit 2 Bit 1 Bit 0 Table 72. DAC Control 2 Register Bits [7:0] Bit Name RDAVOL[7:0] Description Controls the digital volume attenuation for right channel inputs from the right DAC. Each bit corresponds to a 0.375 dB step with slewing between settings. See Table 94 for a complete list of the volume settings. Setting Volume Attenuation 00000000 0 dB (default) 00000001 −0.375 dB 00000010 −0.75 dB … … 11111110 −95.25 dB 11111111 −95.625 dB R39: Serial Port Pad Control, 16,429 (0x402D) The optional pull-up/pull-down resistors are nominally 250 kΩ. When enabled, these pull-up/pull-down resistors set the serial port signals to a defined state when the signal source becomes three-state. Bit 7 Bit 6 ADCSDP[1:0] Bit 5 Bit 4 DACSDP[1:0] Bit 3 Table 73. Serial Port Pad Control Register Bits [7:6] Bit Name ADCSDP[1:0] [5:4] DACSDP[1:0] [3:2] LRCLKP[1:0] [1:0] BCLKP[1:0] Description ADC_SDATA pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down DAC_SDATA pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down LRCLK pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down BCLK pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down Rev. C | Page 77 of 92 Bit 2 LRCLKP[1:0] Bit 1 Bit 0 BCLKP[1:0] ADAU1761 R40: Control Port Pad Control 0, 16,431 (0x402F) The optional pull-up/pull-down resistors are nominally 250 kΩ. When enabled, these pull-up/pull-down resistors set the control port signals to a defined state when the signal source becomes three-state. Bit 7 Bit 6 CDATP[1:0] Bit 5 Bit 4 CLCHP[1:0] Bit 3 Bit 2 SCLP[1:0] Bit 1 Bit 0 SDAP[1:0] Table 74. Control Port Pad Control 0 Register Bits [7:6] Bit Name CDATP[1:0] [5:4] CLCHP[1:0] [3:2] SCLP[1:0] [1:0] SDAP[1:0] Description CDATA pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down CLATCH pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) Pull-down 11 SCL/CCLK pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down SDA/COUT pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved 10 None (default) 11 Pull-down R41: Control Port Pad Control 1, 16,432 (0x4030) With IOVDD set to 3.3 V, the low and high drive strengths of the SDA/COUT pin are approximately 2.0 mA and 4.0 mA, respectively. With IOVDD set to 1.8 V, the low and high drive strengths are approximately 0.8 mA and 1.7 mA, respectively. The high drive strength mode may be useful for generating a stronger ACK pulse in I2C mode, if needed. Bit 7 Bit 6 Bit 5 Bit 4 Reserved Bit 3 Table 75. Control Port Pad Control 1 Register Bits 0 Bit Name SDASTR Description SDA/COUT pin drive strength. 0 = low (default). 1 = high. Rev. C | Page 78 of 92 Bit 2 Bit 1 Bit 0 SDASTR ADAU1761 R42: Jack Detect Pin Control, 16,433 (0x4031) With IOVDD set to 3.3 V, the low and high drive strengths of the JACKDET/MICIN pin are approximately 2.0 mA and 4.0 mA, respectively. With IOVDD set to 1.8 V, the low and high drive strengths are approximately 0.8 mA and 1.7 mA, respectively. The optional pull-up/ pull-down resistors are nominally 250 kΩ. When enabled, these pull-up/pull-down resistors set the input signals to a defined state when the signal source becomes three-state. Bit 7 Bit 6 Reserved Bit 5 JDSTR Bit 4 Reserved Bit 3 Bit 2 JDP[1:0] Bit 1 Bit 0 Reserved Table 76. Jack Detect Pin Control Register Bits 5 Bit Name JDSTR [3:2] JDP[1:0] Description JACKDET/MICIN pin drive strength. 0 = low (default). 1 = high. JACKDET/MICIN pad pull-up/pull-down configuration. Setting Configuration 00 Pull-up 01 Reserved None (default) 10 11 Pull-down R67: Dejitter Control, 16,438 (0x4036) The dejitter control register allows the size of the dejitter window to be set, and also allows all dejitter circuits in the device to be activated or bypassed. Dejitter circuits protect against duplicate samples or skipped samples due to jitter from the serial ports in slave mode. Disabling and reenabling certain subsystems in the device—that is, the ADCs, serial ports, SigmaDSP core, and DACs—during operation can cause the associated dejitter circuits to fail. As a result, audio data fails to be output to the next subsystem in the device. When the serial ports are in master mode, the dejitter circuit can be bypassed by setting the dejitter window to 0. When the serial ports are in slave mode, the dejitter circuit can be reinitialized prior to outputting audio from the device, guaranteeing that audio is output to the next subsystem in the device. Any time that audio must pass through the ADCs, serial port, sound engine/DSP core, or DACs, the dejitter circuit can be bypassed and reset by setting the dejitter window size to 0. In this way, the dejitter circuit can be immediately reactivated, without a wait period, by setting the dejitter window size to the default value of 3. Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 DEJIT[7:0] Table 77. Dejitter Control Register Bits [7:0] Bit Name DEJIT[7:0] Description Dejitter window size. Window Size 00000000 … 00000011 … 00000101 Core Clock Cycles 0 … 3 (default) … 5 Rev. C | Page 79 of 92 Bit 2 Bit 1 Bit 0 ADAU1761 R43 to R47: Cyclic Redundancy Check Registers, 16,576 to 16,580 (0x40C0 to 0x40C4) The cyclic redundancy check (CRC) constantly checks the validity of the program RAM contents. SigmaStudio generates a 32-bit hash sum, which must be written to four consecutive read-only 8-bit register locations. CRC must then be enabled. Every 1024 frames (21 ms at 48 kHz), the IC generates its own 32-bit code and compares it to the one stored in these registers. If the codes do not match, a GPIO pin is set high (CRC flag). This output flag must be enabled using the output CRC error sticky setting in the GPIO pin control register (see Table 79). The 1-bit CRC error flag is reset when the CRCEN bit goes low. For example, a GPIO pin can be connected to an interrupt pin on an external microcontroller, which triggers a rewrite of the corrupted memory. By default, CRC is disabled (the CRCEN bit is set to 0). To enable continuous CRC checking, the user can set the CRCEN bit to 1 after loading a program and sending the correct CRC, which is calculated by SigmaStudio. If an error occurs, it can be cleared by setting the CRCEN bit low, fixing the error (presumably by reloading the program), and then setting the CRCEN bit high again. Address 0x40C0 0x40C1 0x40C2 0x40C3 0x40C4 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 CRC[31:24] CRC[23:16] CRC[15:8] CRC[7:0] Reserved Bit 2 Table 78. Cyclic Redundancy Check Registers Register R43 R44 R45 R46 R47 Address Decimal Hex 16,576 0x40C0 16,577 0x40C1 16,578 0x40C2 16,579 0x40C3 16,580 0x40C4 Bit Name CRC[31:24] CRC[23:16] CRC[15:8] CRC[7:0] CRCEN Description CRC hash sum, Bits[31:24] (read-only register) CRC hash sum, Bits[23:16] (read-only register) CRC hash sum, Bits[15:8] (read-only register) CRC hash sum, Bits[7:0] (read-only register) CRC enable 0 = disabled (default) 1 = enabled Rev. C | Page 80 of 92 Bit 1 Bit 0 CRCEN ADAU1761 R48 to R51: GPIO Pin Control, 16,582 to 16,585 (0x40C6 to 0x40C9) The GPIO pin control register sets the functionality of each GPIO pin as shown in Table 79. The GPIO functions use the same pins as the serial port and must be enabled in the serial data/GPIO pin configuration register (Address 0x40F4). When the GPIO pins are set to I2C/SPI port control mode, the pins are set through writes to memory locations described in Table 32. The value of the optional internal pull-up is nominally 250 kΩ. The output CRC error and output watchdog error settings are sticky, that is, once set, they remain set until the ADAU1761 is reset. Address 0x40C6 0x40C7 0x40C8 0x40C9 Bit 7 Bit 6 Bit 5 Reserved Reserved Reserved Reserved Bit 4 Bit 3 Table 79. GPIO Pin Functionality Bit Settings GPIOx[3:0] Bits 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 GPIO Pin Function Input without debounce (default) Input with debounce (0.3 ms) Input with debounce (0.6 ms) Input with debounce (0.9 ms) Input with debounce (5 ms) Input with debounce (10 ms) Input with debounce (20 ms) Input with debounce (40 ms) Input controlled by I2C/SPI port Output set by I2C/SPI port, with pull-up Output set by I2C/SPI port, no pull-up Output set by DSP core, with pull-up Output set by DSP core, no pull-up Reserved Output CRC error (sticky) Output watchdog error (sticky) Table 80. GPIO Pin Control Registers Register R48 R49 R50 R51 Address Decimal Hex 16,582 0x40C6 16,583 0x40C7 16,584 0x40C8 16,585 0x40C9 Bit Name GPIO0[3:0] GPIO1[3:0] GPIO2[3:0] GPIO3[3:0] Description GPIO 0 pin function (see Table 79) GPIO 1 pin function (see Table 79) GPIO 2 pin function (see Table 79) GPIO 3 pin function (see Table 79) Rev. C | Page 81 of 92 Bit 2 Bit 1 GPIO0[3:0] GPIO1[3:0] GPIO2[3:0] GPIO3[3:0] Bit 0 ADAU1761 R52 to R56: Watchdog Registers, 16,592 to 16,596 (0x40D0 to 0x40D4) A program counter watchdog is used when the core does block processing (which can span several samples). The watchdog flags an error if the program counter reaches a specific 24-bit value (ranging from 0x000000 to 0xFFFFFF) that is set in the register map. This value consists of three consecutive 8-bit register locations. The error flag sends a high signal to one of the GPIO pins. The watchdog function must be enabled by setting the DOGEN bit high in Register R52 (Address 0x40D0). The watchdog error bit (DOGER) is the 1-bit watchdog error flag that can be sent to a GPIO pin, as described in Table 79. This error flag can connect, for example, to an interrupt pin on a microcontroller in the system. The flag is reset when the DOGEN bit goes low. This flag can also be read back over the control port from Register R56 (Address 0x40D4). Address 0x40D0 0x40D1 0x40D2 0x40D3 0x40D4 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Reserved DOG[23:16] DOG[15:8] DOG[7:0] Reserved Bit 2 Bit 1 Bit 0 DOGEN DOGER Table 81. Watchdog Registers Register R52 Address Decimal Hex 16,592 0x40D0 Bit Name DOGEN R53 R54 R55 16,593 16,594 16,595 DOG[23:16] DOG[15:8] DOG[7:0] R56 16,596 0x40D1 0x40D2 0x40D3 0x40D4 DOGER Description Watchdog enable bit. 0 = disabled (default). 1 = enabled. Watchdog value, Bits[23:16] (MSB). Watchdog value, Bits[15:8]. Watchdog value, Bits[7:0]. DOG[23:16] DOG[15:8] 00000000 00000000 … … 11111111 11111111 Watchdog error (read-only bit). 0 = no error (default). 1 = error. DOG[7:0] 00000000 … 11111111 Hex Value 0x000000 (default) … 0xFFFFFF R57: DSP Sampling Rate Setting, 16,619 (0x40EB) Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 Bit 2 Bit 1 DSPSR[3:0] Bit 0 Table 82. DSP Sampling Rate Setting Register Bits [3:0] Bit Name DSPSR[3:0] Description SigmaDSP core sampling rate. The DSP sampling rate is a ratio of the base sampling rate, fS. The base sampling rate is determined by the operating frequency of the core clock. For most applications, the SigmaDSP core sampling rate should equal the converter sampling rate (set using the CONVSR[2:0] bits in Register R17) and the serial port sampling rate (set using the SPSR[2:0] bits in Register R64). Setting Sampling Rate Base Sampling Rate (fS = 48 kHz) 0000 fS/0.5 96 kHz, base 0001 fS 48 kHz (default) 0010 fS/1.5 32 kHz 0011 fS/2 24 kHz 0100 fS/3 16 kHz 0101 fS/4 12 kHz 0110 fS/6 8 kHz 0111 Serial input data rate 1000 Serial output data rate 1111 None Rev. C | Page 82 of 92 ADAU1761 R58: Serial Input Route Control, 16,626 (0x40F2) Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 Bit 2 Bit 1 SINRT[3:0] Bit 0 Table 83. Serial Input Route Control Register Bits [3:0] Bit Name SINRT[3:0] Description Serial data input routing. This register sets the input where the DACs receive serial data. This location can be from the DSP or from any TDM slot on the serial port. Setting Routing 0000 DSP to DACs [L, R] (default) 0001 Serial input [L0, R0] to DACs [L, R] 0010 Reserved 0011 Serial input [L1, R1] to DACs [L, R] 0100 Reserved 0101 Serial input [L2, R2] to DACs [L, R] 0110 Reserved 0111 Serial input [L3, R3] to DACs [L, R] 1000 Reserved 1001 Serial input [R0, L0] to DACs [L, R] 1010 Reserved 1011 Serial input [R1, L1] to DACs [L, R] 1100 Reserved 1101 Serial input [R2, L2] to DACs [L, R] 1110 Reserved 1111 Serial input [R3, L3] to DACs [L, R] R59: Serial Output Route Control, 16,627 (0x40F3) Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 Bit 2 Bit 1 SOUTRT[3:0] Bit 0 Table 84. Serial Output Route Control Register Bits [3:0] Bit Name SOUTRT[3:0] Description Serial data output routing. This register sets the output where the ADCs send serial data. This location can be to the DSP or to any TDM slot on the serial port. Setting Routing 0000 ADCs [L, R] to DSP (default) 0001 ADCs [L, R] to serial output [L0, R0] 0010 Reserved 0011 ADCs [L, R] to serial output [L1, R1] 0100 Reserved 0101 ADCs [L, R] to serial output [L2, R2] 0110 Reserved 0111 ADCs [L, R] to serial output [L3, R3] 1000 Reserved 1001 ADCs [L, R] to serial output [R0, L0] 1010 Reserved 1011 ADCs [L, R] to serial output [R1, L1] 1100 Reserved 1101 ADCs [L, R] to serial output [R2, L2] 1110 Reserved 1111 ADCs [L, R] to serial output [R3, L3] Rev. C | Page 83 of 92 ADAU1761 R60: Serial Data/GPIO Pin Configuration, 16,628 (0x40F4) The serial data/GPIO pin configuration register controls the functionality of the serial data port pins. If the bits in this register are set to 1, these pins are configured as GPIO interfaces to the SigmaDSP. If these bits are set to 0, they are configured as serial data I/O port pins. Bit 7 Bit 6 Bit 5 Reserved Bit 4 Bit 3 LRGP3 Bit 2 BGP2 Bit 1 SDOGP1 Bit 0 SDIGP0 Bit 2 Bit 1 Bit 0 DSPEN Table 85. Serial Data/GPIO Pin Configuration Register Bits 3 Bit Name LRGP3 2 BGP2 1 SDOGP1 0 SDIGP0 Description LRCLK or GPIO3 pin configuration select. 0 = LRCLK enabled (default). 1 = GPIO3 enabled. BCLK or GPIO2 pin configuration select. 0 = BCLK enabled (default). 1 = GPIO2 enabled. ADC_SDATA or GPIO1 pin configuration select. 0 = ADC_SDATA enabled (default). 1 = GPIO1 enabled. DAC_SDATA or GPIO0 pin configuration select. 0 = DAC_SDATA enabled (default). 1 = GPIO0 enabled. R61: DSP Enable, 16,629 (0x40F5) Bit 7 Bit 6 Bit 5 Bit 4 Reserved Bit 3 Table 86. DSP Enable Register Bits 0 Bit Name DSPEN Description Enables the DSP. Set this bit before writing to the parameter RAM and before setting the DSPRUN bit in Register R62 (Address 0x40F6). 0 = DSP disabled (default). 1 = DSP enabled. R62: DSP Run, 16,630 (0x40F6) Bit 7 Bit 6 Bit 5 Bit 4 Reserved Bit 3 Bit 2 Bit 1 Table 87. DSP Run Register Bits 0 Bit Name DSPRUN Description Run the DSP. Set the DSPEN bit in Register R61 (Address 0x40F5) before setting this bit. 0 = DSP off (default). 1 = run the DSP. Rev. C | Page 84 of 92 Bit 0 DSPRUN ADAU1761 R63: DSP Slew Modes, 16,631 (0x40F7) The DSP slew modes register sets the slew source for each output. The slew source can be either the DSP (digital slew) or the codec (analog slew). When these bits are set to Logic 0, the codec provides volume slew according to the ASLEW[1:0] bits in Register R34 (playback pop/click suppression register, Address 0x4028). When these bits are set to Logic 1, the slew is provided and defined by the DSP program, disabling the codec volume slew. Bit 7 Bit 6 Reserved Bit 5 Bit 4 MOSLW Bit 3 ROSLW Bit 2 LOSLW Bit 1 RHPSLW Bit 0 LHPSLW Bit 3 Bit 2 Bit 1 SPSR[2:0] Bit 0 Table 88. DSP Slew Modes Register Bits 4 Bit Name MOSLW 3 ROSLW 2 LOSLW 1 RHPSLW 0 LHPSLW Description Mono output slew generation. 0 = codec (default). 1 = DSP. Line output right slew generation. 0 = codec (default). 1 = DSP. Line output left slew generation. 0 = codec (default). 1 = DSP. Headphone right slew generation. 0 = codec (default). 1 = DSP. Headphone left slew generation. 0 = codec (default). 1 = DSP. R64: Serial Port Sampling Rate, 16,632 (0x40F8) Bit 7 Bit 6 Bit 5 Reserved Bit 4 Table 89. Serial Port Sampling Rate Register Bits [2:0] Bit Name SPSR[2:0] Description Serial port sampling rate. The serial port sampling rate is a ratio of the base sampling rate, fS. The base sampling rate is determined by the operating frequency of the core clock. For most applications, the serial port sampling rate should equal the converter sampling rate (set using the CONVSR[2:0] bits in Register R17) and the DSP sampling rate (set using the DSPSR[3:0] bits in Register R57). Setting Sampling Rate Base Sampling Rate (fS = 48 kHz) 000 fS 48 kHz, base (default) 001 fS/6 8 kHz 010 fS/4 12 kHz 011 fS/3 16 kHz 100 fS/2 24 kHz 101 fS/1.5 32 kHz 110 fS/0.5 96 kHz 111 Reserved Rev. C | Page 85 of 92 ADAU1761 R65: Clock Enable 0, 16,633 (0x40F9) This register disables or enables the digital clock engine for different blocks within the ADAU1761. For maximum power saving, use this register to disable blocks that are not being used. Bit 7 Reserved Bit 6 SLEWPD Bit 5 ALCPD Bit 4 DECPD Bit 3 SOUTPD Bit 2 INTPD Bit 1 SINPD Bit 0 SPPD Table 90. Clock Enable 0 Register Bits 6 Bit Name SLEWPD 5 ALCPD 4 DECPD 3 SOUTPD 2 INTPD 1 SINPD 0 SPPD Description Codec slew digital clock engine enable. When powered down, the analog playback path volume controls are disabled and stay set to their current state. 0 = powered down (default). 1 = enabled. ALC digital clock engine enable. 0 = powered down (default). 1 = enabled. Decimator resync (dejitter) digital clock engine enable. 0 = powered down (default). 1 = enabled. Serial routing outputs digital clock engine enable. 0 = powered down (default). 1 = enabled. Interpolator resync (dejitter) digital clock engine enable. 0 = powered down (default). 1 = enabled. Serial routing inputs digital clock engine enable. 0 = powered down (default). 1 = enabled. Serial port digital clock engine enable. 0 = powered down (default). 1 = enabled. R66: Clock Enable 1, 16,634 (0x40FA) This register enables Digital Clock Generator 0 and Digital Clock Generator 1. Digital Clock Generator 0 generates sample rates for the ADCs, DACs, and DSP. Digital Clock Generator 1 generates BCLK and LRCLK for the serial port when the part is in master mode. For maximum power saving, use this register to disable clocks that are not being used. Bit 7 Bit 6 Bit 5 Bit 4 Reserved Bit 3 Table 91. Clock Enable 1 Register Bits 1 Bit Name CLK1 0 CLK0 Description Digital Clock Generator 1. 0 = off (default). 1 = on. Digital Clock Generator 0. 0 = off (default). 1 = on. Rev. C | Page 86 of 92 Bit 2 Bit 1 CLK1 Bit 0 CLK0 ADAU1761 Table 92. R8 and R9 Volume Settings Binary Value 000000 000001 000010 000011 000100 000101 000110 000111 001000 001001 001010 001011 001100 001101 001110 001111 010000 010001 010010 010011 010100 010101 010110 010111 011000 011001 011010 011011 011100 011101 011110 011111 100000 100001 100010 100011 100100 100101 100110 100111 101000 101001 101010 101011 101100 101101 101110 101111 110000 110001 110010 Volume Setting (dB) −12 −11.25 −10.5 −9.75 −9 −8.25 −7.5 −6.75 −6 −5.25 −4.5 −3.75 −3 −2.25 −1.5 −0.75 0 0.75 1.5 2.25 3 3.75 4.5 5.25 6 6.75 7.5 8.25 9 9.75 10.5 11.25 12 12.75 13.5 14.25 15 15.75 16.5 17.25 18 18.75 19.5 20.25 21 21.75 22.5 23.25 24 24.75 25.5 Binary Value 110011 110100 110101 110110 110111 111000 111001 111010 111011 111100 111101 111110 111111 Volume Setting (dB) 26.25 27 27.75 28.5 29.25 30 30.75 31.5 32.25 33 33.75 34.5 35.25 Table 93. R14 Noise Gate Threshold Binary Value 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 10010 10011 10100 10101 10110 10111 11000 11001 11010 11011 11100 11101 11110 11111 Rev. C | Page 87 of 92 Noise Gate Threshold (dB) −76.5 −75 −73.5 −72 −70.5 −69 −67.5 −66 −64.5 −63 −61.5 −60 −58.5 −57 −55.5 −54 −52.5 −51 −49.5 −48 −46.5 −45 −43.5 −42 −40.5 −39 −37.5 −36 −34.5 −33 −31.5 −30 ADAU1761 Table 94. R20, R21, R37, and R38 Volume Settings Binary Value 00000000 00000001 00000010 00000011 00000100 00000101 00000110 00000111 00001000 00001001 00001010 00001011 00001100 00001101 00001110 00001111 00010000 00010001 00010010 00010011 00010100 00010101 00010110 00010111 00011000 00011001 00011010 00011011 00011100 00011101 00011110 00011111 00100000 00100001 00100010 00100011 00100100 00100101 00100110 00100111 00101000 00101001 00101010 00101011 00101100 00101101 00101110 00101111 Volume Attenuation (dB) 0 −0.375 −0.75 −1.125 −1.5 −1.875 −2.25 −2.625 −3 −3.375 −3.75 −4.125 −4.5 −4.875 −5.25 −5.625 −6 −6.375 −6.75 −7.125 −7.5 −7.875 −8.25 −8.625 −9 −9.375 −9.75 −10.125 −10.5 −10.875 −11.25 −11.625 −12 −12.375 −12.75 −13.125 −13.5 −13.875 −14.25 −14.625 −15 −15.375 −15.75 −16.125 −16.5 −16.875 −17.25 −17.625 Binary Value 00110000 00110001 00110010 00110011 00110100 00110101 00110110 00110111 00111000 00111001 00111010 00111011 00111100 00111101 00111110 00111111 01000000 01000001 01000010 01000011 01000100 01000101 01000110 01000111 01001000 01001001 01001010 01001011 01001100 01001101 01001110 01001111 01010000 01010001 01010010 01010011 01010100 01010101 01010110 01010111 01011000 01011001 01011010 01011011 01011100 01011101 01011110 01011111 Rev. C | Page 88 of 92 Volume Attenuation (dB) −18 −18.375 −18.75 −19.125 −19.5 −19.875 −20.25 −20.625 −21 −21.375 −21.75 −22.125 −22.5 −22.875 −23.25 −23.625 −24 −24.375 −24.75 −25.125 −25.5 −25.875 −26.25 −26.625 −27 −27.375 −27.75 −28.125 −28.5 −28.875 −29.25 −29.625 −30 −30.375 −30.75 −31.125 −31.5 −31.875 −32.25 −32.625 −33 −33.375 −33.75 −34.125 −34.5 −34.875 −35.25 −35.625 ADAU1761 Binary Value 01100000 01100001 01100010 01100011 01100100 01100101 01100110 01100111 01101000 01101001 01101010 01101011 01101100 01101101 01101110 01101111 01110000 01110001 01110010 01110011 01110100 01110101 01110110 01110111 01111000 01111001 01111010 01111011 01111100 01111101 01111110 01111111 10000000 10000001 10000010 10000011 10000100 10000101 10000110 10000111 10001000 10001001 10001010 10001011 10001100 10001101 10001110 10001111 10010000 Volume Attenuation (dB) −36 −36.375 −36.75 −37.125 −37.5 −37.875 −38.25 −38.625 −39 −39.375 −39.75 −40.125 −40.5 −40.875 −41.25 −41.625 −42 −42.375 −42.75 −43.125 −43.5 −43.875 −44.25 −44.625 −45 −45.375 −45.75 −46.125 −46.5 −46.875 −47.25 −47.625 −48 −48.375 −48.75 −49.125 −49.5 −49.875 −50.25 −50.625 −51 −51.375 −51.75 −52.125 −52.5 −52.875 −53.25 −53.625 −54 Binary Value 10010001 10010010 10010011 10010100 10010101 10010110 10010111 10011000 10011001 10011010 10011011 10011100 10011101 10011110 10011111 10100000 10100001 10100010 10100011 10100100 10100101 10100110 10100111 10101000 10101001 10101010 10101011 10101100 10101101 10101110 10101111 10110000 10110001 10110010 10110011 10110100 10110101 10110110 10110111 10111000 10111001 10111010 10111011 10111100 10111101 10111110 10111111 11000000 11000001 Rev. C | Page 89 of 92 Volume Attenuation (dB) −54.375 −54.75 −55.125 −55.5 −55.875 −56.25 −56.625 −57 −57.375 −57.75 −58.125 −58.5 −58.875 −59.25 −59.625 −60 −60.375 −60.75 −61.125 −61.5 −61.875 −62.25 −62.625 −63 −63.375 −63.75 −64.125 −64.5 −64.875 −65.25 −65.625 −66 −66.375 −66.75 −67.125 −67.5 −67.875 −68.25 −68.625 −69 −69.375 −69.75 −70.125 −70.5 −70.875 −71.25 −71.625 −72 −72.375 ADAU1761 Binary Value 11000010 11000011 11000100 11000101 11000110 11000111 11001000 11001001 11001010 11001011 11001100 11001101 11001110 11001111 11010000 11010001 11010010 11010011 11010100 11010101 11010110 11010111 11011000 11011001 11011010 11011011 11011100 11011101 11011110 11011111 11100000 11100001 11100010 11100011 11100100 11100101 11100110 11100111 11101000 11101001 11101010 11101011 11101100 11101101 11101110 11101111 11110000 11110001 11110010 Volume Attenuation (dB) −72.75 −73.125 −73.5 −73.875 −74.25 −74.625 −75 −75.375 −75.75 −76.125 −76.5 −76.875 −77.25 −77.625 −78 −78.375 −78.75 −79.125 −79.5 −79.875 −80.25 −80.625 −81 −81.375 −81.75 −82.125 −82.5 −82.875 −83.25 −83.625 −84 −84.375 −84.75 −85.125 −85.5 −85.875 −86.25 −86.625 −87 −87.375 −87.75 −88.125 −88.5 −88.875 −89.25 −89.625 −90 −90.375 −90.75 Binary Value 11110011 11110100 11110101 11110110 11110111 11111000 11111001 11111010 11111011 11111100 11111101 11111110 11111111 Volume Attenuation (dB) −91.125 −91.5 −91.875 −92.25 −92.625 −93 −93.375 −93.75 −94.125 −94.5 −94.875 −95.25 −95.625 Table 95. R29 through R33 Volume Settings Binary Value 000000 000001 000010 000011 000100 000101 000110 000111 001000 001001 001010 001011 001100 001101 001110 001111 010000 010001 010010 010011 010100 010101 010110 010111 011000 011001 011010 011011 011100 011101 011110 011111 100000 Rev. C | Page 90 of 92 Volume Setting (dB) −57 −56 −55 −54 −53 −52 −51 −50 −49 −48 −47 −46 −45 −44 −43 −42 −41 −40 −39 −38 −37 −36 −35 −34 −33 −32 −31 −30 −29 −28 −27 −26 −25 ADAU1761 Binary Value 100001 100010 100011 100100 100101 100110 100111 101000 101001 101010 101011 101100 101101 101110 101111 110000 110001 110010 110011 110100 110101 110110 110111 111000 111001 111010 111011 111100 111101 111110 111111 Volume Setting (dB) −24 −23 −22 −21 −20 −19 −18 −17 −16 −15 −14 −13 −12 −11 −10 −9 −8 −7 −6 −5 −4 −3 −2 −1 0 1 2 3 4 5 6 Rev. C | Page 91 of 92 ADAU1761 OUTLINE DIMENSIONS 0.60 MAX 5.00 BSC SQ 0.60 MAX PIN 1 INDICATOR 0.50 BSC 4.75 BSC SQ 0.50 0.40 0.30 17 16 0.30 0.23 0.18 3.65 3.50 SQ 3.35 9 8 0.25 MIN 3.50 REF 0.05 MAX 0.02 NOM SEATING PLANE 1 EXPOSED PAD (BOTTOM VIEW) 0.80 MAX 0.65 TYP 12° MAX 32 0.20 REF COPLANARITY 0.08 FOR PROPER CONNECTION OF THE EXPOSED PAD, REFER TO THE PIN CONFIGURATION AND FUNCTION DESCRIPTIONS SECTION OF THIS DATA SHEET. COMPLIANT TO JEDEC STANDARDS MO-220-VHHD-2 100608-A TOP VIEW 1.00 0.85 0.80 PIN 1 INDICATOR 25 24 Figure 71. 32-Lead Lead Frame Chip Scale Package [LFCSP_VQ] 5 mm × 5 mm Body, Very Thin Quad (CP-32-4) Dimensions shown in millimeters ORDERING GUIDE Model 1 ADAU1761BCPZ ADAU1761BCPZ-R7 ADAU1761BCPZ-RL EVAL-ADAU1761Z 1 Temperature Range −40°C to +85°C −40°C to +85°C −40°C to +85°C Package Description 32-Lead Lead Frame Chip Scale Package [LFCSP_VQ] 32-Lead Lead Frame Chip Scale Package [LFCSP_VQ], 7” Tape and Reel 32-Lead Lead Frame Chip Scale Package [LFCSP_VQ], 13” Tape and Reel Evaluation Board Z = RoHS Compliant Part. ©2009–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07680-0-9/10(C) Rev. C | Page 92 of 92 Package Option CP-32-4 CP-32-4 CP-32-4