LM4930 Audio Subsystem with Stereo Headphone & Mono Speaker Amplifiers General Description Key Specifications The LM4930 is an integrated audio subsystem that supports voice and digital audio functions. The LM4930 includes a high quality I2S input stereo DAC, a voice band codec, a stereo headphone amplifier and a high-power mono speaker amplifier. It is primarily designed for demanding applications in mobile phones and other portable devices. The LM4930 features an I2S serial interface for full range audio, a 16-bit PCM bi-directional serial interface for the voice band codec and an two-wire interface for control. The full range music path features an SNR of 86dB with a 16-bit 48kHz input. The stereo DAC can also be used while the voice codec is in use. The headphone amplifier delivers 25mWRMS to a 32Ω single-ended stereo load with less than 0.5% distortion (THD+N) when AVDD = 3V. The mono speaker amplifier delivers up to 300mW into an 8Ω load with less than 2% distortion when AVDD = 3V. The LM4930 employs advanced techniques to reduce power consumption, to reduce controller overhead and to eliminate click and pop. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. It is, therefore, ideally suited for mobile phone and other low voltage applications where minimal power consumption is a primary requirement. j PH/P OUT at AVDD = 3.0V, 32Ω 0.5% THD+N j PLS OUT 25mW (typ) at AVDD = 3.0V, 8Ω 2% THD+N 300mW (typ) j Supply voltage range DVDD (Note 8) 2.6V to 4.5V AVDD (Note 8) 2.6V to 5.5V j Total shutdown current j PSRR at 217Hz, AVDD = 3V 2µA (typ) 50dB (typ) Features 16-bit resolution 48kHz stereo DAC 16-bit resolution 8kHz voice codec I2S digital audio data serial interface Two-wire serial control interface PCM voice audio data serial interface 25mW/channel stereo headphone amplifier 300mW mono 8Ω amplifier (at AVDD = 3.0V) 32-step volume control for audio output amplifiers No snubber networks or bootstrap capacitors are required by the headphone or hands-free amplifiers n Digital sidetone generation with adjustable attenuation n Gain controllable headphone amp, mono BTL amp, mic preamp n Available in the 36 bump micro SMD package n n n n n n n n n Applications n Mobile Phones n Mobile/low power audio appliances n PDAs Boomer ® is a registered trademark of National Semiconductor Corporation. © 2003 National Semiconductor Corporation DS200720 www.national.com LM4930 Audio Subsystem with Stereo Headphone & Mono Speaker Amplifiers July 2003 LM4930 Typical Application 20072003 FIGURE 1. Typical I2S + Voice codec application circuit for mobile phones www.national.com 2 LM4930 Connection Diagrams 36-Bump micro SMD micro SMD Marking 20072056 Top View X - Date Code T - Die Traceability G - Boomer Family B6 - LM4930ITL 20072002 Top View Order Number LM4930ITL See NS Package Number MKT-TLA36KRA Pin Descriptions A1 MIC_P Microphone positive differential input A2 MIC_N Microphone negative differential input A3 AVDD_MIC Analog Vdd for microphone preamp A4 DAC_REF D/A converter reference voltage A5 SDA Two-wire control interface serial data pin A6 SCL Two-wire control interface serial clock pin B1 AGND_MIC Analog ground for microphone preamp B2 MIC_BIAS Microphone bias supply output (2V) B3 MIC_REF Internal fixed-reference bypass capacitor decoupling pin B4 ADDR Control bus address select pin B5 PCM_SDI PCM serial data in B6 PCM_CLK PCM Serial clock pin C1 AVDD_HP Analog Vdd for headphone amplifier C2 NC No Connect C3 BYPASS Half-supply bypass capacitor decoupling pin C4 PCM_SYNC PCM Frame sync pin C5 I2S_DATA I2S serial data input C6 DGND_D Digital ground D1 HP_L Headphone amplifier connection (Left) D2 HP_R Headphone amplifier connection (Right) D3 HPSENSE_IN Connection for sense pin of headphone jack D4 PCM_SDO PCM serial data out D5 I2S_CLK I2S serial bit clock D6 DVDD_D Digital Vdd E1 AGND_HP Analog ground for headphone amplifier E2 LS- Loudspeaker amplifier BTL negative out (-) E3 HPSENSE_OUT Logic output pin to indicate headphone connection status. Outputs logic high when HPSENSE_IN is high and outputs logic low when HPSENSE_IN is low. See Figure 5 for suggested application circuit E4 IRQ LM4930 mode status indicator pin E5 I2S_WS I2S word select E6 XTAL_OUT Negative feedback source for external crystal MCLK F1 AGND_LS Analog ground for loudspeaker amplifier 3 www.national.com LM4930 Pin Descriptions (Continued) F2 LS+ Loudspeaker amplifier BTL positive out (+) F3 AVDD_LS Analog VDD for loudspeaker amplifier F4 DGND_X Digital ground F5 DVDD_X Digital VDD F6 MCLK/XTAL_IN 12.288MHz or 24.576MHz Master Clock from crystal (via XTAL OUT) or external source SYSTEM CONTROL REGISTERS The LM4930 is controlled with a two-wire serial interface. This interface is used to configure the operating mode, digital interfaces, and delta-sigma modulators. The LM4930 is controlled by writing information into a series of write-only registers, each with its own unique 7 bit address. The following registers are programmable: Basic Config Register This register is used to configure the I2S and PCM interfaces as well as the 48kHz DAC module. The 7 bit address for the BASICCONFIG register is XX10000. (X = 0 if ADDR is set to logic 0) (X = 1 if ADDR is set to logic 1) BASIC CONFIGURATION (XX1000). (Set = logic 1, Clear = logic 0) BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RESET 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Address Register Description 3:0 MODE The LM4930 can be placed in one of several modes that dictate the basic operation. When a new mode is selected the LM4930 will change operation silently and will reconfigure the power management profile automatically. The modes are described as follows: (Note 14) Mode Mono Speaker Amplifier Source Headphone Left Source Headphone Right Comment Source 0000 None None None Powerdown mode 0001 None None None Standby Mode 0010 Voice None None Mono speaker mode 0011 None Voice Voice Headphone call mode 0100 Voice Voice Voice Conference call mode 0101 Audio (L+R) None None L+R mixed to mono speaker 0110 None Audio (Left) Audio (Right) Headphone stereo audio 0111 Audio (L+R) Audio (Left) Audio (Right) L+R mixed to mono speaker + stereo headphone audio 1000 Audio (Left) Voice Voice Mixed Mode 1001 Voice + Audio (Left) Voice Voice Mixed mode 1010 Voice Audio (Left) Audio (Left) Mixed Mode 4 SOFT_RESET Resets the LM4930, excluding the control registers 5 PCM_LONG If set the PCM interface uses a long frame sync. (Note 12) 6 PCM_COMPANDED If set the 8 MSBs are presumed to be companded data and the 8 LSBs are ignored. (Note 12) 7 PCM_LAW If set, the companded G711 data is set to be A-law, else m-law is assumed (Note 12) 8:9 PCM_SYNC_MODE Sets 1 (00h), 2 (01h) or 4(10h) 16 bit frames per sync. The PCM_SDO pin is tri-stated during the latter frames. (Note 12) www.national.com 4 Basic Config Register LM4930 SYSTEM CONTROL REGISTERS (Continued) (Continued) 10 PCM_ALWAYS_ON This bit should be set if another codec is using the PCM bus. When set, the LM4930 will drive the clock and sync signals in all modes except Powerdown (Note 12) 11 I2S_M/S I2S master or slave select. If set then I2S = master. Cleared = slave 12 I2S_RES I2S resolution select. If set then 32 bits per frame. If cleared then 16 bits per frame 13 RSVD RESERVED (Note 13) 14 RSVD RESERVED (Note 13) 15 RSVD RESERVED (Note 13) Voice/Test Config Registers This register configures the voiceband codec, sidetone attenuation, and selected control functions. The 7 bit address for the VOICE TESTCONFIG register is XX10001. (X = 0 if ADDR is set to logic 0) (X = 1 if ADDR is set to logic 1) VOICETESTCONFIG (XX10001). (Set = logic 1, Clear = logic 0) BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RESET 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Address Register Description 0 CLASS If set, configures the chip for use with an external class D or linear amplifier and turns the BTL speaker output into a buffer. (Note 12) 4:1 SIDESTONE_ATTEN Programs the attenuation of the digital sidetone. Attenuation is set as follows: 4:1 Sidetone Attenuation 4:1 Sidetone Attenuation 0000 Mute 1000 -9dB 0001 -30dB 1001 -6dB 0010 -27dB 1010 -3dB 0011 -24dB 1011 0dB 0100 -21dB 1100 Mute 0101 -18dB 1101 Mute 0110 -15dB 1110 Mute 0111 -12dB 1111 Mute 5 AUTOSIDE This feature is included for use with the mono speaker in hands-free applications where sidetones may not be desirable. If set, the sidetone is always muted in voice over mono speaker modes (0010, 0100, 1001, and 1010), otherwise the sidetone is present at whatever level is set in the gain control register 6 CLOCK_DIV If set, allows for the use of a 24.576MHz crystal. Default setting is for 12.288MHz crystal. (Note 12) 7 ZXD_DISABLE Disables the zero crossing detect in the stereo DAC to guarantee immediate mode changes rather than waiting for a zero cross. (Note 11) 8:9 RSVD RESERVED (Note 13) 10:11 CAP_SIZE Set to accomodate different bypass capacitor values to give correct turn-off delay and click/pop performance. Value is set as follows: (Note 12) 10:11 Delay Bypass Capacitor Size 00 25ms 0.1µF 01 50ms 0.39µF 10 85ms 1µF 11 RESERVED RESERVED 12 ZXDS_SLOW If set, this forces the stereo DAC outputs to wait for a zero crossing before powering down 13 MUTE_LS If set, mutes the loudspeaker amplifier in any mode where it is not already muted 14 MUTE_HP If set, mutes the headphone amplifier in any mode where it is not already muted 15 MUTE_MIC If set, mutes the microphone preamp 5 www.national.com LM4930 SYSTEM CONTROL REGISTERS (Continued) Gain Config Registers This register is used to control the gain of the headphone amplifier, the loudspeaker amplifier, and the microphone preamplifier. The 7 bit address for the GAINCONFIG register is XX10010. (X = 0 if ADDR is set to logic 0) (X = 1 if ADDR is set to logic 1) GAINCONFIG (XX10010). (Set = logic 1, Clear = logic 0) BIT 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 RESET 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Address Register Description 4:0 LOUDSPKR_GAIN Programs the gain of the loudspeaker amplifier. Gain is set as follows: 9:5 13:10 www.national.com HP_GAIN MIC_GAIN 4:0 Loudspeaker Gain 4:0 Loudspeaker Gain 00000 -34.5dB 10000 -10.5dB 00001 -33dB 10001 -9dB 00010 -31.5dB 10010 -7.5dB 00011 -30dB 10011 -6dB 00100 -28.5dB 10100 -4.5dB 00101 -27dB 10101 -3dB 00110 -25.5dB 10110 -1.5dB 00111 -24dB 10111 0dB 01000 -22.5dB 11000 1.5dB 01001 -21dB 11001 3dB 01010 -19.5dB 11010 4.5dB 01011 -18dB 11011 6dB 01100 -16.5dB 11100 7.5dB 01101 -15dB 11101 9dB 01110 -13.5dB 11110 10.5dB 01111 -12dB 11111 12dB Programs the gain of the headphone amplifier. Gain is set as follows: 9:5 Headphone Gain 9:5 Headphone Gain 00000 -46dB 10000 -22.5dB 00001 -45dB 10001 -21dB 00010 -43.5dB 10010 -19.5dB 00011 -42db 10011 -18dB 00100 -40.5dB 10100 -16.5dB 00101 -39dB 10101 -15dB 00110 -37.5dB 10110 -13.5dB 00111 -36dB 10111 -12dB 01000 -34.5dB 11000 -10.5dB 01001 -33dB 11001 -9dB 01010 -31.5dB 11010 -7.5dB 01011 -30dB 11011 -6dB 01100 -28.5dB 11100 -4.5dB 01101 -27dB 11101 -3dB 01110 -25.5dB 11110 -1.5dB 01111 -24dB 11111 0dB Programs the gain of the microphone amplifier. Gain is set as follows: 6 Gain Config Registers 15:14 RSVD LM4930 SYSTEM CONTROL REGISTERS (Continued) (Continued) 13:10 Mic Preamp Gain 0000 17dB 0001 19dB 0010 21dB 0011 23dB 0100 25dB 0101 27dB 0110 29dB 0111 31dB 1000 33dB 1001 35dB 1010 37dB 1011 39dB 1100 41dB 1101 43dB 1110 45dB 1111 47dB RESERVED (Note 13) 20072009 Two-wire control Interface Timing Diagram FIGURE 2. 20072008 PCM Receive Timing Diagram FIGURE 3. 7 www.national.com LM4930 20072007 I2S Transmit Timing Diagram FIGURE 4. www.national.com 8 Junction temperature (Notes 1, 150˚C Thermal Resistance 2) θJA - TLA36KRA If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Analog Supply Voltage 6.0V Digital Storage Supply Voltage 6.0V Storage temperature Power Dissipation (Note 3) Operating Ratings (Note 3) Temperature Range TMIN ≤ TA ≤ TMAX -65˚C to +150˚C Machine Model (Note 5) −30˚C ≤ TA ≤ +85˚C Supply Voltage Internally Limited ESD Susceptibility Human Body Model (Note 4) 105˚C/W 2000V DVDD (Note 8) 2.6V - 4.5V AVDD (Note 8) 2.6V - 5.5V 200V Electrical Characteristics DVDD = 3.3V, AVDD = 5V, RLHP = 32Ω, RLHF = 8Ω (Notes 1, 2, 8) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) Limits (Notes 7, 15) Units (Limits) fMCLK = 12.288MHz DIDD Digital Power Supply Current Output Mode = "0010" Output Mode = "0011" Output Mode = "0100" 2 Output Mode = "0101" Output Mode = "0110" Output Mode = "0111" 4.4 Output Mode = "1000" Output Mode = "1001" Output Mode = "1010" 4.9 8 mA (max) fMCLK = 12.288MHz; No Load AIDD Analog Power Supply Quiescent Current Output Mode = "0010" 7.0 Output Mode = "0011" 6.3 Output Mode = "0100" 8.0 Output Mode = "0101" 8.2 Output Mode = "0110" 7.4 Output Mode = "0111" 8.7 Output Mode = "1000" Output Mode = "1001" Output Mode = "1010" 9.5 14 mA (max) 1 7 µA (max) 1 2 µA (max) DISD Digital Powerdown Current fMCLK = 12.288MHz Output Mode = "0000" Powerdown Mode AISD Analog Powerdown Current fMCLK = 12.288MHz Output Mode = "0000" Powerdown Mode DIST Digital Standby Current fMCLK = 12.288MHz Output Mode = "0001"Standby Mode 1.4 2 mA (max) AIST Analog Standby Current fMCLK = 12.288MHz Output Mode = "0001"Standby Mode 230 1000 µA (max) VFS_LS Full-Scale Output Voltage (Mono speaker amplifier) CLASS = 0; 0dB gain setting; 8Ω BTL load (Note 10) 2.5 VP-P VFS_HP Full-Scale Output Voltage (Headphone amplifier) 0dB gain setting; 32Ω Stereo Load (Note 10) 2.5 VP-P 9 www.national.com LM4930 Absolute Maximum Ratings LM4930 Electrical Characteristics DVDD = 3.3V, AVDD = 5V, RLHP = 32Ω, RLHF = 8Ω (Notes 1, 2, 8) (Continued) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) VMIC_BIAS Mic Bias Voltage Limits (Notes 7, 15) Units (Limits) 2.0 V 0.07 % THD+N Headphone Amplifier Total Harmonic Motion Distortion + Noise fIN = 1 kHz, POUT = 7.5mW; 32Ω Stereo Load POHP Headphone Amplifier Output Power THD+N = 0.5%, fOUT = 1kHz 27 POLS Mono Speaker Amplifier Output Power THD+N = 3%, fOUT = 1kHz 1 PSRR Power Supply Rejection Ratio CBYPASS = 1.0µF CDAC_REF = 1.0µF VRIPPLE = 200mVP-P @ 217Hz, MIC_P, MIC_N terminated with 10Ω to ground 55 SNR (Voice) Signal-to-Noise Ratio (Voice Audio Path) Signal = Vo at f = 1kHz @1% THD+N, 32Ω Stereo Load; Noise = digital zero, A-weighted, 0dB gain setting 72 dB SNR (Music) Signal-to-Noise Ratio (Music Audio Path) Signal = Vo at f = 1kHz @1% THD+N, 32Ω Stereo Load; Noise = digital zero, A-weighted; 0dB gain setting 86 dB DR (Voice) Dynamic Range (Voice Audio Path) Signal = Vo at f = 1kHz @1% THD+N, 32Ω Stereo Load; Noise for -60dBFS digital input; A-weighted; 0dB gain setting 72 dB DR (Music) Dynamic Range (Music Audio Path) Signal = Vo at f=1kHz @1% THD+N, 32Ω Stereo Load; Noise for -60dBFS digital input; A-weighted, 0dB gain setting 86 dB SNRADC Signal-to-Noise Ratio (Voice ADC Path) Reference signal = 0dBFS MIC_P, MIC_N terminated with 10Ω to ground; A-weighted; 47dB MIC preamp gain setting 75 dB DRADC Dynamic Range (Voice ADC Path) Reference signal = 0dBFS Noise for -60dBFS digital input; A-weighted; 47dB MIC preamp gain setting 75 dB XTALK Stereo Channel-to-Channel Crosstalk fS = 48kHz, fIN = 1kHz sinewave at -3dBFS 75 dB VMIC-IN Maximum Differential MIC Input Voltage 17dB MIC Preamp gain setting 570 mVP-P RVDAC Voice DAC Ripple 300Hz - 3.3kHz through head-phone output. +/-0.15 +/-0.2 dB (max) RVADC Voice ADC Ripple 300Hz - 3.3kHz through head-phone output. +/-0.25 +/-0.3 dB (max) PBVDAC Voice DAC Passband -3dB Point 3.46 SBAVDAC Voice DAC Stopband Attenuation Above 4kHz UPBVADC Voice ADC Upper Passband Cutoff Frequency. Upper -3dB Point www.national.com 10 20 mW (min) W 45 dB (min) kHz 72 dB 3.47 kHz (Notes 1, 2, 8) (Continued) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) LPBVADC Voice ADC Lower Passband Cutoff Frequency. Lower -3dB Point SBAVADC Voice ADC Stopband Attenuation SBANOTCH Voice ADC Notch Attenuation Limits (Notes 7, 15) Units (Limits) 0.230 kHz Above 4kHz 65 dB Centered on 55Hz, figure gives worst case attenuation for 50Hz & 60Hz. 58 dB RDAC Audio DAC Ripple 20Hz - 20kHz through head-phone output. PBDAC Audio DAC Passband Width -3dB point SBADAC Audio DAC Stopband Attenuation DRDAC Audio DAC Dynamic Range Digital Filter Section SNRDAC Audio DAC SNR Digital Filter Section ∆ACH-CH +/-0.1 +/-0.2 dB (max) 22.7 kHz Above 24kHz 76 dB Signal = VO at f = 1kHz @ 1% THD+N; f = 1kHz; Noise for -60dBFS digital input; 0dB gain; A-weighted 97 dB Signal = VO at f = 1kHz @ 1% THD+N; f = 1kHz; Noise for -60dBFS digital input; 0dB gain; A-weighted 97 dB Stereo Channel-to-Channel Gain Mismatch 0.3 dB VIL Digital Input: Logic Low Voltage Level 0.4 V VIH Digital Input: Logic High Voltage Level 1.4 V Volume Control Range (Headphone amplifiers) Maximum Attenuation Minimum Attenuation -46.5 0 dB dB Volume Control Range (Mono speaker amplifier) Minimum Gain Maximum Gain -34.5 12 dB dB 1.5 dB 17 47 dB dB 2 dB -30 0 dB dB Volume Control Step Size (Output amplifiers) Volume Control Range (Microphone Preamp) Minimum Gain Maximum Gain Volume Control Step Size (Microphone Preamp) Side Tone Attenuation Range Maximum Attenuation Minimum Attenuation Side Tone Attenuation Step Size fMCLK MCLK frequency CLOCK_DIV = 0 CLOCK_DIV = 1 3 dB 12.288 24.576 MHz MHz MCLK Duty Cycle 50 fCONV Sampling Clock Frequency (Note 9) 48 kHz fCLKSCL SCL_CLK Frequency 400 kHz tRISESCL SCL_CLK, SCL_DATA Rise Time 300 ns tFALLSCL SCL_CLK, SDA_DATA Fall Time 300 ns tSDAH SDA_DATA Hold Time 500 ns tSDAS SDA_DATA Setup Time 500 ns 11 40 60 % (min) % (max) www.national.com LM4930 Electrical Characteristics DVDD = 3.3V, AVDD = 5V, RLHP = 32Ω, RLHF = 8Ω LM4930 Electrical Characteristics DVDD = 3.3V, AVDD = 5V, RLHP = 32Ω, RLHF = 8Ω (Notes 1, 2, 8) (Continued) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) fCLKPCM PCM_CLK Frequency PCM_SYNC_MODE = 00 PCM_SYNC_MODE = 01 PCM_SYNC_MODE = 10 PCM_CLK Duty Cycle fCLKI2S I2S_CLK Frequency Limits (Notes 7, 15) 128 256 512 kHz 50 I2S_RES = 0 I2S_RES = 1 40 60 1.536 3.072 I2S_CLK Duty Cycle Units (Limits) % (min) % (max) MHz 50 40 60 % (min) % (max) Electrical Characteristics DVDD = 3V, AVDD = 3V, RLHP = 32Ω, RLHF = 8Ω (Notes 1, 2, 3) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) Limits (Notes 7, 15) Units (Limits) fMCLK = 12.288MHz DIDD Digital Power Supply Current Output Mode = "0010" Output Mode = "0011" Output Mode = "0100" 1.6 Output Mode = "0101" Output Mode = "0110" Output Mode = "0111" 3.8 Output Mode = "1000" Output Mode = "1001" Output Mode = "1010" 4.2 7 mA (max) fMCLK = 12.288MHz; No Load AIDD Analog Power Supply Quiescent Current Output Mode = "0010" 5.8 Output Mode = "0011" 5.1 Output Mode = "0100" 6.5 Output Mode = "0101" 6.4 Output Mode = "0110" 5.8 Output Mode = "0111" 7.0 Output Mode = "1000" Output Mode = "1001" Output Mode = "1010" 7.5 12 mA (max) 1 7 µA (max) DISD Digital Powerdown Current fMCLK = 12.288MHz Output Mode = "0000" Powerdown Mode AISD Analog Powerdown Current fMCLK = 12.288MHz Output Mode = "0000" Powerdown Mode 0.6 1.5 µA (max) DIST Digital Standby Current fMCLK = 12.288MHz Output Mode = "0001" Standby Mode 1.1 1.7 mA (max) www.national.com 12 (Notes 1, 2, 3) (Continued) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) Limits (Notes 7, 15) 100 300 Units (Limits) AIST Analog Standby Current fMCLK = 12.288MHz Output Mode = "0001" Standby Mode VFS_LS Full-Scale Output Voltage (Mono speaker amplifier) CLASS = 0; 0dB gain setting; 8Ω BTL load (Note 10) 2.5 VP-P VFS_HP Full-Scale Output Voltage (Headphone amplifier) 0dB gain setting; 32Ω Stereo Load (Note 10) 2.5 VP-P 2 V 0.07 % VMIC_BIAS Mic Bias Voltage µA (max) THD+N Headphone Amplifier Total Harmonic Distortion + Noise fIN = 1kHz, POUT = 7.5mW POHP Headphone Amplifier Output Power THD+N = 0.5%, fOUT = 1kHz 25 15 mW (min) POLS Mono Speaker Amplifier Output Power THD+N = 2%, fOUT = 1kHz 300 270 mW (min) PSRR Power Supply Rejection Ratio CBYPASS = 1.0µF CDAC_REF = 1.0µF VRIPPLE = 200mVP-P @ 217Hz 50 42 dB (min) SNR (Voice) Signal-to-Noise Ratio (Voice Audio Path) Signal = Vo at f = 1kHz @1% THD+N, 32Ω Stereo Load; Noise = digital zero, A-weighted; 0dB gain setting 72 dB SNR (Music) Signal-to-Noise Ratio (Music Audio Path) Signal = Vo at f = 1kHz @1% THD+N, 32Ω Stereo Load; Noise = digital zero, A-weighted; 0dB gain setting 86 dB DR (Voice) Dynamic Range (Voice Audio Path) Signal = Vo at f = 1kHz @1% THD+N, 32Ω Stereo Load; Noise for -60dBFS digital input; A-weighted, 0dB gain setting 72 dB DR (Music) Dynamic Range (Music Audio Path) Signal = Vo at f=1kHz @1% THD+N, 32Ω Stereo Load; Noise for -60dBFS digital input; A-weighted, 0dB gain setting 86 dB SNRADC Signal-to-Noise Ratio (Voice ADC Path) Reference signal = 0dBFS MIC_P, MIC_N terminated with 10Ω to ground; A-weighted; 47dB MIC preamp gain setting 75 dB DRADC Dynamic Range (Voice ADC Path) Reference signal = 0dBFS Noise for -60dBFS digital input; A-weighted; 47dB MIC preamp gain setting 75 dB XTALK Stereo Channel-to-Channel Crosstalk fS = 48kHz, fIN = 1kHz sinewave at -3dBFS 73 dB VMIC-IN Maximum Differential MIC Input Voltage 17dB MIC Preamp gain setting 570 mVP-P RVDAC Voice DAC Ripple 300Hz - 3.3kHz through head-phone output. +/-0.15 +/-0.2 dB (max) RVADC Voice ADC Ripple 300Hz - 3.3kHz through head-phone output. +/-0.25 +/-0.3 dB (max) PBVDAC Voice DAC Passband -3dB Point 3.46 13 kHz www.national.com LM4930 Electrical Characteristics DVDD = 3V, AVDD = 3V, RLHP = 32Ω, RLHF = 8Ω LM4930 Electrical Characteristics DVDD = 3V, AVDD = 3V, RLHP = 32Ω, RLHF = 8Ω (Notes 1, 2, 3) (Continued) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) Limits (Notes 7, 15) Units (Limits) SBAVDAC Voice DAC Stopband Attenuation Above 4kHz 72 dB UPBVADC Voice ADC Upper Passband Cutoff Frequency. Upper -3dB Point 3.47 kHz LPBVADC Voice ADC Lower Passband Cutoff Frequency. Lower -3dB Point 0.230 kHz SBAVADC Voice ADC Stopband Attenuation Above 4kHz 65 dB SBANOTCH Voice ADC Notch Attenuation Centered on 55Hz, figure gives worst case attenuation for 50Hz & 60Hz. 58 dB RDAC Audio DAC Ripple 20Hz - 20kHz through head-phone output. PBDAC Audio DAC Passband Width -3dB point SBADAC Audio DAC Stopband Attenuation DRDAC +/-0.1 +/-0.2 dB (max) 22.7 kHz Above 24kHz 76 dB Audio DAC Dynamic Range Digital Filter Section Signal = VO at f = 1kHz @ 1% THD+N; f = 1kHz; Noise for -60dBFS digital input; 0dB gain; A-weighted 97 dB SNRDAC Audio DAC SNR Digital Filter Section Signal = VO at f = 1kHz @ 1% THD+N; f = 1kHz; Noise for -60dBFS digital input; 0dB gain; A-weighted 97 dB ∆ACH-CH Stereo Channel-to-Channel Gain Mismatch 0.3 dB VIL Digital Input: Logic Low Voltage Level 0.4 V VIH Digital Input: Logic High Voltage Level 1.4 V Volume Control Range (Headphone amplifiers) Maximum Attenuation Minimum Attenuation -46.5 0 dB dB Volume Control Range (Mono speaker amplifier) Minimum Gain Maximum Gain -34.5 12 dB dB 1.5 dB 17 47 dB 2 dB -30 0 dB dB Volume Control Step Size (Output amplifiers) Volume Control Range (Microphone Preamp) Minimum Gain Maximum Gain Volume Control Step Size (Microphone Preamp) Side Tone Attenuation Range Maximum Attenuation Minimum Attenuation Side Tone Attenuation Step Size fMCLK MCLK frequency CLOCK_DIV = 0 CLOCK_DIV = 1 MCLK Duty Cycle fCONV Sampling Clock Frequency fCLKSCL tRISESCL 3 dB 12.288 24.576 MHz MHz 50 % (min) % (max) 48 kHz SCL_CLK Frequency 400 kHz SCL_CLK, SCL_DATA Rise Time 300 ns tFALLSCL SCL_CLK, SDA_DATA Fall Time 300 ns tSDAH SDA_DATA Hold Time 500 ns www.national.com (Note 9) 40 60 14 (Notes 1, 2, 3) (Continued) The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA= 25˚C. Symbol Parameter Conditions LM4930 Typical (Note 6) tSDAS SDA_DATA Setup Time fCLKPCM PCM_CLK Frequency PCM_SYNC_MODE = 00 PCM_SYNC_MODE = 01 PCM_SYNC_MODE = 10 PCM_CLK Duty Cycle fCLKI2S I2S_CLK Frequency 500 ns 128 256 512 kHz kHz kHz 50 I2S_RES = 0 I2S_RES = 1 Limits (Notes 7, 15) 40 60 1.536 3.072 I2S_CLK Duty Cycle Units (Limits) 50 % (min) % (max) MHz MHz 40 60 % (min) % (max) Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device performance. Note 2: All voltages are measured with respect to the relevant GND pin unless otherwise specified. Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX ,θJA, and the ambient temperature, TA. The maximum allowable power dissipation is PDMAX = (TJMAX – TA) / θJA or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4930, see power derating currents for more information. Note 4: Human body model: 100pF discharged through a 1.5kΩ resistor. Note 5: Machine model: 220pF - 240pF discharged through all pins. Note 6: Typicals are measured at 25˚C and represent the parametric norm. Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 8: Best operation is achieved by maintaining 3.0V ≤ AVDD ≤ 5.0 and 3.0V ≤ DVDD ≤ 3.6V. AVDD must be equal to or greater than DVDD. for proper operation. Note 9: The sampling clock frequency is equal to the master clock frequency divided by 256. (fconv = fMCLK/256) Note 10: This value represents the 0dB output level of the given amplifier for the given analog supply voltage. Gain values given in the GAINCONFIG register are relative to these full-scale values for each output amplifier. Note 11: To ensure a successful transistion into Powerdown Mode, ZXD_DISABLE must be set whenever there is no audio input signal present. Note 12: It is recommended to alter this bit only while the part is in Powerdown Mode. Note 13: Reserved bits should be set to zero when programming the associated register. Note 14: With the exception of Standby Mode, rapid switching between modes should be avoided. Rapid switching between modes will not ensure that the desired mode will be activated. Note 15: Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. Note 16: 0dBm0 = -3dBFS for the PCM voice codec and 0dBm0 = -1dBFS for the I2S DAC, unless otherwise specified. 15 www.national.com LM4930 Electrical Characteristics DVDD = 3V, AVDD = 3V, RLHP = 32Ω, RLHF = 8Ω LM4930 Typical Performance Characteristics (Note 16) MIC PreAmp + ADC Frequency Response (MIC Gain = 17dB) MIC PreAmp + ADC Frequency Response Zoom (MIC Gain = 17dB) 20072015 20072016 MIC PreAmp + ADC Frequency Response (MIC Gain = 47dB) MIC PreAmp + ADC Frequency Response Zoom (MIC Gain = 47dB) 20072017 20072018 MIC PreAmp + ADC Frequency Response High Cutoff (MIC Gain = 17dB) MIC PreAmp + ADC Frequency Response High Cutoff (MIC Gain = 47dB) 20072019 www.national.com 20072020 16 (Note 16) MIC PreAmp + ADC Frequency Response Low Cutoff (MIC Gain = 17dB) (Continued) MIC PreAmp + ADC Frequency Response Low Cutoff (MIC Gain = 47dB) 20072021 20072022 ADC THD+N vs MIC Input Voltage (MIC Gain = 17dB) ADC THD+N vs MIC Input Voltage (MIC Gain = 47dB) 20072023 20072024 MIC PreAmp + ADC PSRR vs Frequency Top Trace = 47dB MIC Gain, Bottom Trace = 17dB MIC Gain Headphone Sense In Hysteresis Loop (AVDD = 3V) 20072027 20072026 17 www.national.com LM4930 Typical Performance Characteristics LM4930 Typical Performance Characteristics (Note 16) I2S DAC Frequency Response ( Handsfree Output) Headphone Sense In Hysteresis Loop (AVDD = 5V) 20072028 20072029 I2S DAC Frequency Response Zoom (Handsfree Output) I2S DAC Frequency Response Zoom (Headphone Output) 20072030 20072031 I2S DAC Frequency Response Zoom (Headphone Output) THD+N vs I2S Input Voltage (Handsfree Output, 0dB Handsfree Gain) 20072032 www.national.com (Continued) 20072038 18 (Note 16) THD+N vs I2S Input Voltage (Headphone Output, 0dB Headphone Gain) (Continued) I2S DAC Crosstalk (Top Trace = Left to Right, Bottom Trace = Right to Left) 20072039 20072040 MIC Bias Dropout Voltage vs MIC Bias Current PCM DAC Frequency Response (Handsfree Output) 20072041 20072055 PCM DAC Frequency Response Zoom (Handsfree Output) PCM DAC Frequency Response (Headphone Output) 20072050 20072049 19 www.national.com LM4930 Typical Performance Characteristics LM4930 Typical Performance Characteristics (Note 16) PCM DAC Frequency Response Zoom (Headphone Output) THD+N vs PCM Input Voltage (Handsfree Output, 0dB Handsfree Gain) 20072051 20072052 THD+N vs PCM Input Voltage (Headphone Output, 0dB Headphone Gain) Crosstalk (AVDD = 5V and AVDD = 3V, Headphone Output) 20072053 200720F9 PSRR vs Frequency (AVDD = 3V, RL = 32Ω, Headphone Output) PSRR vs Frequency (AVDD = 3V, RL = 16Ω, Headphone Output) 200720G0 www.national.com (Continued) 200720G1 20 (Note 16) PSRR vs Frequency (AVDD = 3V, RL = 8Ω, Handsfree Output) PSRR vs Frequency (AVDD = 5V, RL = 16Ω, Headphone Output) 200720G2 200720G3 PSRR vs Frequency (AVDD = 5V, RL = 8Ω, Handsfree Output) PSRR vs Frequency (AVDD = 5V, RL = 32Ω, Headphone Output) 200720G4 (AVDD (Continued) 200720G5 THD+N vs Frequency (AVDD = 5V and AVDD = 3V, RL = 16Ω, PO = 15mW, Headphone Output) THD+N vs Frequency = 3V, RL = 8Ω, PO = 150mW, Handsfree Output) 200720G6 200720G7 21 www.national.com LM4930 Typical Performance Characteristics LM4930 Typical Performance Characteristics (Note 16) THD+N vs Frequency (AVDD = 5V and AVDD = 3V, RL = 32Ω, PO = 7.5mW, Headphone Output) THD+N vs Frequency (AVDD = 5V, RL = 8Ω, PO = 250mW, Handsfree Output) 200720G8 200720G9 THD+N vs Output Power (AVDD = 3V, RL = 8Ω, f = 1kHz, Handsfree Output) THD+N vs Output Power AVDD = 3V, RL = 16Ω, f = 1kHz, Headphone Output) 200720H0 (AVDD 200720H1 THD+N vs Output Power (AVDD = 5V and AVDD = 3V, RL = 32Ω, f = 1kHz, Headphone Output) THD+N vs Output Power = 3V, RL = 8Ω, f = 1kHz, Handsfree Output) 200720H2 www.national.com (Continued) 200720H3 22 (Note 16) THD+N vs Output Power (AVDD = 5V and AVDD = 3V, RL = 16Ω, f = 1kHz, Headphone Output) LM4930 Typical Performance Characteristics (Continued) THD+N vs Output Power (AVDD = 5V, RL = 8Ω, f = 1kHz, Handsfree Output) 200720H4 200720H5 THD+N vs Output Power (AVDD = 5V, RL = 8Ω, f = 1kHz, Handsfree Output) 200720H6 23 www.national.com LM4930 Application Information REFERENCE DESIGN BOARD AND LAYOUT LM4930ITL BOARD LAYOUT 20072014 LM4930ITL Demo Board Schematic FIGURE 5. www.national.com 24 LM4930 Application Information (Continued) 20072006 LM4930ITL Demo Board Composite View FIGURE 6. 20072005 LM4930ITL Demo Board Silkscreen FIGURE 7. 25 www.national.com LM4930 Application Information (Continued) 20072004 LM4930ITL Demo Board Top Layer FIGURE 8. 20072013 LM4930ITL Demo Board Bottom Layer FIGURE 9. www.national.com 26 LM4930 Application Information (Continued) 20072012 LM4930ITL Demo Board Inner Layer 1 FIGURE 10. 20072011 LM4930ITL Demo Board Inner Layer 2 FIGURE 11. 27 www.national.com LM4930 Application Information (Continued) 20072010 Pin Markings for LM4930ITL demo board FIGURE 12. LM4930 DEMO BOARD BILL OF MATERIALS Comment Footprint Designators 1k 0805 R6, R7 2k 0805 R2, R3 20k 0805 R1 100k 0805 R5 1M 0805 R4 22pF 1210 C6, C7 0.01µF cer 1210 C16, C17 0.1µF cer 1210 C14, C15 1µF 1210 C1, C2, C3, C4, C5, C10, C11, C12, C13 220µF 7243 C8, C9 CRYSTAL 7243 Y1 PHONEJACK STEREO SW STEREOHEADPHONEJACK(3.5MM) J8 Two-wire control Interface (J1) www.national.com Pin Function 1 DVDD 2 SCL 3 DGND 4 NC 5 DGND 6 SDA 28 LM4930 Application Information (Continued) PCM Interface (P4, P3, P1, P2) Header Function P1 PCM_SDI P2 PCM_CLK P3 PCM_SYNC P4 PCM_SDO I2S Interface (J2) Pin Function 1 MCLK 2 I2S-CLK 3 I2S-DATA 4 I2S-WS 5 DGND 6 DGND 7 DGND 8 DGND 9 DGND 10 DGND MIC Jack Pin Function 1 AGND 2 MIC- 3 MIC+ Misc Jumpers and Headers DVDD/DGND (J10) Pin Function 1 DGND 2 AVDD Misc Jumpers and Headers AVDD/AGND (J9) Pin Function 1 AGND 2 AVDD Misc Jumpers and Headers MCLK/XTAL_IN (P5) Pin Function 1 DGND 2 MCLK/XTAL_IN ADR SELECT (S1) Jumper IN = LOW Control interface responds to addresses 001000b (BASICCONFIG), 0010001b (VOICETESTCONFIG)), and 0010010b (GAINCONFIG) Jumper OUT = HIGH Control interface responds to addresses 111000b (BASICCONFIG), 1110001b (VOICETESTCONFIG)), and 1110010b (GAINCONFIG) 29 www.national.com LM4930 Application Information (Continued) HP Sense Out (J6) Pin Function 1 AGND 2 HPSense_Out IRQ (J4) Pin Function 1 DGND 2 IRQ Onboard MCLK Select (S2) Jumper IN = Onboard MCLK Jumper OUT = External MCLK LM4930ITL DEMO BOARD OPERATION The LM4930ITL demo board is a complete evaluation platform, designed to give easy access to the control pins of the part and comprise all the necessary external passive components. Besides the separate analog (J9) and digital (J10) supply connectors, the board features seven other major input and control blocks: a two wire interface bus (J1) for the control lines, a PCM interface bus (P1-P4) for voiceband digital audio, an I2S interface bus (J2) for full-range digital audio, an analog mic jack input (J3) for connection to an external microphone, a BTL mono output (J7) for connection to an external speaker, a stereo headphone output (J8), and an external MCLK input (P5) for use in place of the crystal on the demoboard. Table 1. LM4930 Control Bus Addresses Address Bits ADR = 0 6 5 4 3 2 1 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 0 1 0 0 1 0 ADR = 1 Two-wire Interface Bus (J1) This is the main control bus for the LM4930. It is a two-wire interface with an SDA line (data) and SCL line (clock). Each transmission from the baseband controller to the LM4930 is given MSB first and must follow the timing intervals given in the Electrical Characteristics section of the datasheet to create the start and stop conditions for a proper transmission. The start condition is detected if SCL is high on the falling edge of SDA. The stop condition is detected if SCL is high on the rising edge of SDA. Repeated start signals are handled correctly. Data is then transmitted as shown in Figure 2. After the start condition has been achieved the chip address is sent, followed by a set write bit, wait for ack (SDA will be pulled low by LM4930), data bits 15-8, wait for ACK (SDA will be pulled low by LM4930), data bits 7-0, wait for ACK (SDA will be pulled low by LM4930)and finally the stop condition is given. This same sequence follows for any control bus transmission to the LM4930. The chip address is hardwire selected by the ADR Select pin which may be jumpered high or low with its application at S1 on the demo board. The chip address is then given as a combination of the identifying bits for the LM4930 plus the 2-bit address of the desired control register (00b = BasicConfig, 01b = VoicetestConfig, 10b = GainConfig). Acceptable addresses are shown here in Table 1. www.national.com Register Address 1 1 1 0 0 0 0 1 1 1 0 0 0 1 1 1 1 0 0 1 0 Data is sampled only if the address is in range and the R/W bit is clear. Data for each register is given in the System Control Registers section of the datasheet. National Semiconductor also features a special control board for quick evaluation of the LM4930 demo board with your PC. This is a serial control interface board, complete with header compatible with the interface header (J1) on the LM4930 board. This also features demonstration software to allow for complete control and evaluation of the various modes and functions of the LM4930 through the bus. Pullup resistors are required to achieve reliable operation. 750Ω pullup resistors on the SDA and SCL lines achieves best results when used with National’s parallel-to-serial interface board. Lower value pullup resistors will decrease the rise and fall times on the bus which will in turn decrease susceptibility to bus noise that may cause a false trigger. The cost comes at extra current use. Control bus reliability will thus depend largely on bus noise and may vary from design to design. Low noise is critical for reliable operation. PCM Bus Interface (P1, P2, P3, P4) PCM_SDO (P4), PCM_SYNC (P3), PCM_SDI (P1), and PCM_CLK (P2) form the PCM interface bus for simple communication with most baseband ICs with voiceband communications and follow the PCM-1900 communications standard. The PCM interface features frame lengths of 16, 32, or 64 bits, A-law and u-law companding, linear mode, short or long frame sync, an energy-saving power down mode, and master only operation. The PCM bus does not support a slave mode. It operates as a master only. Thus PCM_SYNC and PCM_CLK are solely generated by the LM4930. PCM_SYNC is the word sync line 30 faces with pins 1-5 of the I2S Interface Bus. Pins 6-10 are provided as digital ground references for the case of discrete connections. (Continued) for the bus. It operates at a fixed frequency of 8kHz and may be set in the BASICCONFIG register (bit 5 PCM_LONG) for short or long frame sync. A short frame sync is 1 PCM_CLK cycle (PCM_LONG=0), a long frame sync is 2 PCM_CLK cycles long (PCM_LONG=1). A long sync pulse is also delayed one clock cycle relative to a short sync pulse. This is illustrated in Figure 3. PCM_CLK is the bit clock for the bus. It’s frequency depends on the number of 16-bit frames per sync pulse and can be 128kHz, 256kHz, 512kHz. The other two lines, PCM_SDO and PCM_SDI, are for serial data out and serial data in, respectively. The type of data may also be set in the BASICCONFIG register by bits 6 and 7. Bit 6 controls whether the data is linear or companded. If set to 1, the 8 MSBs are presumed to be companded data and the 8 LSBs are ignored. If cleared to 0, the data is treated as 2’s complement PCM data. Bit 7 controls which PCM law is used if Bit 6 is set for companded (G711) data. If set to 1, the companded data is assumed to be A-law. If cleared to 0, the companded data is treated as µ-law. MCLK/XTAL_IN (P5) This is the input for an external Master Clock. The jumper at S2 must be removed (disconnecting the onboard crystal from the circuit) when using an external Master Clock. BTL Mono Out (J7) This is the mono speaker output, designed for use with an 8 ohm speaker. The outputs are driven in bridge-tied-load (BTL) mode, so both sides have signal. Outputs are normally biased at one half AVDD when the LM4930 is in active mode. Additionally, if the CLASS bit is set to 1 in the VOICETESTCONFIG register (bit 0) the BTL mono output is internally configured as a buffer amplifier designed for use with an external class D amp. Stereo Headphone Out (J8) This is the stereo headphone output. Each channel is singleended, with 220uF DC blocking capacitors mounted on the demo board. The jack features a typical stereo headphone pinout. A headphone sense pin is provided at J6. This pin provides a clean logic high or low output to indicate the presence of headphones in the headphone jack. A common application circuit for this is given in the Reference Board Schematic shown in Figure 5. In this application HPSENSE_IN is pulled low by the 1k ohm resistor when no headphone is present. This gives a corresponding logic low output on the HPSENSE_OUT pin. When a headphone is placed in the jack the 1k ohm pull-down is disconnected and a 100k ohm pull-up resistor creates a high voltage condition on HPSENSE_IN. This in turn creates a logic high on HPSENSE_OUT. This output may be used to reliably drive an external microcontroller with headphone status. Bits 8:9 of the BASICCONFIG register set the PCM_SYNC_MODE settings. This controls the number of 16 bit frames per sync pulse. The feature allows the LM4930 to function harmoniously with other devices or channels on the PCM bus by adjusting the number of 16 bit frames per sync pulse to 1 (00b), 2 (01b), or 4 (10b). The LM4930 will transmit PCM data in the first frame and then tri-state the PCM_SDO pin on later frames. In addition, the LM4930 provides control to allow the PCM_CLK and PCM_SYNC clocks to continue functioning even when the LM4930 is in Standby mode. By setting bit 10 of the BASICCONFIG register to 1 PCM_ALWAYS_ON is enabled and the LM4930 will continue to drive the PCM clock and sync lines when in Standby mode. This bit should be set if another codec is using the PCM bus. Powerdown mode will disable these outputs. I2S Interface Bus (J2) MIC Jack (J3) This jack is for connection to an external microphone like the kind typically found in mobile phones. Pin 1 is GND, pin 2 is the negative input pin, and pin 3 is the positive pin, with phantom voltage supplied by MIC_BIAS on the LM4930. The I2S standard provides a uni-directional serial interface designed specifically for digital audio. For the LM4930, the interface provides access to a 48kHz, 16 bit full-range stereo audio DAC. This interface uses a three port system of clock (I2S_CLK), data (I2S_DATA), and word (I2S_WS). The clock and word lines can be either master or slave as set by bit 11 in the BASICCONFIG register. A bit clock (I2S_CLK) at 32 or 64 times the sample frequency is established by the I2S system master and a word select (I2S_WS) line is driven at a frequency equal to the sampling rate of the audio data, in this case 48kHz. The word line is registered to change on the negative edge of the bit clock. The serial data (I2S_DATA) is sent MSB first, again registered on the negative edge of the bit clock, delayed by 1 bit clock cycle relative to the changing of the word line (typical I2S format - see Figure 4). The resolution of the I2S interface may be set by modifying the I2S_RES bit (bit 12) in the BASICCONFIG register. If set to 1, the LM4930 operates at 32 bits per frame (3.072MHz). If cleared to 0, then 16 bits per frame is selected (1.536MHz). This has a corresponding effect on the bit clock. The I2S Interface Bus also provides for an additional MCLK connection to an external device from the LM4930 demo board. This may be used in conjunction with National Semiconductors SPDIF- > I2S Conversion Board for quick evaluation. This board features a connection header that inter- IRQ (J4) This pin provides simple status updates from the LM4930 to an external microcontroller if desired. IRQ is logic high when the LM4930 is in a stable state and changes to low when changing modes. This can also be useful for simple software/driver development to monitor mode changes, or as a simple debugging tool. BASIC OPERATION The LM4930 is a highly integrated audio subsystem with many different operating modes available. These modes may be controlled in the BASICCONFIG register in bits 3:0. These mode settings are shown in the BASICCONFIG register table and are described here below: Powerdown Mode (0000b) Part is powered down, analog outputs are not biased. This is a minimum current mode. All part features are shut down. 31 www.national.com LM4930 Application Information LM4930 Application Information Mixed Mode (1010b) (Continued) Part is active. All analog outputs are biased. Audio from the voiceband codec is sent to the mono speaker out. The left channel only of the full range audio is then sent to both the left and right channels of the stereo headphone out. Standby Mode (0001b) The LM4930 is powered down, but outputs are still biased at one half AVDD. This comes at some current cost, but provides a much faster turn-on time with zero "click and pop" transients on the headphone out. Standby mode can be toggled into and out of rapidly and is ideal for saving power whenever continuous audio is not a requirement. All other part functions are suspended unless PCM_ALWAYS_ON (bit 10 in BASICCONFIG register) is enabled, in which case PCM_CLK and PCM_SYNC will continue to function. REGISTERS The LM4930 starts on power-up with all registers cleared in Powerdown mode. Powerdown mode is the recommended time to make setup changes to the digital interfaces (PCM bus, I2S bus). Although the configuration registers can be changed in any mode, changes made during Standby or Powerdown prevent unwanted audio artifacts that may occur during rapid mode changes with the outputs active. The LM4930 also features a soft reset. This reset is enabled by setting bit 4 of the BASICCONFIG register. Mono Speaker Mode (0010b) Part is active. All analog outputs are biased. Audio from the voiceband codec is routed to the mono speaker out. Stereo headphone out is silent. The VOICETESTCONFIG register is used to set various configuration parameters on the voiceband and full-range audio codecs. SIDETONE_ATTEN (bits 4:1) refers to the level of signal from the MIC input that is fed back into the analog audio output path (commonly used in headphone applications and killed in hands-free applications). Setting the AUTOSIDE bit (bit 5) automatically mutes the sidetone in voice over mono speaker modes so feedback isn’t an issue. Quick mute functions are also located in this register, with bits 13:15 muting the mono speaker amp, the headphone amp, and the mic preamp respectively. This register also has a CLOCK_DIV bit (bit 6) which, if set, allows for the use of a 24.576MHz clock instead of the default 12.288MHz. The GAINCONFIG register is used to control the gain of the mono speaker amp , the headphone amp, and the mic preamp. This allows flexible mono speaker gains from -34.5dB to +12dB in 1.5dB steps, headphone amp gains of -46.5dB to 0dB in 1.5dB steps, and mic preamp gains of 17dB to 47dB in 2dB steps. Gain levels may be modified in any mode, but may wait for a zero cross detect in the DAC to eliminate volume control artifacts. This wait for zero cross may be disabled by setting the ZXD_DISABLE bit (bit 7) in the VOICETESTCONFIG register to allow immediate changes. Headphone Call Mode (0011b) Part is active. All analog outputs are biased. Audio from voiceband codec is routed to the stereo headphones. Both left and right channels are the same. Mono speaker out is silent. Conference Call Mode (0100b) Part is active. All analog outputs are biased. Audio from the voiceband codec is routed to the mono speaker out and to the stereo headphones. L+R Mixed to Mono Speaker (0101b) Part is active. All analog outputs are biased. Full-range audio from the 16bit/48kHz audio DAC is mixed together and routed to the mono speaker out. Stereo headphones are silent. Headphone Stereo Audio (0110b) Part is active. All analog outputs are biased. Full-range audio from the 16bit/48kHz audio DAC is sent to the stereo headphone jack. Each channel is heard discretely. The mono speaker is silent. L+R Mixed to Mono Speaker + Stereo Headphone Audio (0111b) Part is active. All analog outputs are biased. Full-range audio from the 16bit/48kHz audio DAC is sent discretely to the stereo headphone jack and also mixed together and sent to the mono speaker out. ANALOG INPUTS AND OUTPUTS The LM4930 features an analog mono BTL output for connection to an 8Ω external speaker. This output can provide up to 1W of power into an 8Ω load with a 5V analog supply. A single-ended stereo headphone output is also featured, providing up to 30mW of power per channel into 32Ω with a 5V analog supply. A Headphone Sense output is provided on J6 for connection to an external controller. This pin goes high when a heaphone is present (when used as shown in Figure 5) and will function in all modes independent of other operations the LM4930 may be currently processing. The MIC Jack input (J3) provides for a low level analog input. Pin 3 provides the power to the MIC and the positive input of the LM4930. Gain for the MIC preamp is set in the GAINCONFIG register. Mixed Mode (1000b) Part is active. All analog outputs are biased. This provides one channel (the left channel) of full range audio to the mono speaker out. Audio from the voiceband codec is then sent to the stereo headphones, the same on each channel. Mixed Mode (1001b) Part is active. All analog outputs are biased. Mixed voiceband and full-range audio (left channel only) is sent to the mono speaker out. Audio from the voiceband codec only is sent to the stereo headphones, the same on each channel. www.national.com 32 inches (millimeters) unless otherwise noted 36-Bump micro SMD Order Number LM4930ITL NS Package Number TLA36KRA X1 = 3.230 ± 0.03mm X2 = 3.408 ± 0.03 X3 = 0.600 ± 0.075 LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Americas Customer Support Center Email: [email protected] Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Support Center Email: [email protected] National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: [email protected] Tel: 81-3-5639-7560 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. LM4930 Audio Subsystem with Stereo Headphone & Mono Speaker Amplifiers Physical Dimensions