www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 FEATURES D Stereo Audio DAC and Mono Audio ADC Support Rates Up to 48 ksps D High Quality 95-dB Stereo Audio Playback Performance D MIC Preamp and Hardware Automatic Gain Control With Up to 59.5-dB Gain D Stereo 16- Headphone Amplifier With Capless Output Option D 400-mW 8- Audio Power Amp With Direct Battery Supply Connection D 32- Differential Earpiece Driver D Integrated PLL For Flexible Audio Clock Generation D Low Power 19-mW Stereo Audio Playback at 48 ksps and 3.3-V Analog Supply level D Programmable Digital Audio Bass/Treble/ EQ/De-Emphasis D Auto-Detection of Jack Insertion, Headset Type, and Button Press D Direct Battery Measurement Accepts Up to 6-V Input D On-Chip Temperature and Auxiliary Input Measurement D Programmable Measurement Converter Resolution, Speed, Averaging, and Timing D SPI and I2S Serial Interfaces D Full Power-Down Control D 48-Pin QFN Package APPLICATIONS D Personal Digital Assistants D Cellular Smartphones D Digital Still Cameras D Digital Camcorders D MP3 Players DESCRIPTION The TLV320AIC28 is a low-power, high-performance audio codec with 16/20/24/32-bit 95-dB stereo playback, mono record functionality at up to 48 ksps. Two microphone inputs include independent programmable bias voltages, built-in pre-amps, and hardware automatic gain control, with single-ended or fully-differential signal input capabilities. The stereo 16-Ω headphone drivers on the AIC28 support capless as well as ac-coupled output configurations. An 8-Ω BTL differential speaker driver provides up to 400 mW of power and 98-dB SNR, while a differential driver is also available for driving a 32-Ω speaker or telephone earpiece. A programmable digital audio effects processor enables bass, treble, midrange, or equalization playback processing. The digital audio data format is programmable to work with popular audio standard protocols (I2S, DSP, left/right justified) in master or slave mode, and also includes an on-chip programmable PLL for flexible clock generation capability. Highly configurable software power control is provided, enabling 48 ksps stereo audio playback to 16-Ω headphones at 19 mW with a 3.3-V analog supply level. The AIC28 offers a 12-bit measurement ADC and internal reference voltage. It includes an on-chip temperature sensor capable of reading 0.3°C resolution, as well as a battery measurement input capable of reading battery voltages up to 6 V, while operating at an analog supply as low as 3 V. The AIC28 is available in a 48-lead 7 x 7 mm QFN package. US Patent No. 624639 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. SPI is a trademark of Motorola, Inc. I2S is a trademark of Philips Corporation. ! " #$%! " &$'(#! )!%* )$#!" # ! "&%##!" &% !+% !%" %," "!$%!" "!)) -!.* )$#! &#%""/ )%" ! %#%""(. #($)% !%"!/ (( &%!%"* Copyright 2004 − 2005, Texas Instruments Incorporated www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. PACKAGE/ORDERING INFORMATION PRODUCT PACKAGE PACKAGE DESIGNATOR OPERATING TEMPERATURE RANGE TLV320AIC28 QFN-48 RGZ −40°C to +85°C ORDERING NUMBER TRANSPORT MEDIA TLV320AIC28IRGZ Rails, 52 TLV320AIC28IRGZR Tape and Reel, 2500 PIN ASSIGNMENTS DVSS DVDD BCLK WCLK SDIN SDOUT MCLK SCLK MISO MOSI SS DAV QFN PACKAGE (TOP VIEW) 48 47 46 45 44 43 42 41 40 39 38 37 IOVDD PWR_DN RESET GPIO2 GPIO1 AVDD2 AVSS2 AVDD1 NC NC NC NC 1 36 2 35 3 34 4 33 5 32 6 31 7 30 8 29 9 28 10 27 11 26 12 25 AVSS1 VREF VBAT AUX2 AUX1 BUZZ_IN CP_OUT CP_IN MICIN_HND MICBIAS_HND MICIN_HED MICBIAS_HED 13 14 15 16 17 18 19 20 21 22 23 24 2 DRVSS2 OUT8P BVDD OUT8N DRVSS1 VGND SPKFC DRVDD SPK2 SPK1 OUT32N MIC_DETECT_IN www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Terminal Functions PIN NAME 1 IOVDD 2 PWR_DN 3 RESET 4 5 DESCRIPTION PIN NAME DESCRIPTION IO Supply 25 MIC_DETECT_IN Microphone detect input Hardware power down 26 OUT32N Hardware reset 27 SPK1 Headset driver output/receiver driver output GPIO2 General purpose IO 28 SPK2 Headset driver output GPIO1 General purpose IO 29 DRVDD Headphone driver power supply 6 AVDD2 PLL analog power supply 30 SPKFC Driver feedback/ speaker detect input 7 AVSS2 Analog ground 31 VGND Virtual ground for audio output 8 AVDD1 Audio ADC, DAC, reference, SAR ADC analog power supply 32 DRVSS1 Driver ground 9 NC No connect 33 OUT8N Loudspeaker driver output 10 NC No connect 34 BVDD Battery power supply 11 NC No connect 35 OUT8P Loudspeaker driver output 12 NC No connect 36 DRVSS2 13 AVSS1 Analog ground 37 DAV 14 VREF Reference voltage for SAR ADC 38 SS 15 VBAT Battery monitor input 39 MOSI SPI Serial data input 16 AUX2 Secondary auxiliary input 40 MISO SPI Serial data output 17 AUX1 First auxiliary input 41 SCLK SPI Serial clock input 18 BUZZ_IN Buzzer input 42 MCLK Master clock 19 CP_OUT Output to cell phone module 43 SDOUT Audio data output 20 CP_IN Input from cell phone module 44 SDIN Audio data input 21 MICIN_HND Handset microphone input 45 WCLK Audio word clock 22 MICBIAS_HND Handset microphone bias voltage 46 BCLK Audio bit clock 23 MICIN_HED Headset microphone input 47 DVDD Digital core supply 24 MICBIAS_HED Headset microphone bias voltage 48 DVSS Digital core and IO ground Receiver driver output Driver ground Auxiliary data available output SPI Slave select input ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted(1), (2) UNITS AVDD1/2 to AVSS1/2 −0.3 V to 3.9 V DRVDD to DRVSS1/2 −0.3 V to 3.9 V BVDD to DRVSS1/2 −0.3 V to 4.5 V IOVDD to DVSS −0.3 V to 3.9 V Digital input voltage to DVSS −0.3 V to IOVDD + 0.3 V Analog input (except VBAT) voltage to AVSS1/2 −0.3 V to AVDD + 0.3 V VBAT input voltage to AVSS1/2 −0.3 V to 6 V AVSS1/2 to DRVSS1/2 to DVSS −0.1 V to 0.1 V AVDD1/2 to DRVDD −0.1 V to 0.1 V Operating temperature range −40°C to 85°C Storage temperature range −65°C to 105°C Junction temperature (TJ Max) Power dissipation QFN package 105°C (TJ Max − TA)/θJA 27°C/W θJA Thermal impedance (with thermal pad soldered to board) Lead temperature Infrared (15 sec) 240°C (1) Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. (2) If the AIC28 is used to drive high power levels to an 8-Ω load for extended intervals at an ambient temperature above 80°C, multiple vias should be used to electrically and thermally connect the thermal pad on the QFN package to an internal heat dissipating ground plane on the user’s PCB. 3 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 ELECTRICAL CHARACTERISTICS At +25°C, AVDD1, AVDD2, DRVDD, IOVDD = 3.3 V, BVDD = 3.9 V, DVDD = 1.8 V, Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted PARAMETER TEST CONDITIONS MIN TYP MAX UNITS BATTERY MONITOR INPUTS Input voltage range 0.5 Input leakage current Battery conversion not selected Accuracy Variation across temperature after system calibration at 4 V battery voltage and room temperature 6.0 V ±1 µA ±15 mV AUXILIARY A/D CONVERTER Resolution Programmable: 8-, 10-,12-bits No missing codes 12-Bit resolution 8 12 Bits 11 Bits Integral nonlinearity −5 5 LSB Offset error −6 6 LSB Gain error −6 6 Noise LSB µVrms 50 VOLTAGE REFERENCE (VREF) VREF output programmed = 2.5 V Voltage range 2.3 VREF output programmed = 1.25 V External reference Reference drift Internal VREF = 1.25 V Current drain Extra current drawn when the internal reference is turned on. 2.5 2.7 V 1.25 1.1 2.5 V 50 ppm/°C 750 µA AUDIO CODEC ADC DECIMATION FILTER CHARACTERISTICS ±0.1 dB −0.25 dB Filter gain at 0.45 Fs −3.0 dB Filter gain at 0.5 Fs −17.5 dB Filter gain from 0 to 0.39 Fs Filter gain at 0.4125 Fs Filter gain from 0.55 Fs to 64 Fs Group delay 4 −75 dB 17/Fs sec www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 ELECTRICAL CHARACTERISTICS (continued) At +25°C, AVDD1, AVDD2, DRVDD, IOVDD = 3.3 V, BVDD = 3.9 V, DVDD = 1.8 V, Int. Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted (continued) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS MICIN_HED 1020 Hz sine wave input, Fs = 48 ksps MICROPHONE INPUT TO ADC Full-scale input voltage (0 dB) 0.707 Input common mode SNR Measured as idle channel noise, 0 dB gain, A-weighted THD 0.63 Vrms input, 0-dB gain PSRR 217 Hz, 100 mV on AVDD1/2(1) 1020 Hz, 100 mV on AVDD1/2(1) Mute attenuation Output code with 0.63 Vrms sine wave input at 1 kHz 80 V 90 dBA −81 −72 dB 55 dB 55 dB 0000H Only ADC on Input resistance Vrms 1.5 ADC and Sidetone on 15 50 kΩ 8 16 kΩ Input capacitance 10 pF HEADSET MICROPHONE BIAS Voltage range PSRR Sourcing current Register 1DH/Page 2, D7−D8=00 3.3 Register 1DH/Page 2, D7−D8=01 2.5 Register 1DH/Page 2, D7−D8=1X 2 217 Hz, 100 mV on AVDD1/2 55 217 Hz, 100 mV on BVDD 74 1020 Hz, 100 mV on AVDD1/2 55 1020 Hz, 100 mV on BVDD 74 Voltage drop <25 mV V dB 5 mA HANDSET MICROPHONE BIAS Voltage range PSRR Sourcing current Register 1DH/Page 2, D6=0 2.5 Register 1DH/Page 2, D6=1 2 217 Hz, 100 mV on AVDD1/2 55 1020 Hz, 100 mV on AVDD1/2 55 Voltage drop <25 mV V dB 5 mA DAC INTERPOLATION FILTER Pass band 20 0.45Fs ±0.06 Pass band ripple Transition band Stop band 0.45Fs 0.5501Fs Hz 7.455Fs Hz Filter group delay De-emphasis error (1) ADC PSRR measurement is calculated as: ǒ VSIG sup V dB 0.5501Fs Stop band attenuation PSRR + 20 log 10 Hz 65 dB 21/Fs Sec ±0.1 dB Ǔ ADCOUT where VSIGsup is the ac signal applied on AVDD1/2, which is 100 mVPP at 1020 Hz, and V ADCOUT + Amplitude of Digital Output Max Possible Digital Amplitude 5 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 ELECTRICAL CHARACTERISTICS (continued) At +25°C, AVDD1, AVDD2, DRVDD, IOVDD = 3.3 V, BVDD = 3.9 V, DVDD = 1.8 V, Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted (continued) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS Load = 16 Ω (single-ended), 50 pF DAC HEADPHONE OUTPUT Full-scale output voltage (0dB) 0.848 Output common mode Vrms 1.5 SNR Measured as idle channel noise, A-weighted THD −1 dBFS Input, 0-dB gain PSRR Interchannel isolation 85 95 −80 dB 1020 Hz, 100 mV on AVDD1/AVDD2/DRVDD(1) 55 dB Coupling from ADC to DAC 80 dB Digital volume control 100 dB 44 mW −63.5 Digital volume control step size Channel separation Between SPK1 and SPK2 DAC SPEAKER OUTPUT Load = 8 Ω (differential), 50 pF Full-scale output voltage (0 dB) Output common mode SNR Measured as idle channel noise, A-weighted THD −1 dBFS Input, 0-dB gain Interchannel isolation dB 55 Per channel PSRR dBA −60 217 Hz, 100 mV on AVDD1/AVDD2/DRVDD(1) Mute attenuation Maximum output power V 90 0 dB −75 dB 1.838 Vrms 1.75 V 98 −74 217 Hz, 100 mV on AVDD1/2 70 217 Hz, 100 mV on BVDD 70 1020 Hz, 100 mV on AVDD1/2 70 1020 Hz, 100 mV on BVDD 70 Coupling from ADC to DAC dB 0.5 dBA −55 dB dB 90 dB Mute attenuation 100 dB Maximum output power 400 mW 0.707 Vrms CELLPHONE 1020-Hz Sine wave input on MICIN_HND, load on CP_OUT = 10 kΩ, 50 pF MIC INPUT TO CPOUT Full-scale input voltage (0 dB) Input common mode 1.5 Full-scale output voltage (0 dB) V 0.707 Output common mode SNR Measured as idle channel noise, A-weighted THD 0 dBFS Input, 0-dB gain 80 Vrms 1.5 V 89 dBA −73 −60 dB 217 Hz, 100 mV on AVDD1/AVDD2/DRVDD 43 PSRR 1020 Hz, 100 mV on AVDD1/AVDD2/DRVDD 43 Interchannel isolation CP_IN to CP_OUT 75 dB Mute attenuation CP_OUT muted 100 dB (1) DAC PSRR measurement is calculated as: ǒ PSRR + 20 log 10 6 VSIG sup V Ǔ SPK1ń2 dB www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 ELECTRICAL CHARACTERISTICS (continued) At +25°C, AVDD1, AVDD2, DRVDD, IOVDD = 3.3 V, BVDD = 3.9 V, DVDD = 1.8 V, Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted (continued) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS 1020-Hz Sine wave input on CP_IN, Load on CP_IN TO 32Ω RECEIVER (SPK1−OUT32N) SPK1−OUT32N = 32 Ω (differential), 50 pF Full-scale input voltage (0 dB) 0.707 Input common mode Vrms 1.5 Full-scale output voltage (0 dB) V 1.697 Output common mode Vrms 1.5 SNR Measured as idle channel noise, A-weighted THD 0 dBFs input, 0 dB gain 85 97 −77 217 Hz, 100 mV on AVDD1/AVDD2/DRVDD 43 PSRR 1020 Hz, 100 mV on AVDD1/AVDD2/DRVDD 43 Interchannel isolation MICIN to RECEIVER Mute attenuation Maximum output power V dBA −60 dB dB 75 dB 100 dB 82 mW DIGITAL INPUT/OUTPUT Logic family Logic level: CMOS VIH VIL VOH VOL Capacitive load IIH = +5 µA IIL = +5 µA 0.7IOVDD IOH = 2 TTL loads IOL = 2 TTL loads 0.8IOVDD V −0.3 0.3IOVDD V V 0.1IOVDD 10 V pF 7 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 ELECTRICAL CHARACTERISTICS (continued) At +25°C, AVDD1, AVDD2, DRVDD, IOVDD = 3.3 V, BVDD = 3.9 V, DVDD = 1.8 V, Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted (continued) PARAMETER TEST CONDITIONS MIN TYP MAX UNITS POWER SUPPLY REQUIREMENTS Power supply voltage AVDD1, AVDD2 3 3.3 3.6 V DRVDD 3 3.3 3.6 V BVDD IOVDD Max MCLK = 100 MHz Max MCLK = 50 MHz DVDD 3 4.2 V 2 3.6 V 1.1 3.6 V 1.95 V 1.65 1.8 IAVDD1 with loudspeaker output (no signal), PLL off 3.1 IBVDD with loudspeaker output (no signal), PLL off 7.5 IAVDD1 with headphone output (no signal), VGND off, PLL off 2.5 IDRVDD with headphone output (no signal), VGND off, PLL off 3.5 IDVDD, PLL off 2.5 mA IAVDD1, headset mic, PLL off 5.2 mA IBVDD, headset mic, PLL off 270 µA IAVDD1, handset mic, PLL off 5.6 mA Digital supply current – mic record only IDVDD, PLL off 1.4 mA Analog supply current IAVDD2, PLL on 1.3 mA Digital supply current IDVDD, PLL on 0.9 mA Hardware power down 27 Only headset/button detection enabled 50 Only auto temperature measurement with 5.59 min delay 50 Headset/button detection and auto temperature measurement with 5.59 min delay 65 IAVDD1 + IAVDD2 66 Analog supply current – audio play back only Digital supply current – audio play back only Analog supply current − mic record only(1) Total current(2) Default current(3) IBVDD (1) Mic record currents measured with no load on MICBIAS. (2) Current measured with MICBIAS_HED voltage programmed to 2 V (Page 2, Register 1DH, BIt D8=1). (3) Default currents measured with device in default mode after reset. 8 mA 9 µA µA A www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 FUNCTIONAL BLOCK DIAGRAM AVDD1 AVDD2 DRVDD BVDD DVDD IOVDD SCLK Battery Monitor VBAT OSC SPI Interface SAR ADC Temperature Measurement SS MOSI MISO DAV VREF MICBIAS_HED MIC_DETECT_IN Internal Reference 2.0/2.5/3.3 To Detection block AGC 2.0/2.5 0 to 59.5dB (0.5dB steps) MICBIAS_HND AUX1 AUX2 MICIN_HED 0 to 59.5dB (0.5dB steps) MICIN_HND RESET 12 to −34.5dB (0.5dB steps) MCLK PWR_DN Σ Σ−∆ ADC SDOUT CP_IN WCLK BUZZ_IN To ADC and DAC 0 to −45dB (3dB steps) 12 to −34.5dB (0.5dB steps) OUT8P OUT32N SPK1 Sidetone Headset detect and Button detect Σ OUT8N PLL −1 Σ−∆ −1 SPK2 SDIN and Serial Interface BCLK Vol Ctl DAC Σ Digital Audio Processing 0 to −63.5dB (0.5dB steps) Σ 0 to −63.5dB (0.5dB steps) CP_OUT SPKFC VGND Σ−∆ Σ Vol Ctl DAC GPIO Interface To Detection block GPIO1 GPIO2 1.5V AVSS1 AVSS2 DRVSS1 DRVSS2 DVSS 9 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 SPI TIMING DIAGRAM /SS S SPISELZ S S SCLK S S SPISELZ S SPICLK MISO S E SPISELZ L t sck tLead t td tLag twsck tf tr twsck tv tho MSB OUT BIT 6 . . . 1 tdis LSB OUT ta MOSI SPISELZ tsu thi MSB IN BIT 6 . . . 1 LSB IN TYPICAL TIMING REQUIREMENTS All specifications typical at 25°C, DVDD = 1.8 V(1) PARAMETER IOVDD = 1.1 V MIN MAX IOVDD = 3.3 V MIN MAX UNITS twsck tLead SCLK Pulse width 30 18 ns Enable Lead Time 18 15 ns tLag ttd Enable Lag Time 18 15 ns Sequential Transfer Delay 18 ta tdis Slave MISO access time 18 15 ns Slave MISO disable time 18 15 ns tsu thi MOSI data setup time 6 6 ns MOSI data hold time 6 6 ns tho tv MISO data hold time 4 4 ns MISO data valid time tr Rise Time tf Fall Time (1) These parameters are based on characterization and are not tested in production. 10 15 ns 25 13 ns 6 4 ns 6 4 ns www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 AUDIO INTERFACE TIMING DIAGRAMS WCLK td(WS) BCLK td(DO−WS) td(DO−BCLK) SDOUT th(DI) ts(DI) SDIN Figure 1. DSP Timing in Master Mode Typical Timing Requirements (see Figure 1) IOVDD = 1.1 V PARAMETER(1) td(WS) td(DO−WS) MIN MIN MAX UNITS WCLK delay 30 15 ns WCLK to DOUT delay (for LJF mode) 30 15 ns 30 15 ns td(DO−BCLK) BCLK to DOUT delay ts(DI) SDIN setup th(DI) tr MAX IOVDD = 3.3 V 6 SDIN hold 6 6 Rise time tf Fall time (1) These parameters are based on characterization and are not tested in production. ns 6 ns 18 6 ns 18 6 ns WCLK td(WS) td(WS) BCLK td(DO−BCLK) SDOUT th(DI) ts(DI) SDIN Figure 2. DSP Timing in Master Mode Typical Timing Requirements (see Figure 2) PARAMETER(1) IOVDD = 1.1 V MIN MAX IOVDD = 3.3 V MIN MAX UNITS td(WS) td(DO−BCLK) WCLK delay 30 15 ns BCLK to DOUT delay 30 15 ns ts(DI) th(DI) SDIN setup 6 6 SDIN hold 6 6 tr Rise time tf Fall time (1) These parameters are based on characterization and are not tested in production. ns ns 18 6 ns 18 6 ns 11 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 WCLK th(WS) BCLK tL(BCLK) tH(BCLK) ts(WS) td(DO−WS) td(DO−BCLK) tP(BCLK) SDOUT th(DI) ts(DI) SDIN Figure 3. I2S/LJF/RJF Timing in Slave Mode Typical Timing Requirements (see Figure 3) PARAMETER(1) IOVDD = 1.1 V MIN MAX IOVDD = 3.3 V MIN MAX UNITS tH(BCLK) tL(BCLK) BCLK high period 40 35 ns BCLK low period 40 35 ns ts(WS) th(WS) WCLK setup 6 6 ns WCLK hold 6 6 ns td (DO−WS) td(DO−BCLK) WCLK to DOUT delay (for LJF mode) 30 18 ns BCLK to DOUT delay 30 15 ns ts(DI) th(DI) SDIN setup 6 SDIN hold 6 tr Rise time tr Fall time (1) These parameters are based on characterization and are not tested in production. 12 6 ns 6 ns 5 4 ns 5 4 ns www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 WCLK th(WS) BCLK ts(WS) th(WS) tL(BCLK) tH(BCLK) ts(WS) td(DO−BCLK) tP(BCLK) SDOUT th(DI) ts(DI) SDIN Figure 4. DSP Timing in Slave Mode Typical Timing Requirements (see Figure 4) PARAMETER(1) IOVDD = 1.1 V MIN MAX IOVDD = 3.3 V MIN MAX UNITS tH(BCLK) tL(BCLK) BCLK high period 40 35 ns BCLK low period 40 35 ns tP(BCLK) ts(WS) BCLK period 80 80 ns WCLK setup 6 6 ns th(WS) td(DO−BCLK) WCLK hold 6 6 ns ts(DI) th(DI) SDIN setup 6 6 ns SDIN hold 6 6 ns BCLK to DOUT delay tr Rise time tf Fall time (1) These parameters are based on characterization and are not tested in production. 30 15 ns 5 4 ns 5 4 ns 13 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 TYPICAL CHARACTERISTICS 1.5 AVDD1/AVDD2 = 3.3 V, TA = 25C, IR = 2.5 V 1 LSB 0.5 0 −0.5 −1 −1.5 500 0 1000 1500 2000 CODE 2500 3000 3500 4000 Figure 5. SAR INL (TA = 25C, Internal Reference = 2.5 V, 12 bit, AVDD1/AVDD2 = 3.3 V) 1 AVDD1/AVDD2 = 3.3 V, TA = 25C, IR = 2.5 V LSB 0.5 0 −0.5 −1 0 500 1000 1500 2000 CODE 2500 3000 3500 4000 Figure 6. SAR DNL (TA = 25C, Internal Reference = 2.5 V, 12 bit, AVDD1/AVDD2 = 3.3 V) 2.4 AVDD1/AVDD2 = 3.3 V, TA = 25C 2.2 2 1.8 Power − mW 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 10 20 30 40 50 60 Sampling Rate − Ksps 70 80 Figure 7. SAR ADC Power Consumption vs Speed (TA = 25C, External Reference, AUX Conversion, AVDD1/AVDD2 = 3.3 V) 14 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 0 AVDD1/AVDD2 = 3.3 V, TA = 25C, −20 −40 dB −60 −80 −100 −120 −140 −160 500 0 1000 1500 2000 2500 3000 3500 4000 f − Frequency − Hz Figure 8. ADC FFT Plot at 8 ksps (TA = 25C, −1 dB, 1 kHz input, AVDD1/AVDD2 = 3.3 V) 0 AVDD1/AVDD2 = 3.3 V, TA = 25C, −20 −40 dB −60 −80 −100 −120 −140 −160 5000 0 10000 15000 f − Frequency − Hz 20000 Figure 9. ADC FFT Plot at 48 ksps (TA = 25C, −1 dB, 1 kHz input, AVDD1/AVDD2 = 3.3 V) 90 AVDD1/AVDD2 = 3.3 V, TA = 25C, 89.5 Dynamic Range − dB 89 88.5 88 87.5 87 86.5 86 8 18 28 38 Sampling Rate − Ksps 48 Figure 10. ADC Dynamic Range vs Sampling Rate (TA = 25C, AVDD1/AVDD2 = 3.3 V) 15 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 20 AVDD1/AVDD2 = 3.3 V, TA = 25C, RL = 16 0 −20 dB −40 −60 −80 −100 −120 −140 −160 0 5000 10000 15000 20000 f − Frequency − Hz Figure 11. DAC FFT Plot (TA = 25C, −1 dB, 1 kHz Input, AVDD1/AVDD2/DRVDD = 3.3 V, RL = 16 Ω) THD − Total Hormonic Distortion − dB −77 AVDD1/AVDD2 = 3.3 V, TA = 25C, RL = 16 −78 −79 −80 −81 −82 −83 −84 5 10 15 20 25 30 Power − mW 35 40 45 Figure 12. THD vs Power on SPK1/2 (TA = 25C, 1 kHz Input, AVDD1/AVDD2/DRVDD = 3.3 V, RL = 16 Ω) 16 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 THD − Total Hormonic Distortion − dB −60 AVDD1/AVDD2/DRDD = 3.3 V, BVDD = 3.9 V TA = 25C, RL = 8 −65 −70 −75 −80 −85 −90 0 50 100 150 200 250 300 350 400 Power − mW Figure 13. THD vs Power on Loudspeaker Driver (TA = 25C, 1 kHz Input, AVDD1/AVDD2/DRVDD = 3.3 V, BVDD = 3.9 V, RL = 8 Ω) 450 Max Power Output − mW 400 350 300 250 200 150 2.7 2.9 3.1 3.3 3.5 3.7 BVDD − V 3.9 4.1 Figure 14. Loudspeaker Driver Output Power vs BVDD (TA = 25C, 1 kHz Input, AVDD1/AVDD2/DRVDD = 3.3 V, RL = 8 Ω, THD v −40 dB) 17 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 OVERVIEW The AIC28 is a highly integrated stereo audio DAC and mono audio ADC for portable computing, communication and entertainment applications. The AIC28 has a register-based architecture where all peripheral functions are controlled through the registers and on-board state machines. The AIC28 consists of the following blocks: D Audio Codec D Headset and Button Detection D Battery Monitors D Auxiliary Inputs D Temperature Monitor Communication to the AIC28 is via a standard SPI serial interface. This interface requires that the Slave Select signal (SS) be driven low to communicate with the AIC28. Data is then shifted into or out of the AIC28 under control of the host microprocessor, which also provides the serial data clock. Control of the AIC28 and its functions is accomplished by writing to different registers in the AIC28. A simple command protocol is used to address the 16-bit registers. Registers control the operation of the SAR ADC and audio codec. OPERATION—AUDIO CODEC AUDIO ANALOG I/O The AIC28 has stereo audio DAC and mono audio ADC. It has a wide range of analog interfaces to support different headsets and analog outputs. The AIC28 has features to interface output drivers (8-Ω, 16-Ω, 32-Ω) and Microphone PGA to Cell-phone. The AIC28 also has a virtual ground (VGND) output, which can be optionally used to connect to the ground terminal of a speaker of headphone to eliminate the ac-coupling capacitor needed at the speaker or headphone output. A special circuit has also been included in the AIC28 to insert a short keyclick sound into the stereo audio output, even when the audio DAC is powered down. They keyclick sound is used to provide feedback to the used when a particular button is pressed or item is selected. The specific sound of the keyclick can be adjusted by varying several register bits that control its frequency, duration, and amplitude. AUDIO DIGITAL I/O INTERFACE Digital audio data samples can be transmitted between the AIC28 and the CPU via the serial bus (BCLK, WCLK, SDOUT, SDIN) that can be configured to transfer digital data in four different formats: Right justified (RJF), Left justified (LJF), I2S and DSP. The four modes are MSB first and operate with variable word length between 16/20/24/32 bits. The AIC28’s audio codec can operate in master or slave mode, depending on the setting of D11 at the register 06h of page 2. The word-select signal (WCLK) and bit clock signal (BCLK) are configured as inputs when the bus is in slave mode (D11 = 0). They are configured as outputs when the bus is in master mode (D11 = 1). Under master mode, both clocks start running when the I2S bus needs to be active (one of the analog input/output paths has been configured and powered up). The WCLK is representative of the sampling rate of the audio ADC/DAC and is synchronized with SDOUT. Although the SDOUT signal can contain two channels of information (a left and right channel), the AIC28 sends the same ADC data in both channels. D ADC/DAC Sampling Rate The audio-control-1 register (Register 00H, Page 2) determines the sampling rates of DAC and ADC. The sampling frequency is scaled down from the reference rate (Fsref). The reference rate is usually either 44.1 kHz or 48 kHz which can be selectable using bit D13 of the register Audio Control 3 (06H/Page2). The ADC and DAC can operate with either common WCLK (equal sampling rates) or separate GPIO1 (For ADC) and WCLK (For DAC) for unequal sampling rates. When the audio codec is powered up, it is by default configured as an I2S slave with both the DAC and ADC operating at Fsref. 18 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 D Word Select Signals The word select signal (WCLK) indicates the channel being transmitted: — WCLK = 0: left channel for I2S mode; — WCLK = 1: right channel for I2S mode. For other modes refer to the timing diagrams below. D Bitclock (BCLK) Signal In addition to being programmable as master or slave mode, the BCLK can also be configured in two transfer modes, 256-S transfer mode and continuous transfer mode, which are described below. These modes are set using bit D12 of control register 06H/page 2. D 256-S Transfer Mode In the 256-S mode, the BCLK rate always equals 256 times the WCLK frequency. In the 256-S mode, the combination of ADC/DAC sampling rate equal to Fsref (as selected by bit D5D0 of control register 00H/page 2) and left-justified mode is not supported. If IOVDD is equal to 1.1 V, then ADC/DAC sampling rate should be less than 39 kHz for all modes except the left justified mode where it should be less than 24 kHz. D Continuous Transfer Mode In the continuous transfer mode, the BCLK rate always equals two-word length times the frequency of WCLK. D Right Justified Mode In right-justified mode, the LSB of left channel is valid on the rising edge of BCLK preceding, the falling edge on WCLK. Similarly the LSB of right channel is valid on the rising edge of BCLK preceding the rising edge of WCLK. 1/fs WCLK BCLK Left Channel SDIN/ SDOUT 0 n MSB n−1 n−2 Right Channel 2 1 0 n n−1 n−2 2 1 0 LSB Figure 15. Timing Diagram for Right-Justified Mode 19 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 D Left Justified Mode In left-justified mode, the MSB of right channel is valid on the rising edge of BCLK, following the falling edge on WCLK. Similarly the MSB of left channel is valid on the rising edge of BCLK following the rising edge of WCLK. 1/fs WCLK BCLK Left Channel SDIN/ SDOUT n n−1 n−2 2 Right Channel 1 0 MSB n n−1 n−2 2 1 0 n n−1 LSB Figure 16. Timing Diagram for Left-Justified Mode D I2S Mode In I2S mode, the MSB of left channel is valid on the second rising edge of BCLK, after the falling edge on WCLK. Similarly the MSB of right channel is valid on the second rising edge of BCLK, after the rising edge of WCLK. 1/fs WCLK BCLK 1 clock before MSB Left Channel SDIN/ SDOUT n n−1 n−2 2 MSB Right Channel 1 0 n n−1 n−2 2 1 0 n LSB Figure 17. Timing Diagram for I2S Mode D DSP Mode In DSP mode, the falling edge of WCLK starts the data transfer with the left channel data first and immediately followed by the right channel data. Each data bit is valid on the falling edge of BCLK. 1/fs WCLK BCLK Left Channel SDIN/ SDOUT 1 0 n n−1 n−2 LSB MSB 2 Right Channel 1 0 n n−1 n−2 2 1 LSB MSB Figure 18. Timing Diagram for DSP Mode 20 0 n n−1 n−2 LSB MSB www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 AUDIO DATA CONVERTERS The AIC28 includes a stereo audio DAC and a mono audio ADC. Both ADC and DAC can operate with a maximum sampling rate of 53 kHz and support all audio standard rates of 8 kHz, 11.025 kHz, 12 kHz, 16 kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, and 48 kHz. By utilizing the flexible clock generation capability and internal programmable interpolation, a wide variety of sampling rates up to 53 kHz can be obtained from many possible MCLK inputs. In addition, the DAC and ADC can independently operate at different sampling rates as indicated in control register 00H/page 2. When the ADC or DAC is operating, the AIC28 requires an applied audio MCLK input. The user should also set bit D13 of control register 06H/page 2 to indicate which Fsref rate is being used. If the codec ADC or DAC is powered up, then the auxiliary ADC uses MCLK and BCLK for its internal clocking, and the internal oscillator is powered down to save power. Typical audio DACs can suffer from poor out-of-band noise performance when operated at low sampling rates, such as 8 kHz or 11.025 kHz. The AIC28 includes programmable interpolation circuitry to provide improved audio performance at such low sampling rates, by first upsampling low-rate data to a higher rate, filtering to reduce audible images, and then passing the data to the internal DAC, which is actually operating at the Fsref rate. This programmable interpolation is determined using bit D5D3 of control register 00H/page 2. For example, if playback of 11.025 kHz data is required, the AIC28 can be configured such that Fsref = 44.1 kHz. Then using bit D5D3 of control register/page 2, the DAC sampling rate (Fs) can be set to Fsref/4, or FS = 11.025 kHz. In operation, the 11.025 kHz digital input data is received by the AIC28, upsampled to 44.1 kHz, and filtered for images. It is then provided to the audio DAC operating at 44.1 kHz for playback. In reality, the audio DAC further upsamples the 44.1 kHz data by a ratio of 128 x and performes extensive interpolation filtering and processing on this data before conversion to a stereo analog output signal. Phase Locked Loop (PLL) The AIC28 has an on chip PLL to generate the needed internal ADC and DAC operational clocks from a wide variety of clocks that may be available in the system. The PLL supports an MCLK varying from 2 MHz to 100 MHz and is register programmable to enable generation of required sampling rates with fine precision. ADC and DAC sampling rates are given by DAC_Fs + Fsref N1 and ADC_Fs + Fsref N2 Where, Fsref must fall between 39 kHz and 53 kHz, and N1, N2=1, 1.5, 2, 3, 4, 5, 5.5, 6 are register programmable. The PLL can be enabled or disabled using register programming. D When PLL is disabled Fsref + MCLK 128 Q Q = 2, 3…17 — Note: For ADC, with N2 = 1.5 or 5.5, odd values of Q are not allowed. — In this mode, the MCLK can operate up to 100 MHz, and Fsref should fall between 39 kHz and 53 kHz. D When PLL is enabled 21 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Fsref + MCLK 2048 K P P = 1, 2, 3 … 8 K = J.D J = 1, 2, 3 ….63 D = 0, 1, 2 … 9999 P, J and D are register programmable.where J is integer part of K before the decimal point, and D is four-digit fractional part of K after the decimal point, including lagging zeros. Examples: If K = 8.5, then J = 8, D = 5000 If K = 7.12, then J = 7, D = 1200 If K = 7.012, then J = 7, D = 120 The PLL is programmed through Registers 1BH and 1CH of Page 2. D When PLL is enabled and D = 0, the following conditions must be satisfied 2 MHz v MCLK v 20 MHz P 80 MHz v MCLK P K v 110 MHz 4Ă v J vĂ 55 D When PLL is enabled D ≠ 0, the following conditions must be satisfied 10 MHz v MCLK v 20 MHz P 80 MHz v MCLK P K v 110 MHz 4Ă v J vĂ 11 Example 1: For MCLK = 12 MHz and Fsref = 44.1 kHz P = 1, K = 7.5264 J = 7, D = 5264 Example 2: For MCLK = 12 MHz and Fsref = 48 kHz P = 1, K = 8.192 J = 8, D = 1920 To externally observe the PLL function, the GPIO2 pin can be set up as the clock monitor (set D2 = 1, register 22h, page 2). Note that besides setting up the PLL and GPIO2, the audio ADC or DAC must be enabled for the PLL output to appear at the GPIO2. Example 1: D Start from power up (with the proper sequence) D Make sure MCLK is provided and /PWR_DWN and /RESET are both high D Set and enable PLL D Connect and power up (do not unmute anything) ADC or DAC or both, for instance: − Page2/Reg03h to C530h or C510h (default is C500h) to connect MICSEL to ADC − Page2/Reg05h to FDFCh (default is FFFCh) to power up ADC. D Set Page2/Reg22h to 0004h to output PLL to GPIO2 pin. 22 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 MONO AUDIO ADC Analog Front End The analog front end of the audio ADC consists of an analog MUX and a programmable gain amplifier (PGA). The MUX can connect either of the Headset Input (MICIN_HED), Handset Input (MICIN_HND), AUX1 and AUX2 signal through the PGA to the ADC for audio recording. The Cell-phone Input (CP_IN) can also be connected to ADC through a PGA at the same time. This enables recording of conversation during a cell-phone call. The AIC28 also has an option of choosing MICIN_HED/MICIN_HND and AUX1/AUX2 as differential input pair. The AIC28 also includes two microphone bias circuits which can source up to 5 mA of current, and are programmable to a 2 V, 2.5 V or 3.3 V level for Headset and 2 V or 3.3 V level for handset. Because of the oversampling nature of the audio ADC and the integrated digital decimation filtering, requirements for analog anti-aliasing filtering are very relaxed. The AIC28 integrates a second order analog anti-aliasing filter with 20-dB attenuation at 1 MHz. This filter, combined with the digital decimal filter, provides sufficient anti-aliasing filtering without requiring any external components. The PGA, for microphone and AUX Inputs, allows analog gain control from 0 dB to 59.5 dB in steps of 0.5 dB. The PGA gain changes are implemented with an internal soft-stepping. This soft-stepping ensures that volume control changes occur smoothly with no audible artifacts. Upon reset, the PGA gain defaults to a mute condition, and upon power down, the PGA soft-steps the volume to mute before shutting down. A read-only flag (D0 control register 04H/Page 2) is set whenever the gain applied by PGA equals the desired value set by the register. The soft-stepping control can be disabled by programming D15=1 in register 1DH of Page 2. When soft stepping is enabled and ADC power down register is written, MCLK should be running to ensure that soft-stepping to mute has completed. MCLK can be shut down once Mic PGA power down flag is set. The PGA, for Cell phone Input (CP_IN) allows gain control from –34.5 dB to 12 dB in steps of 0.5 dB. The PGA gain changes are implemented with an internal soft−stepping. This soft-stepping ensures that volume control changes occur smoothly with no audible artifacts. Upon reset, the PGA gain defaults to a mute condition, and upon power down, the PGA soft-steps the volume to mute before shutting down. A read−only flag (D7 control register 1FH/Page 2) is set whenever the gain applied by PGA equals the desired value set by the register. The soft-stepping control can be disabled by the programming D12=1 in register 1DH of Page 2. When soft-stepping is enabled and ADC power down register is written, MCLK should be running to ensure that soft-stepping to mute has completed. MCLK can be shut down once Cell PGA power down flag is set. Delta-Sigma ADC The analog-to-digital converter has a delta-sigma modulator with a 128 times oversampling ratio. The ADC can support maximum output rate of 53 kHz. Decimation Filter The audio ADC includes an integrated digital decimation filter that removes high frequency content and downsamples the audio data from an initial sampling rate of 128 times Fs to the final output sampling rate of Fs. The decimation filter provides a linear phase output response with a group delay of 17/Fs. The –3 dB bandwidth of the decimation filter extends to 0.45 Fs and scales with the sample rate (Fs). Programmable High Pass Filter The ADC channel has a programmable high-pass filter whose cutoff frequency can be programmed through control register. By default the high pass filter is off. The high-pass filter is a first order IIR filter. This filter can be used to remove the DC component of the input signal and offset of the ADC channel. Automatic Gain Control (AGC) The AIC28 includes Automatic gain control (AGC) for Microphone Inputs (MICIN_HED or MICIN_HND) and Cell-phone input (CP_IN). AGC can be used to maintain nominally constant output signal amplitude when recording speech signals. This circuitry automatically adjusts the PGA gain as the input signal becomes overly loud or very weak, such as when a person speaking into a microphone moves closer or farther from the microphone. The AGC algorithm has several programmable settings, including target gain, attack and decay time constants, noise threshold, and max PGA applicable that allow the algorithm to be fine tuned for any particular application. The algorithm uses the absolute average of the signal (which is the average of the absolute value of the signal) as a measure of the nominal amplitude of the output signal. 23 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Target gain represents the nominal output level at which the AGC attempts to hold the ADC output signal level. The AIC28 allows programming of eight different target gains, which can be programmed from –5.5 dB to –24 dB relative to a full-scale signal. Since the AIC28 reacts to the signal absolute average and not to peak levels, it is recommended that the target gain be set with enough margin to avoid clipping at the occurrence of loud sounds. Attack time determines how quickly the AGC circuitry reduces the PGA gain when the input signal is too loud. It can be varied from 8 ms to 20 ms. Decay time determines how quickly the PGA gain is increased when the input signal is too low. It can be varied in the range from 100 ms to 500 ms. Noise threshold is the minimum amplitude for the input signal that the AGC considers as a valid signal. If the average amplitude of the incoming signal falls below this value, the AGC considers it as silence and brings down the gain to 0 dB in steps of 0.5 dB for every FS. This will also set the noise threshold flag. The gain stays at 0 dB until the average amplitude of the input signal rises above the noise threshold value. This ensures that noise does not get amplified in the absence of a valid input speech signal. Noise threshold level is programmable from −30dB to −90 dB for microphone input, and from −30 dB to −60 dB for cell-phone input. When AGC Noise Threshold is set to −70 dB, −80 dB, or −90 dB, the microphone input Max PGA applicable setting must be greater than or equal to 11.5 dB, 21.5 dB, or 31.5 dB respectively. This operation includes debounce and hysteresis to avoid the AGC gain from cycling between high gain and 0 dB when the signal amplitude is near the noise threshold level. When the noise threshold flag is set, status of gain applied by AGC and saturation flag should be ignored. Maximum input gain applicable allows user to restrict maximum gain applied by the AGC. This can be used for limiting PGA gain in situations where environment noise is greater than programmed noise threshold. Microphone input Max PGA can be programmed from 0 dB to 59.5 dB in steps of 0.5 dB. Cell-phone input Max PGA can be programmed from −34.5 dB to −0.5 dB in steps of 0.5 dB, as well as +12 dB. See Table 1 for various AGC programming options. AGC can be used only if microphone input or Cell-phone input is routed to the ADC channel. When both microphone input and Cell-phone input are connected to the ADC, AGC is automatically disabled. Input Signal Target Gain Output Signal AGC Gain Decay Time Figure 19. AGC Characteristics 24 Attack Time www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Table 1. AGC Settings MIC HEADSET INPUT BIT CONTROL REGISTER AGC enable D0 Target gain Time constants (attack and decay time) MIC HANDSET INPUT CELL-PHONE INPUT BIT CONTROL REGISTER BIT CONTROL REGISTER 01H D0 1EH D0 24H D7−D5 01H D7−D5 1EH D7−D5 24H D4−D1 01H D4−D1 1EH D4−D1 24H D13−D11 24H D13−D11 24H D13−D11 24H D11 04H D11 04H D14 24H Hysteresis D10−D9 1DH D10−D9 1DH D10−D9 24H Debounce time (normal to silence mode) D8−D6 26H D8−D6 26H D8−D6 27H Debounce time (silence to normal mode) D5−D3 26H D5−D3 26H D5−D3 27H Max PGA applicable D15−D9 26H D15−D9 26H D15−D9 27H Gain applied by AGC D15−D8 01H D15−D8 1EH D14−D8 1FH D0 04H D0 04H D7 1FH D3 06H D8 24H Noise threshold Noise threshold flag Saturation flag Clip stepping disable D3 06H NOTE: All settings shown in Table 1 are located in Page 2 of control registers. Stereo Audio DAC Each channel of the stereo audio DAC consists of a digital audio processing block, a digital interpolation filter, digital delta-sigma modulator, and an analog reconstruction filter. The DAC is designed to provide enhanced performance at low sample rates through increased oversampling and image filtering, thereby keeping quantization noise generated within the delta-sigma modulator and signal images strongly suppressed within the audio band to beyond 20 kHz. This is realized by keeping the upsampled rate constant at 128 x Fsref and changing the oversampling ratio as the input sample rate is changed. For Fsref of 48 kHz, the digital delta−sigma modulator always operates at a rate of 6.144 MHz. This ensures that quantization noise generated within the delta-sigma modulator stays within the frequency band below 20 kHz at all sample rates. Similarly, for Fsref rate of 44.1 kHz, the digital delta-sigma modulator always operates at a rate of 5.6448 MHz. Digital Audio Processing The DAC channel consists of optional filters for de-emphasis and bass, treble, midrange level adjustment, or speaker equalization. The de-emphasis function is only available for sample rates of 32 kHz, 44.1 kHz, and 48 kHz. The transfer function consists of a pole with time constant of 50ms and a zero with time constant of 15ms. Frequency response plots are given in the Audio Codec Filter Frequency Responses section of this data sheet. The DAC digital effects processing block consists of a fourth order digital IIR filter with programmable coefficients (one set per channel). The filter is implemented as cascade of two biquad sections with frequency response given by: ǒ Ǔǒ N0 ) 2 N1 z *1 ) N2 z *2 32768 * 2 D1 z *1 * D2 z *2 Ǔ N3 ) 2 N4 z *1 ) N5 z *2 32768 * 2 D4 z *1 * D5 z *2 The N and D coefficients are fully programmable, and the entire filter can be enabled or bypassed. The coefficients for this filter implement a variety of sound effects, with bass-boost or treble boost being the most commonly used in portable audio applications. The default N and D coefficients in the part are given by: N0 = N3 = 27619 N1 = N4 = −27034 N2 = N5 = 26461 D1 = D4 = 32131 D2 = D5 = −31506 25 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 These coefficients implement a shelving filter with 0 dB gain from dc to approximately 150 Hz, at which point it rolls off to 3 dB attenuation for higher frequency signals, thus giving a 3-dB boost to signals below 150 Hz. The N and D coefficients are represented by 16−bit twos complement numbers with values ranging from –32768 to +32767. Frequency response plots are given in the Audio Codec Filter Frequency Responses section of this data sheet. Interpolation Filter The interpolation filter upsamples the output of the digital audio processing block by the required oversampling ratio. It provides a linear phase output with a group delay of 21/Fs. In addition, the digital interpolation filter provides enhanced image filtering to reduce signal images caused by the upsampling process that are below 20 kHz. For example, upsampling an 8-kHz signal produces signal images at multiples of 8 kHz, i.e., 8 kHz, 16 kHz, 24 kHz, etc. The images at 8 kHz and 16 kHz are below 20 kHz and still audible to the listener, therefore, they must be filtered heavily to maintain a good quality output. The interpolation filter is designed to maintain at least 65 dB rejection of images that land below 7.455 Fs. In order to utilize the programmable interpolation capability, the Fsref should be programmed to a higher rate (restricted to be in the range of 39 kHz to 53 kHz when the PLL is in use), and the actual FS is set using the dividers in bits D5D3 of control register 00H/page 2. For example, if Fs = 8 kHz is required, then Fsref can be set to 48 kHz, and the DAC Fs set to Fsref/6. This ensures that all images of the 8-kHz data are sufficiently attenuated well beyond a 20-kHz audible frequency range. Passband ripple for all sample-rate cases (from 20 Hz to 0.45 Fs) is +0.06 dB maximum. Delta-Sigma DAC The audio digital-to-analog converter incorporates a third order multi-bit delta-sigma modulator followed by an analog reconstruction filter. The DAC provides high-resolution, low−noise performance, using oversampling and noise shaping techniques. The analog reconstruction filter design consists of a 6 tap analog FIR filter followed by a continuous time RC filter. The analog FIR operates at 6.144 MHz (128x48 kHz, for Fsref of 48 kHz) or at 5.6448 MHz (128x44.1 kHz, for Fsref of 44.1 kHz). The DAC analog performance may be degraded by excessive clock jitter on the MCLK input. Therefore, care must be taken to keep jitter on this clock to a minimum (less than 50ps). DAC Digital Volume Control The DAC has a digital volume control block, which implements programmable gain. The volume level can be varied from 0 dB to –63.5 dB in 0.5 dB steps, in addition to a mute bit, independently for each channel. The volume level of both channels can also be changed simultaneously by the master volume control. The gain is implemented with a soft−stepping algorithm, which only changes the actual volume by one step per input sample, either up or down, until the desired volume is reached. The rate of soft-stepping can be slowed to one step per two input samples through D1 of control register 04H/Page 2. Because of soft-stepping, the host does not know when the DAC has been completely muted. This may be important if the host wishes to mute the DAC before making a significant change, such as changing sample rates. In order to help with this situation, the part provides a flag back to the host via a read-only register bit (D2−D3 of control register 04H/page 2) that alerts the host when the part has completed the soft-stepping, and the actual volume has reached the desired volume level. The soft-stepping feature can be disabled by programming D14=1 in register 1DH in Page 2. If soft-stepping is enabled, the MCLK signal should be kept applied to the device, until the DAC power-down flag is set. When this flag is set, the internal soft-stepping process and power down sequence is complete, and the MCLK can be stopped if desired. The AIC28 also includes functionality to detect when the user switches on or off the de-emphasis or digital audio processing functions, then (1) soft-mute the DAC volume control, (2) change the operation of the digital effects processing and (3) soft-unmute the part. This avoids any possible pop/clicks in the audio output due to instantaneous changes in the filtering. A similar algorithm is used when first powering up or down the DAC. The circuit begins operation at power-up with the volume control muted, then soft-steps it up to the desired volume level. At power-down, the logic first soft-steps the volume down to a mute level, then powers down the circuitry. 26 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 DAC Powerdown The DAC powerdown flag (D4D3 of control register 05H/page 2) along with D10 of control register 05H/page 2 denotes the powerdown status of the DAC according to Table 2. Table 2. DAC Powerdown Status D10, D4, D3 POWERUP/POWERDOWN STATE OF DAC 0,0,0 DAC left and right are in stable powerup state. 0,0,1 DAC left is in stable powerup state. DAC right is in the process of powering up. The length of this state is determined by PLL and output driver powerup delays controlled by register programming. 0,1,0 DAC left is in the process of powering up. The length of this state is determined by PLL and output driver powerup delays controlled by register programming. DAC right is in stable powerup state. 0,1,1 DAC left and right are in the process of powering up. The length of this state is determined by PLL and output driver powerup delays controlled by register programming. 1,0,0 DAC left and right are in the process of powering down. The length of this state is determined by soft−stepping of volume control block. 1,0,1 DAC left is in the process of powering down. The length of this state is determined by soft−stepping of volume control block. DAC right is in stable powerdown state. 1,1,0 DAC left is in stable powerdown state. DAC right is in the process of powering down. The length of this state is determined by soft−stepping of volume control block. 1,1,1 DAC left and right are in stable powerdown state. Analog Outputs The AIC28 has the capability to route the DAC output to any of the selected analog outputs. The AIC28 provides various analog routing capabilities. All analog outputs other than the selected ones are powered down for optimal power consumption. D Headphone Drivers The AIC28 features stereo headphone drivers (SPK1 and SPK2) that can deliver 44 mW per channel at 3.3-V supply, into 16-Ω loads. The AIC28 provides flexibility to connect either of the DAC channels to either of the headphone driver outputs. It also allows mixing of signals from different DAC channels. The headphones can be connected in a single ended configuration using ac-coupling capacitors, or the capacitors can be removed and virtual ground (VGND) powered for a cap-less output connection. Note that the VGND amplifier must be powered up if the cap-less configuration is used. In the case of an ac-coupled output, the value of the capacitors is typically chosen based on the amount of low−frequency cut that can be tolerated. The capacitor in series with the load impedance forms a high-pass filter with –3 dB cutoff frequency of 1/(2πRC) in Hz, where R is the impedance of the headphones. Use of an overly small capacitor reduces low-frequency components in the signal output and lead to low-quality audio. When driving 16-Ω headphones, capacitors of 220-µF (a commonly used value) result in a high-pass filter cutoff frequency of 45 Hz, although reducing these capacitors to 50 µF results in a cutoff frequency of 199 Hz, which is generally considered noticeable when playing music. The cutoff frequency is reduced to half of the above values if 32-Ω headphones are used instead of 16-Ω. The AIC28 programmable digital effects block can be used to help reduce the size of capacitors needed by implementing a low frequency boost function to help compensate for the high-pass filter introduced by the ac-coupling capacitors. For example, by using 50-µF capacitors and setting the AIC28 programmable filter coefficients as shown below, the frequency response can be improved as shown in Figure 21. Filter coefficients (use the same for both channels): N0 = 32767, N1 = −32346, N2 = 31925, N3 = 32767, N4 = 0, N5 = 0 D0 = 32738, D1 = −32708, D4 = 0, D5 =0 27 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 0 −2 −4 Gain − dB −6 −8 −10 −12 −14 −16 −18 −20 0 200 400 600 f − Frequency − Hz 800 1000 Figure 20. Uncompensated Response For 16-Ω Load and 50-F Decoupling Capacitor 0 −2 −4 Gain − dB −6 −8 −10 −12 −14 −16 −18 −20 0 200 400 600 f − Frequency − Hz 800 1000 Figure 21. Frequency Response For 16-Ω Load and 50-F Decoupling Capacitor After Gain Compensation Using Above Set of Coefficients For Audio Effects Filter Using the capless output configuration eliminates the need for these capacitors and removes the accompanying high-pass filter entirely. However, this configuration does have one drawback – if the RETURN terminal of the headphone jack (which is wired to the AIC28 VGND pin) is ever connected to a ground that is shorted to the AIC28 ground pin, then the VGND amplifier enters short-circuit protection, and the audio output does not function properly. The AIC28 incorporates a programmable short-circuit detection/protection function. In case of short circuit, all analog outputs are disabled and a read only bit D1 of control register 1DH/page 2 is set. In such cases, there are two ways to return to normal operation: − Hardware or software reset − Power down all the output drivers, which can be achieved by setting bits D12, D11, D 8, D7, and D6 of control register 05H/page 2 and then wait for driver power down status flags (bits D15−D10 of control register 25H/page 2) to become 1. The wait time is typically less than 50 ms after which, output drivers can be programmed as desired. 28 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 For the cap interface, this feature can be disabled by setting bit D0 of control register 20H/page 2. In the case of the cap-less interface, VGND short circuit protection must also be disabled, which can be achieved by setting bit D4 of control register 21H/page 2. The AIC28 implements a pop reduction scheme to reduce audible artifacts during powerup and powerdown of headphone drivers. The scheme can be controlled by programming bits D5 and D4 of control register 25H/page 2. By default, the driver pop reduction scheme is enabled and can be disabled by programming bit D5 of control register 25H/page 2 to 1. When this scheme is enabled and the virtual ground connection is not used (VGND amplifier is powered down), the audio output driver slowly charges up any external ac-coupling capacitors to reduce audible artifacts. Bit D4 of control register 25H/page 2 provides control of the charging time for the ac-coupling capacitor as either 0.8 sec or 4 sec. When the virtual ground amplifier is powered up and used, the external ac-coupling capacitor is eliminated, and the powerup time becomes 1 ms. This scheme takes effect whenever any of the headphone drivers are powered up. D Speaker Driver The AIC28 has an integrated speaker driver (OUT8P−OUT8N) capable of driving an 8 Ω differential load. The speaker driver, powered directly from the battery supply (3.5 V to 4.2 V) on the BVDD pin can deliver 400 mW at 3.9 V supply. It allows connecting one or both DAC channel to speaker driver. The AIC28 also has a short circuit protection feature for the speaker driver which can be enabled by setting bit D5 of control register 21H/page 2. D Receiver Driver The AIC28 includes a receiver driver (SPK1−OUT32N), which can drive a 32 Ω differential load. It is capable of delivering 82 mW into a 32 Ω load. The AIC28 does not allow both the receiver driver and headphone drivers to be turned on at the same time. Also, when the receiver driver is being used, the headphone driver load must be disconnected. Headset Interface The AIC28 supports all standard headset interfaces. It is capable of interfacing with 3-wire stereo headset, 3-wire cellular headset and 4-wire stereo-cellular headsets. It supports both capacitor-coupled (cap) and capacitor-less (capless) interface for headset through software programming. D Capless Interface Figure 22 shows the connection diagram to the AIC28 for capless interface. VGND acts as a ground of headset jack. Voltage at VGND is 1.5 V and MICBIAS_HED voltage is programmed to 3.3 V. With this, the voltage across microphone is configured to be 1.8 V. In order to minimize the effect of routing resistance on VGND inside the device and on the printed circuit board (PCB), SPKFC should be shorted to VGND at the jack. This reduces crosstalk from speaker to microphone because of common ground as VGND. 29 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 MICBIAS_HND 2.5 MICIN_HND OUT8P LOUDSPEAKER OUT8N MICBIAS_HED MIC_DETECT_IN Stereo Cellular g g s m s m To Detection block s RECEIVER g 3.3V MICIN_HED OUT32N Stereo + Cellular −1 s s −1 SPK1 SPK2 m = mic s = stere g = ground/midbias SPKFC VGND Figure 22. Connection Diagram for Capless Interface D Cap Interface Figure 23 shows connection diagram to device for cap interface. 30 To Detection block 1.5 V www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 MICBIAS_HND 2.5V MICIN_HND OUT8P LOUDSPEAKER OUT8N MICBIAS_HED MIC_DETECT_IN Stereo Cellular g g s m s g m 2.5V To Detection block MICIN_HED s RECEIVER Stereo + Cellular −1 s s m = mic s = stere g = ground/midbias OUT32N −1 SPK1 SPK2 SPKFC VGND To Detection block 1.5 V Figure 23. Connection Diagram for Cap Interface D Auto Detection The AIC28 has built in monitors to automatically detect the insertion and removal of headsets. The detection scheme can differentiate between stereo, cellular and stereo-cellular headsets. Upon detection of headset insertion or removal, the AIC28 updates read-only bit D12 of control register 22H/Page 2. The AIC28 can be programmed to send an active high interrupt for insertion and removal of headsets to the host-processor over GPIO1 using bit D3 of control register 22H/Page 2 and GPIO2 using bit D4 of control register 22H/Page 2. The headset detection feature can be enabled by setting bit D15 of control register 22H/Page 2. When headset detection is enabled and headset is not detected, SPK1, VGND and MICBIAS_HED are turned off irrespective of control register settings. The AIC28 also has the capability to detect button press on the headset microphone. It consumes less than 50 µA while waiting for button press with everything else powered down. Upon button press, the AIC28 updates read-only bit D11 of control register 22H/Page 2. It can also send an active high interrupt for indicating button press to the processor over GPIO1 using bit D1D0 of control register 22H/Page 2. The AIC28 provides debounce programmability for headset and button detect. Debounce programmability can be used to reject glitches generated, and hence avoids false detection, while inserting headset or pressing button. Figure 24 shows terminal connections and jack configuration required for various headsets. Care should be taken to avoid any dc path from MIC_DETECT_IN to ground, when a headset is not inserted. 31 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 s s s g g g s s m m Stereo + Cellular g m s s Cellular g m s Stereo g s s Figure 24. Connection Diagram for Jacks D Headset Detection − Interrupt polarity: Active high. − Typical interrupt duration: 1.75 ms. − Debounce programmability on bits D10 and D9 in control register 22H/Page 2: − 00 => 16 ms duration (with 2 ms clock resolution) − 01 => 32 ms duration (with 4 ms clock resolution) − 10 => 64 ms duration (with 8 ms clock resolution) − 11 => 128 ms duration (with 16 ms clock resolution) − Headset detect flag is available till headset is connected. D Button Detection − Interrupt polarity: Active high. − Typical interrupt duration: Button pressed time + clock resolution. Clock resolution depends upon debounce programmability. − Typical interrupt delay from button: Debounce duration + 0.5ms − Debounce programmability: − 00 => No glitch rejection − 01 => 8 ms duration (with 1 ms clock resolution) − 10 => 16 ms duration (with 2 ms clock resolution) − 11 => 32 ms duration (with 4 ms clock resolution) − Button detect flag is set when button is pressed. It gets clear when flag read is done after button press removal. AUDIO ROUTING Audio Interface for Smart-Phone Applications The AIC28 supports audio routing features to combine various analog inputs and route them to analog outputs or the ADC for smart−phone applications. In smart-phone applications, the AIC28 can be used to interface the cell-phone module to microphones and speakers. The AIC28 allows the input from the cell-phone module to be routed to different speakers through a PGA which supports a range of 12 dB to –34.5 dB in steps of 0.5 dB. The cell-phone input can also be mixed with the microphone input for recording through the ADC. The microphone or DAC audio can be routed to the cell-phone output. The buzzer input from cell-phone can be routed to the speakers through a PGA. The buzzer input supports PGA range of 0 dB to –45 dB in steps of 3 dB. The mixing and PGA are under full software control. The mixing feature can be used even when both ADC and DAC are powered down. Cell-phone PGA, microphone PGA and buzzer PGA includes soft-stepping logic. Soft-stepping logic works on Fsref if DAC is powered up otherwise; it works on internal oscillator clocks. 32 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Analog Mixer The analog mixer can be used to route the analog input selected for the ADC through an analog volume control and then mix it with the audio DAC output. The analog mixer feature is available only if the single ended microphone input or the AUX input is selected as the input to the ADC, not when the ADC input is configured in fully-differential mode. This feature is available even if the ADC and DAC are powered down. The analog volume control has a range from +12 dB to –34.5 dB in 0.5 dB steps plus mute and includes soft−stepping logic. The internal oscillator is used for soft−stepping whenever the ADC and DAC are powered down. Keyclick A special circuit has been included for inserting a square−wave signal into the analog output signal path based on register control. This functionality is intended for generating keyclick sounds for user feedback. Register 04H/Page 2 contains bits that control the amplitude, frequency, and duration of the square−wave signal. The frequency of the signal can be varied from 62.5 Hz to 8 kHz and its duration can be programmed from 2 periods to 32 periods. Whenever this register is written, the square wave is generated and coupled into the audio output. The keyclick enable bit D15 of control register 04H/Page 2 is reset after the duration of a keyclick is played out. This capability is available even when the ADC and DAC are powered down. OPERATION—AUXILIARY MEASUREMENT Auxiliary ADC Converter The auxiliary analog inputs (battery voltage monitor, chip temperature, and auxiliary inputs) are provided via a multiplexer to the successive approximation register (SAR) analog-to-digital (A/D) converter. The ADC architecture is based on capacitive redistribution architecture, which inherently includes a sample/hold function. The ADC is controlled by an ADC control register. Several modes of operation are possible, depending upon the bits set in the control register. Channel selection, scan operation, averaging, resolution, and conversion rate may all be programmed through this register. These modes are outlined in the sections below for each type of analog input. The results of conversions made are stored in the appropriate result register. Data Format The AIC28 output data is in unsigned Binary format and can be read from registers over the SPI interface. Reference The AIC28 has an internal voltage reference that can be set to 1.25 V or 2.5 V, through the reference control register. The internal reference voltage should only be used in the single-ended mode for battery monitoring, temperature measurement, and for utilizing the auxiliary inputs. An external reference can also be applied to the VREF pin, and the internal reference can be turned off. Variable Resolution The AIC28 provides three different resolutions for the ADC: 8, 10 or 12 bits. Performing the conversions at lower resolution reduce the amount of time it takes for the ADC to complete its conversion process, which lowers power consumption. Conversion Clock and Conversion Time The AIC28 contains an internal 8 MHz clock, which is used to drive the state machines inside the device that perform the many functions of the part. This clock is divided down to provide a clock to run the ADC. The division ratio for this clock is set in the ADC control register. The ability to change the conversion clock rate allows the user to choose the optimal value for resolution, speed, and power. If the 8 MHz clock is used directly, the ADC is limited to 8-bit resolution; using higher resolutions at this speed does not result in accurate conversions. Using a 4 MHz conversion clock is suitable for 10-bit resolution; 12-bit resolution requires that the conversion clock run at 1 or 2 MHz. Regardless of the conversion clock speed, the internal clock runs nominally at 8 MHz. The conversion time of the AIC28 is dependent upon several functions. While the conversion clock speed plays an important role in the time it takes for a conversion to complete, a certain number of internal clock cycles are needed for proper 33 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 sampling of the signal. Moreover, additional times, such as the panel voltage stabilization time, can add significantly to the time it takes to perform a conversion. Conversion time can vary depending upon the mode in which the AIC28 is used. Throughout this data sheet, internal and conversion clock cycles are used to describe the times that many functions take to execute. Considering the total system design, these times must be taken into account by the user. When both the audio ADC and DAC are powered down, the auxiliary ADC uses an internal oscillator for conversions. However, to save power whenever audio ADC or DAC are powered up, the internal oscillator is powered down and MCLK and BCLK are used to clock the auxiliary ADC. The AIC28 uses the programmed value of bit D13 in control register 06H/page 2 and the PLL programmability to derive a clock from MCLK. The various combinations are listed in Table 3. Table 3. Conversion Clock Frequency D13=0 (in control register 06H/page 2) D13=1 (in control register 06H/page 2) PLL enabled MCLK × K ×13 P ×160 MCLK × K ×17 P ×192 PLL disabled MCLK ×13 Q ×10 MCLK ×17 Q ×12 Temperature Measurement In some applications, such as battery charging, a measurement of ambient temperature is required. The temperature measurement technique used in the AIC28 relies on the characteristics of a semiconductor junction operating at a fixed current level. The forward diode voltage (VBE) has a well-defined characteristic versus temperature. The ambient temperature can be predicted in applications by knowing the 25°C value of the VBE voltage and then monitoring the variation of that voltage as the temperature changes. The AIC28 offers two modes of temperature measurement. The first mode requires a single reading to predict the ambient temperature. A diode, as shown in Figure 25, is used during this measurement cycle. This voltage is typically 600 mV at +25°C with a 20-µA current through it. The absolute value of this diode voltage can vary a few millivolts. The temperature coefficient of this voltage is typically 2 mV/°C. During the final test of the end product, the diode voltage at a known room temperature should be stored in nonvolatile memory. Further calibration can be done to calculate the precise temperature coefficient of the particular. This method has a temperature resolution of approximately 0.3°C/LSB and accuracy of approximately ±2°C with two-temperature calibration. Figure 26 and Figure 27 shows typical plots with single and two-temperature calibration respectively. X+ MUX A/D Converter Temperature Select TEMP0 TEMP1 Figure 25. Functional Block Diagram of Temperature Measurement Mode 34 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 10 Error in Measurement − °C 8 6 4 2 0 −2 −4 −6 −8 −10 −40 −20 0 20 40 60 80 100 TA − Free-Air Temperature − C Figure 26. Typical Plot of Single Measurement Method After Calibrating for Offset at Room Temperature 0.20 Error in Measurement − °C 0 −0.20 −0.40 −0.60 −0.80 −1 −1.20 −40 −20 0 20 40 60 TA − Free-Air Temperature − C 80 100 Figure 27. Typical Plot of Single Measurement Method After Calibrating for Offset and Gain At Two Temperatures The second mode uses a two-measurement (differential) method. This mode requires a second conversion with a current 82 times larger. The voltage difference between the first (TEMP1) and second (TEMP2) conversion, using 82 times the bias current, is represented by: kT q ln(N) where: N is the current ratio = 82 k = Boltzmann’s constant (1.38054 • 10−23 electrons volts/degrees Kelvin) q = the electron charge (1.602189 • 10−19 °C) T = the temperature in degrees Kelvin The equation for the relation between differential code and temperature may vary slightly from device to device and can be calibrated at final system test by the user. This method provides resolution of approximately 1.5°C/LSB and accuracy of approximately ±4°C after calibrating at room temperature. 35 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 4 Error in Measurement − °C 3 2 1 0 −1 −2 −3 −4 −40 −20 0 20 40 60 TA − Free-Air Temperature − C 80 100 Figure 28. Typical Plot of Differential Measurement Method After Calibrating for Offset at Room Temperature The AIC28 supports programmable auto-temperature measurement mode, which can be enabled using control register 0CH/page 1. In this mode, the AIC28 can auto-start the temperature measurement after a programmable interval. The user can program minimum and maximum threshold values through a register. If the measurement goes outside the threshold range, the AIC28 sets a flag in the read only control register 0CH/page 1, which gets cleared after the flag is read. The AIC28 can also be configured to send and active high interrupt over GPIO1 by setting D9 in control register 0CH/page 1. The duration of the interrupt is approximately 2 ms. Battery Measurement An added feature of the AIC28 is the ability to monitor the battery voltage on the other side of a voltage regulator (dc/dc converter), as shown in Figure 29. The battery voltage can vary from 0.5 V to 6 V while maintaining the analog supply voltage to the AIC28 at 3.0 V to 3.6 V. The input voltage (VBAT) is divided down by a factor of 5 so that a 6.0 V battery voltage is represented as 1.2 V to the ADC. In order to minimize the power consumption, the divider is only on during the sampling of the battery input. If the battery conversion results in A/D output code of B, the voltage at the battery pin can be calculated as: V BAT + BN 2 5 VREF Where: N is the programmed resolution of A/D VREF is the programmed value of internal reference or the applied external reference. 36 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 LDO or DC-DC Converter Battery 0.5 to 6 V 3.0 V to 3.6 V + − VDD R VBAT ADC 8 kΩ 2 kΩ Figure 29. Battery Measurement Functional Block Diagram See the section Conversion Time Calculation for the AIC28 in this data sheet for timing diagrams and conversion time calculations. For increased protection and robustness, TI recommends a minimum 100−Ω resistor be added in series between the system battery and the VBAT pin. The 100-Ω resistor will cause an approximately 1% gain change in the battery voltage measurement, which can easily be corrected in software when the battery conversion data is read by the operating system. Auxiliary Measurement The auxiliary voltage inputs (AUX1 and AUX2) can be measured in much the same way as the battery inputs except the difference that input voltage is not divided. Applications might include external temperature sensing, ambient light monitoring for controlling the backlight, or sensing the current drawn from the battery. The auxiliary input can also be monitored continuously in scan mode. The AIC28 provides feature to measure resistance using auxiliary inputs. It has two modes of operation: (1) External bias resistance measurement (2) Internal bias resistance measurement. Internal bias resistance measurement mode does not need an external bias resistance of 50 kΩ, but provides less accuracy because of on chip resistance variation, which is typically ±20%. Figure 30 shows connection diagram for resistance measurement mode on AUX1. VREF VREF 50 kΩ 50 kΩ 50 kΩ AUX1 Vsar SAR AUX1 Vsar SAR R R a. Internal bias, Resistance Measurement b. External bias, Resistance Measurement Figure 30. Connection DIagram for Resistance Measurement Resistance can be calculated using following formula: R + 50 KW Vsar VREF * Vsar Where: 37 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 VREF is the SAR ADC reference Vsar is input to the SAR ADC The AIC28 supports programmable auto−auxiliary measurement mode, which can be enabled using control register 0CH/page 1. In this mode, the AIC28 can auto start the auxiliary measurement after a programmable interval. The user can program minimum and maximum threshold values through a register. If the measurement goes outside the threshold range, the AIC28 sets a flag in the read only control register 0CH/page 1, which gets cleared after the flag is read. The AIC28 can also be configured to send an active high interrupt over GPIO1 by setting D9 of control register 0CH/page 1. The duration of the interrupt is approximately 2 ms. See the section Conversion Time Calculation for the AIC28 in this data sheet for timing diagram and conversion time calculation Port Scan If making measurements of VBAT, AUX1, and AUX2 is desired on a periodic basis, the Port Scan mode can be used. This mode causes the AIC28 to sample and convert battery input and both auxiliary inputs. At the end of this cycle, the battery and auxiliary result registers contain the updated values. Thus, with one write to the AIC28, the host can cause three different measurements to be made. See the section Issues at the end of this data sheet for details of a known issue with this mode. See the section Conversion Time Calculation for the AIC28 and subsection Port Scan Operation in this data sheet for timing diagrams and conversion time calculations. Buffer Mode The AIC28 supports a programmable buffer mode, which is applicable auxiliary (BAT, AUX1, AUX2, TEMP1, TEMP2). Buffer mode is implemented using a circular FIFO with a depth of 64. The number of interrupts required to be serviced by a host processor can be reduced significantly buffer mode. Buffer mode can be enabled using control register 02H/page1. Figure 31. Circular Buffer Converted data is automatically written into the FIFO. To control the writing, reading and interrupt process, a write pointer (WRPTR), a read pointer (RDPTR) and a trigger pointer (TGPTR) are used. The read pointer always shows the location, which will be read next. The write pointer indicates the location, in which the next converted data is going to be written. The trigger pointer indicates the location at which an interrupt will be generated if the write pointer reaches that location. Trigger level is the number of the data points needed to be present in the FIFO before generating an interrupt. Figure 31 shows the case when trigger level is programmed as 32. On resetting buffer mode, RDPTR moves to location 1, WRPTR moves to location 1, and TGPTR moves to location equal to programmed trigger level. 38 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 The user can select the input or input sequence, which needs to be converted, from the ADCSM bits of control register 00H/page 1. The converted values are written in a predefined sequence to the circular buffer. The user has flexibility to program a specific trigger level in order to choose the configuration which best fits the application. When the number of converted data, written in FIFO, becomes equal to the programmed trigger level then the device generates an interrupt signal on DAV pin. Buffer mode can be used in single-shot conversion or continuous conversion mode. In single shot conversion mode, once the number of data written reaches programmed trigger level, the AIC28 generates an interrupt and waits for the user to start reading. As soon as the user starts reading the first data from the last converted set, the AIC28 clears the interrupt and starts a new set of conversions and the trigger pointer is incremented by the programmed trigger level. An interrupt is generated again when the trigger condition is satisfied. In continuous conversion mode, once number of data written reaches the programmed trigger level, the AIC28 generates an interrupt. It immediately starts a new set of conversions and the trigger pointer is incremented by the programmed trigger level. An interrupt gets cleared either by writing the next converted data into the FIFO or by starting to read from the FIFO. See the section Conversion Time Calculation for the AIC28 and subsection Buffer Mode Operation in this data sheet for timing diagrams and conversion time calculations. Depending upon how the user is reading data, the FIFO can become empty or full. If the user is trying to read data even if the FIFO is empty, then RDPTR keeps pointing to same location. If the FIFO gets full then the next location is overwritten with newly converted data and the read pointer is incremented by one. While reading the FIFO, the AIC28 provides FIFO empty and full status flags along with the data. The user can also read a status flag from control register 02H/page 1. DIGITAL INTERFACE RESET The device requires reset after power up. This requires a low-to-high transition on the RESET pin after power up for correct operation. Reset initializes all the internal registers, counters and logic. Hardware Power-Down Hardware power-down powers down all the internal circuitry to save power. All the register contents are maintained. General Purpose I/O The AIC28 has two general purpose I/O (GPIO1 and GPIO2), which can be programmed either as inputs or outputs. As outputs they can be programmed to control external logic through the AIC28 registers or send interrupts to the host processor on events like button detect, headset insertion, headset removal, Auxiliary/temperature outside threshold range etc. As inputs they can be used by the host-processor to monitor logic states of signals on the system through the AIC28 registers. SPI Digital Interface All AIC28 control registers are programmed through a standard SPI bus. The SPI allows full-duplex, synchronous, serial communication between a host processor (the master) and peripheral devices (slaves). The SPI master generates the synchronizing clock and initiates transmissions. The SPI slave devices depend on a master to start and synchronize transmissions. A transmission begins when initiated by a master SPI. The byte from the master SPI begins shifting in on the slave MOSI pin under the control of the master serial clock. As the byte shifts in on the MOSI pin, a byte shifts out on the MISO pin to the master shift register. The idle state of the serial clock for the AIC28 is low, which corresponds to a clock polarity setting of 0 (typical microprocessor SPI control bit CPOL = 0). The AIC28 interface is designed so that with a clock phase bit setting of 1 (typical microprocessor SPI control bit CPHA = 1), the master begins driving its MOSI pin and the slave begins driving its MISO pin on the first serial clock edge. The SS pin can remain low between transmissions; however, the AIC28 only interprets command words which are transmitted after the falling edge of SS. 39 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 AIC28 COMMUNICATION PROTOCOL Register Programming The AIC28 is entirely controlled by registers. Reading and writing these registers is controlled by an SPI master and accomplished by the use of a 16-bit command, which is sent prior to the data for that register. The command is constructed as shown in Figure 32. The command word begins with an R/W bit, which specifies the direction of data flow on the SPI serial bus. The following 4 bits specify the page of memory this command is directed to, as shown in Table 4. The next six bits specify the register address on that page of memory to which the data is directed. The last five bits are reserved for future use and should be written only with zeros. Table 4. Page Addressing PG3 PG2 PG1 PG0 0 0 0 0 PAGE ADDRESSED 0 0 0 0 1 1 0 0 1 0 2 0 0 1 1 3 0 1 0 0 Reserved 0 1 0 1 Reserved 0 1 1 0 Reserved 0 1 1 1 Reserved 1 0 0 0 Reserved 1 0 0 1 Reserved 1 0 1 0 Reserved 1 0 1 1 Reserved 1 1 0 0 Reserved 1 1 0 1 Reserved 1 1 1 0 Reserved 1 1 1 1 Reserved To read all the first page of memory, for example, the host processor must send the AIC28 the command 0x8000 – this specifies a read operation beginning at page 0, address 0. The processor can then start clocking data out of the AIC28. The AIC28 automatically increments its address pointer to the end of the page; if the host processor continues clocking data out past the end of a page, the AIC28 sends back the value 0xFFFF. Likewise, writing to page 1 of memory would consist of the processor writing the command 0x0800, which specifies a write operation, with PG0 set to 1, and all the ADDR bits set to 0. This results in the address pointer pointing at the first location in memory on page 1. See the section on the AIC28 memory map for details of register locations. BIT 15 MSB BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8 BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 LSB R/W* PG3 PG2 PG1 PG0 ADDR5 ADDR4 ADDR3 ADDR2 ADDR1 ADDR0 0 0 0 0 0 Figure 32. AIC28 Command Word SS SCLK MOSI COMMAND WORD DATA Figure 33. Register Write Opration 40 DATA www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 SS SCLK MOSI COMMAND WORD MOSO DATA DATA Figure 34. Register Read Operation AIC28 Memory Map The AIC28 has several 16-bit registers which allow control of the device as well as providing a location for results from the AIC28 to be stored until read by the host microprocessor. These registers are separated into four pages of memory in the AIC28: a data page (page 0), control pages (page 1 and page 2) and a buffer data page (page 3). The memory map is shown in Table 5. Table 5. Memory Map PAGE 0: AUXILIARY DATA REGISTER ADDR REGISTER PAGE 1: AUXILIARY CONTROL REGISTERS ADDR REGISTER PAGE 3: BUFFER DATA REGISTERS PAGE 2: AUDIO CONTROL REGISTERS ADDR REGISTER ADDR REGISTER 00 Reserved 00 AUX ADC 00 Audio Control 1 00 Buffer Location 01 Reserved 01 Status 01 Headset PGA Control 01 Buffer Location 02 Reserved 02 Buffer Mode 02 DAC PGA Control 02 Buffer Location 03 Reserved 03 Reference 03 Mixer PGA Control 03 Buffer Location 04 Reserved 04 Reset Control Register 04 Audio Control 2 04 Buffer Location 05 BAT 05 Configuration 05 Power Down Control 05 Buffer Location 06 Reserved 06 Temperature Max 06 Audio Control 3 06 Buffer Location 07 AUX1 07 Temperature Min 07 Digital Audio Effects Filter Coefficients 07 Buffer Location 08 AUX2 08 AUX1 Max 08 Digital Audio Effects Filter Coefficients 08 Buffer Location 09 TEMP1 09 AUX1 Min 09 Digital Audio Effects Filter Coefficients 09 Buffer Location 0A TEMP2 0A AUX2 Max 0A Digital Audio Effects Filter Coefficients 0A Buffer Location 0B Reserved 0B AUX2 Min 0B Digital Audio Effects Filter Coefficients 0B Buffer Location 0C Reserved 0C Measurement Configuration 0C Digital Audio Effects Filter Coefficients 0C Buffer Location 0D Reserved 0D Programmable Delay 0D Digital Audio Effects Filter Coefficients 0D Buffer Location 0E Reserved 0E Reserved 0E Digital Audio Effects Filter Coefficients 0E Buffer Location 0F Reserved 0F Reserved 0F Digital Audio Effects Filter Coefficients 0F Buffer Location 10 Reserved 10 Reserved 10 Digital Audio Effects Filter Coefficients 10 Buffer Location 11 Reserved 11 Reserved 11 Digital Audio Effects Filter Coefficients 11 Buffer Location 12 Reserved 12 Reserved 12 Digital Audio Effects Filter Coefficients 12 Buffer Location 13 Reserved 13 Reserved 13 Digital Audio Effects Filter Coefficients 13 Buffer Location 14 Reserved 14 Reserved 14 Digital Audio Effects Filter Coefficients 14 Buffer Location 15 Reserved 15 Reserved 15 Digital Audio Effects Filter Coefficients 15 Buffer Location 16 Reserved 16 Reserved 16 Digital Audio Effects Filter Coefficients 16 Buffer Location 17 Reserved 17 Reserved 17 Digital Audio Effects Filter Coefficients 17 Buffer Location 18 Reserved 18 Reserved 18 Digital Audio Effects Filter Coefficients 18 Buffer Location 19 Reserved 19 Reserved 19 Digital Audio Effects Filter Coefficients 19 Buffer Location 1A Reserved 1A Reserved 1A Digital Audio Effects Filter Coefficients 1A Buffer Location 41 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 PAGE 0: AUXILIARY DATA REGISTER ADDR PAGE 1: AUXILIARY CONTROL REGISTERS REGISTER ADDR PAGE 3: BUFFER DATA REGISTERS PAGE 2: AUDIO CONTROL REGISTERS REGISTER ADDR REGISTER ADDR REGISTER 1B Reserved 1B Reserved 1B PLL Programmability 1B Buffer Location 1C Reserved 1C Reserved 1C PLL Programmability 1C Buffer Location 1D Reserved 1D Reserved 1D Audio Control 4 1D Buffer Location 1E Reserved 1E Reserved 1E Handset PGA Control 1E Buffer Location 1F Reserved 1F Reserved 1F Cell & Buzzer PGA Control 1F Buffer Location 20 Reserved 20 Reserved 20 Audio Control 5 20 Buffer Location 21 Reserved 21 Reserved 21 Audio Control 6 21 Buffer Location 22 Reserved 22 Reserved 22 Audio Control 7 22 Buffer Location 23 Reserved 23 Reserved 23 GPIO Control 23 Buffer Location 24 Reserved 24 Reserved 24 AGC−CP_IN Control 24 Buffer Location 25 Reserved 25 Reserved 25 Driver Powerdown Status 25 Buffer Location 26 Reserved 26 Reserved 26 Mic AGC control 26 Buffer Location 27 Reserved 27 Reserved 27 Cell-phone AGC Control 27 Buffer Location 28 Reserved 28 Reserved 28 Reserved 28 Buffer Location 29 Reserved 29 Reserved 29 Reserved 29 Buffer Location 2A Reserved 2A Reserved 2A Reserved 2A Buffer Location 2B Reserved 2B Reserved 2B Reserved 2B Buffer Location 2C Reserved 2C Reserved 2C Reserved 2C Buffer Location 2D Reserved 2D Reserved 2D Reserved 2D Buffer Location 2E Reserved 2E Reserved 2E Reserved 2E Buffer Location 2F−3F Reserved 2F−3F Reserved 2F−3F Buffer Locations 2F−3F Reserved AIC28 Control Registers This section describes each of the registers shown in the memory map of Table 5. The registers are grouped according to the function they control. Note that in the AIC28, bits in control registers may refer to slightly different functions depending upon if you are reading the register or writing to it. AIC28 Data Registers (Page 0) The data registers of the AIC28 hold data results from conversion of auxiliary ADC. All of these registers default to 0000H upon reset. These registers are read only. BAT, AUX1, AUX2, TEMP1 and TEMP2 Registers The results of all ADC conversions are placed in the appropriate data register. The data format of the result word, R, of these registers is right-justified, as follows: 42 Bit 15 MSB Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 LSB 0 0 0 0 R11 MSB R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 LSB www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 PAGE 1 CONTROL REGISTER MAP REGISTER 00H: Auxiliary ADC Control BIT NAME D15 RESET VALUE READ/ WRITE FUNCTION 0 R D14 ADST 1(for read) 0 (for write) R/W Reserved. The value of this bit should always be set to zero. ADC STATUS. READ 0 =>ADC is busy 1 => ADC is not busy (default). WRITE 0 => Normal mode (default). 1 => Stop conversion and power down. D13−D10 ADCSM 0000 R/W ADC Scan Mode. 0000 => No scan 0001 => Reserved 0010 => Reserved 0011 => Reserved 0100 => Reserved 0101 => Reserved 0110 => BAT input is converted and the results returned to the BAT data register. 0111 => AUX2 input is converted and the results returned to the AUX2 data register 1000 => AUX1 input is converted and the results returned to the AUX1 data register. 1001 => Auto Scan function: For AUX1, AUX2, TEMP1 or TEMP2 as chosen using control register 0CH/page 1. Scan continues until stop bit is sent or D13−D10 are changed. 1010 => TEMP1 input is converted and the results returned to the TEMP1 data register. 1011 => Port scan function: BAT, AUX1, AUX2 inputs are measured and the results returned to the appropriate data registers. 1100 => TEMP2 input is converted and the results returned to the TEMP2 data register. 1101 => Reserved 1110 => Reserved 1111 => Reserved D9−D8 RESOL 00 R/W Resolution Control. The ADC resolution is specified with these bits. 00 => 12-bit resolution 01 => 8-bit resolution 10 => 10-bit resolution 11 => 12-bit resolution D7−D6 ADAVG 00 R/W Converter Averaging Control. These two bits allow user to specify the number of averages the converter will perform selected by bit D0, which selects either Mean Filter or Median Filter. Mean Filter Median Filter 00 => No average No average 01 => 4-data average 5-data average 10 => 8-data average 9-data average 11 => 16-data average 15-data average D5−D4 ADCR 00 R/W Conversion Rate Control. These two bits specify the internal clock rate, which the ADC uses to control performing a single conversion. These bits are the same whether reading or writing. tconv + N ) 4 ƒ INTCLK Where fINTCLK is the internal clock frequency. For example, with 12-bit resolution and a 2 MHz internal clock frequency, the conversion time is 8 µs. This yields an effective throughput rate of 125 kHz. 00 => 8 MHz internal clock rate (use for 8-bit resolution only) 01 =>4 MHz internal clock rate (use for 8-bit/10-bit resolution only) 10 =>2 MHz internal clock rate 11 =>1 MHz internal clock rate D3−D1 D0 AVGFS 0’s R 0 R/W Reserved Average Filter Select 0 => Mean Filter 1 => Median Filter 43 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 01H: Status Register BIT NAME RESET VALUE READ/ WRITE D15−D14 DAV 10 R/W D13 PWRDN 0 R ADC Power down status 0 => ADC is active 1 => ADC stops conversion and powers down 0 R Reserved 0 R Data Available Status 0 => No data available. 1 => Data is available(i.e one set of conversion is done) Note:− This bit gets cleared only after all the converted data have been completely read out. This bit is not valid in case of buffer mode. 0 R Reserved 0 R BAT Data Register Status 0 => No new data is available in BAT data register 1 => New data is available in BAT data register D12 D11 DAVAIL D10−D7 D6 BSTAT FUNCTION Data Available. These two bits program the function of the DAV pin. 00 => Reserved 01 => Acts as data available (active low) only. The DAV goes low as soon as one set of ADC conversion(s) is completed. For scan mode, DAV remains low as long as all the appropriate registers have not been read out. 10 => Reserved 11 => Reserved Note:− D15−D14 should be rpogrammed to 01 for the AIC28 to operate properly. Note: This bit gets cleared only after the converted data of BAT has been completely read out of the register. This bit is not valid in case of buffer mode. D5 D4 AX1STAT 0 R Reserved 0 R AUX1 Data Register Status 0 => No new data is available in AUX1−data register 1 => New data is available in AUX1−data register Note: This bit gets cleared only after the converted data of AUX1 has been completely read out of the register. This bit is not valid in case of buffer mode. D3 AX2STAT 0 R AUX2 Data Register Status 0 => No new data is available in AUX2−data register 1 => New data is available in AUX2−data register Note: This bit gets cleared only after the converted data of AUX2 has been completely read out of the register. This bit is not valid in case of buffer mode. D2 T1STAT 0 R TEMP1 Data Register Status 0 => No new data is available in TEMP1−data register 1 => New data is available in TEMP1−data register Note: This bit gets cleared only after the converted data of TEMP1 has been completely read out of the register. This bit is not valid in case of buffer mode. D1 T2STAT 0 R TEMP2 Data Register Status 0 => No new data is available in TEMP2−data register 1 => New data is available in TEMP2−data register Note: This bit gets cleared only after the converted data of TEMP2 has been completely read out of the register. This bit is not valid in case of buffer mode. D0 44 0 R Reserved www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 02H: Buffer Control BIT NAME RESET VALUE READ/ WRITE D15 BUFRES 0 R/W Buffer Reset. 0 => Buffer mode is disabled and RDPTR, WRPTR & TGPTR set to their reset value. 1 => Buffer mode is enabled. D14 BUFCONT 0 R/W Buffer Mode Selection 0 => Continuous conversion mode. 1 => Single shot mode. D13−D11 BUFTL 000 R/W Trigger Level TL selection of Buffer used for SAR ADC 000 => 8 001 => 16 010 => 24 011 => 32 100 => 40 101 => 48 110 => 56 111 => 64 D10 BUFOVF 0 R Buffer Full Flag 0 => Buffer is not full. 1 => Buffer is full. This means buffer contains 64 unread converted data. D9 BUFEMF 1 R Buffer Empty Flag 0 => Buffer is not empty. 1 => Buffer is empty. This means there is no unread converted data in the buffer. 0’s R Reserved D8−D0 FUNCTION REGISTER 03H: Reference Control BIT NAME RESET VALUE READ/ WRITE FUNCTION D15−D6 0’s R D5 0 R/W Reserved Reserved. Always write 0 to this bit. D4 VREFM 0 R/W Voltage Reference Mode. This bit configures the VREF pin as either external reference or internal reference. 0 => External reference 1 => Internal reference D3−D2 RPWUDL 00 R/W Reference Power Up Delay. These bits allow for a delay time for measurements to be made after the reference powers up, thereby assuring that the reference has settled 00 => 0 µs 01 => 100 µs 10 => 500 µs 11 => 1000 µs Note: This will be valid only when device is programmed for internal reference and Bit D1 = 1, i.e., reference is powered down between the conversions if not required. D1 RPWDN 1 R/W Reference Power Down. This bit controls the power down of the internal reference voltage. 0 => Powered up at all times. 1 => Powered Down between conversions. Note: When D4 = 0 i.e. device is in external reference mode then the internal reference is powered down always. D0 IREFV 0 R/W Internal Reference Voltage. This bit selects the internal voltage for AUX ADC. 0 => VREF = 1.25 V 1 => VREF = 2.50 V 45 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 04H: Reset Control BIT NAME RESET VALUE READ/ WRITE D15−D0 RSALL R/W FFFFH FUNCTION Reset All. Writing the code 0xBB00, as shown below, to this register causes the AIC28 to reset all its control registers to their default, power−up values. 1011101100000000 => Reset all control registers Others => Do not write other sequences to the register. REGISTER 05H: Reserved BIT NAME D15−D0 RESET VALUE READ/ WRITE 0’s R FUNCTION Reserved REGISTER 06H: Temperature Max Threshold Measurement BIT NAME D15−D13 RESET VALUE READ/ WRITE FUNCTION 0’s R D12 TMXES 0 R/W Reserved Max Temperature (TEMP1 or TEMP2) threshold check enable for Auto/Non−Auto−Scan Measurement. 0 => Max Temperature threshold check is disabled. 1 => Max Temperature threshold check is enabled. Only valid for TEMP1 or TEMP2. Depends on bit TSCAN of control register 0CH/page 1 in case of auto−scan measurement and depends on bits ADCSM of control register 00H/page 1 in case of non−auto−scan measurementa D11−D0 TTHRESH FFFH R/W Temperature Max Threshold. When code due to temperature measurement goes above or equal to programmed threshold value, interrupt is generated. REGISTER 07H: Temperature Min Threshold Measurement BIT NAME D15−D13 RESET VALUE READ/ WRITE 0’s R FUNCTION Reserved D12 TMNES 0 R/W Min Temperature (TEMP1 or TEMP2) threshold check enable for Auto/Non−Auto−Scan Measurement. 0 => Min Temperature threshold check is disabled. 1 => Min Temperature threshold check is enabled. Only valid for TEMP1 or TEMP2. Depends on bit TSCAN of control register 0CH/page 1 in case of auto−scan measurement and depends on bits ADCSM of control register 00H/page 1 in case of non−auto−scan measurement. D11−D0 TTHRESL 000H R/W Temperature Min Threshold. When code due to temperature measurement goes below or equal to programmed threshold value, interrupt is generated. REGISTER 08H: AUX1 Max Threshold Measurement BIT NAME D15−D13 RESET VALUE READ/ WRITE FUNCTION 0’s R D12 A1MXES 0 R/W Max AUX1 threshold check enable for Auto/Non−Auto−Scan Measurement. 0 => Max AUX1 threshold check is disabled. 1 => Max AUX1 threshold check is enabled. D11−D0 A1THRESH FFFH R/W AUX1 Threshold. When code due to AUX1 measurement goes above or equal to programmed threshold value, interrupt is generated. 46 Reserved www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 09H: AUX1 Min Threshold Measurement BIT NAME D15−D13 RESET VALUE READ/ WRITE FUNCTION 0’s R D12 A1MNES 0 R/W Reserved Min AUX1 threshold check enable for Auto/Non−Auto−Scan Measurement. 0 => Min AUX1 threshold check is disabled. 1 => Min AUX1 threshold check is enabled. D11−D0 A1THRESL 000H R/W AUX1 Threshold. When code due to AUX1 measurement goes below or equal to programmed threshold value, interrupt is generated. REGISTER 0AH: AUX2 Max Threshold Measurement BIT NAME RESET VALUE D15−D13 READ/ WRITE FUNCTION 0’s R D12 A2MXES 0 R/W Reserved Max AUX2 threshold check enable for Auto/Non−Auto−Scan Measurement. 0 => Max AUX2 threshold check is disabled. 1 => Max AUX2 threshold check is enabled. D11−D0 A1THRESH FFFH R/W AUX2 Threshold. When code due to AUX2 measurement goes above or equal to programmed threshold value, interrupt is generated. REGISTER 0BH: AUX2 Max Threshold Measurement BIT NAME D15−D13 RESET VALUE READ/ WRITE 0’s R FUNCTION Reserved D12 A2MNES 0 R/W Min AUX2 threshold check enable for Auto/Non−Auto−Scan Measurement. 0 => Min AUX2 threshold check is disabled. 1 => Min AUX2 threshold check is enabled. D11−D0 A2THRESL 000H R/W AUX2 Threshold. When code due to AUX2 measurement goes below or equal to programmed threshold value, interrupt is generated. 47 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 0CH: Measurement Configuration BIT NAME RESET VALUE READ/ WRITE D15 TSCAN 0 R/W TEMP Configuration when Auto−Temperature is selected 0 => TEMP1 is used for auto−temperature function 1 => TEMP2 is used for auto−temperature function D15 A1CONF 0 R/W AUX1 Configuration. 0 => AUX1 is used for voltage measurement. 1 => AUX1 is used for resistance measurement. D14 A2CONF 0 R/W AUX2 Configuration. 0 => AUX2 is used for voltage measurement. 1 => AUX2 is used for resistance measurement. D12 ATEMES 0 R/W Auto Temperature (TEMP1 or TEMP2) measurement enable 0 => Auto temperature measurement is disabled. 1 => Auto temperature measurement is enabled. TEMP1 or TEMP2 selection is depends on TSCAN bit. D11 AA1MES 0 R/W Auto AUX1 measurement enable 0 => Auto AUX1 measurement is disabled. 1 => Auto AUX1 measurement is enabled. D10 AA2MES 0 R/W Auto AUX2 measurement enable 0 => Auto AUX2 measurement is disabled. 1 => Auto AUX2 measurement is enabled. D9 IGPIO1 0 R/W Enable GPIO1 for Auto/Non−Auto−Scan interrupt (this programmability is valid only if D11 & D9 of control register 23H/page 2 are 0’s) 0 => GPIO1 is not selected for interrupt. 1 => GPIO1 is used to send an interrupt. Interrupt is generated when any of TEMP (TEMP1 or TEMP2), AUX1 or AUX2 are not passing threshold D8 THMXFL 0 R Max threshold flag for Temperature (TEMP1 or TEMP2) measurement. 0 => Temperature measurement is less than max threshold setting. 1 => Temperature measurement is greater than or equal to max threshold setting. D7 THMNFL 0 R Min threshold flag for Temperature (TEMP1 or TEMP2) measurement. 0 => Temperature measurement is greater than min threshold setting. 1 => Temperature measurement is less than or equal to max threshold setting. D6 A1HMXFL 0 R Max threshold flag for AUX1measurement. 0 => AUX1 measurement is less than max threshold setting. 1 => AUX1 measurement is greater than or equal to max threshold setting. D5 A1HMNFL 0 R Min threshold flag for AUX1 measurement. 0 => AUX1 measurement is greater than min threshold setting. 1 => AUX1 measurement is less than or equal to max threshold setting. D4 A2HMXFL 0 R Max threshold flag for AUX2measurement. 0 => AUX2 measurement is less than max threshold setting. 1 => AUX2 measurement is greater than or equal to max threshold setting. D3 A2HMNFL 0 R Min threshold flag for AUX2 measurement. 0 => AUX2 measurement is greater than min threshold setting. 1 => AUX2 measurement is less than or equal to max threshold setting. D2 EXTRES 0 R/W 0’s R D1−D0 48 FUNCTION External Bias Resistance Measurement mode 0 => Internal bias resistance measurement mode is enabled. 1 => External bias resistance measurement mode is enabled. Reserved www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 0DH: Programmable Delay In-Between Continuous Conversion BIT NAME RESET VALUE READ/ WRITE D15 NTSPDELEN 0 R/W Programmable delay for auxiliary auto measurement mode 0 => Programmable delay is disabled for auxiliary auto measurement mode. 1 => Programmable delay is enabled for auxiliary auto measurement mode. D14−D12 NTSPDINTV 010 R/W Programming delay in−between conversion for auxiliary auto measurement mode 000 => 1.12 min 001 => 3.36 min 010 => 5.59 min 011 => 7.83 min 100 => 10.01 min 101 => 12.30 min 110 => 14.54 min 111 => 16.78 min Note: These delays are from end of one set of conversion to the start of another set of conversion. D11−D8 FUNCTION 0’s R D7 CLKSEL 0 R/W Reserved Clock selection for the auxiliary converter 0 => Internal oscillator clock is selected. 1 => External MCLK is selected. Note: External clock is used only to control the delay programmed in between the conversion. D6−D0 CLKDIV 0000001 R/W Clock Division used to divide MCLK for getting 1 MHz clock for programmable delay, i.e. MCLK/CLKDIV = 1 MHz, 0000000 => 128, 0000001 => 1, 0000010 => 2, …… 1111110 => 126, 1111111 => 127 REGISTER 0EH: Reserved BIT NAME RESET VALUE READ/ WRITE D15−D8 RESV FFh R/W FUNCTION Reserved. Write only FFh to these bits. 49 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 PAGE 2 CONTROL REGISTER MAP REGISTER 00H: Audio Control 1 BIT NAME RESET VALUE READ/ WRITE D15−D14 ADCHPF 00 R/W D13−D12 FUNCTION ADC High Pass Filter 00 => Disabled 01 => −3db point = 0.0045xFs 10 => −3dB point = 0.0125xFs 11 => −3dB point = 0.025xFs Note: Fs is ADC sample rate 0’s R D11−D10 WLEN 00 R/W Codec Word Length 00 => Word length = 16−bit 01 => Word length = 20−bit 10 => Word length = 24−bit 11 => Word length = 32−bit D9−D8 DATFM 00 R/W Digital Data Format 00 => I2S Mode 01 => DSP Mode 10 => Right Justified 11 => Left Justified Note: Right justified valid only when the ratio between DAC and ADC sample rate is an integer. e.g. ADC = 32 kHz and DAC = 24 kHz or vice−versa is invalid for right justified Mode. 0’s R D7−D6 Reserved Reserved D5−D3 DACFS 000 R/W DAC Sampling Rate 000 => DAC FS = Fsref/1 001 => DAC FS = Fsref/(1.5) 010 => DAC FS = Fsref/2 011 => DAC FS = Fsref/3 100 => DAC FS = Fsref/4 101 => DAC FS = Fsref/5 110 => DAC FS = Fsref/(5.5) 111 => DAC FS = Fsref/6 Note: Fsref is set between 39 kHz and 53 kHz D2−D0 ADCFS 000 R/W ADC Sampling Rate 000 => ADC FS = Fsref/1 001 => ADC FS = Fsref/(1.5) 010 => ADC FS = Fsref/2 011 => ADC FS = Fsref/3 100 => ADC FS = Fsref/4 101 => ADC FS = Fsref/5 110 => ADC FS = Fsref/(5.5) 111 => ADC FS = Fsref/6 Note: Fsref is set between 39 kHz and 53 kHz 50 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 01H: Gain Control for Headset/Aux Input BIT NAME RESET VALUE READ/ WRITE D15 ADMUT_HED 1 R/W Headset/Aux Input Mute 1 => Headset/Aux Input Mute 0 => Headset/Aux Input not muted Note: If AGC is enabled and Headset/Aux Input is selected then ADMUT_HED+ADPGA_HED reflects gain being applied by AGC. D14−D8 ADPGA_HED 1111111 R/W ADC Headset/Aux PGA Settings 0000000 => 0 dB 0000001 => 0.5 dB 0000010 => 1.0 dB ……… 1110110 => 59.0 dB .......... 1111111 => 59.5 dB Note: If AGC is enabled and Headset/Aux Input is selected then ADMUT_HED+ADPGA_HED reflects gain being applied by AGC. If AGC is on, the decoding for read values is as follows 01110111 => +59.5 dB 01110110 => +59.0 dB ……… 00000000 => 0 dB ………. 11101001 => −11.5 dB 11101000 => −12 dB D7−D5 AGCTG_HED 000 R/W AGC Target Gain for Headset/Aux Input. These three bits set the AGC’s targeted ADC output level. 000 => −5.5 dB 001 => −8.0 dB 010 => −10 dB 011 => −12 dB 100 => −14 dB 101 => −17 dB 110 => −20 dB 111 => −24 dB D4−D1 AGCTC_HED 0000 R/W AGC Time Constant for Headset/Aux Input. These four bits set the AGC attack and decay time constants. Time constants remain same irrespective of any sampling frequency FUNCTION Attack time (ms) 0000 8 0001 11 0010 16 0011 20 0100 8 0101 11 0110 16 0111 20 1000 8 1001 11 1010 16 1011 20 1100 8 1101 11 1110 16 1111 20 D0 AGCEN_HED 0 R/W Decay time (ms) 100 100 100 100 200 200 200 200 400 400 400 400 500 500 500 500 AGC Enable for Headset/Aux Input 0 => AGC is off for Headset/Aux Input (ADC Headset/Aux PGA is controlled by ADMUT_HED+ADPGA_HED) 1 => AGC is on for Headset/Aux Input (ADC Headset/Aux PGA is controlled by AGC) 51 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 02H: CODEC DAC Gain Control BIT NAME RESET VALUE READ/ WRITE D15 DALMU 1 R/W DAC Left Channel Mute 1 => DAC Left Channel Muted 0 => DAC Left Channel not muted D14−D8 DALVL 1111111 R/W DAC Left Channel Volume Control 0000000 => DAC left channel volume = 0 dB 0000001 => DAC left channel volume = −0.5 dB ….. 1111110 => DAC left channel volume = −63.0 dB 1111111 => DAC left channel volume = −63.5 dB D7 DARMU 1 R/W DAC Right Channel Mute 1 => DAC Right Channel Muted 0 => DAC Right Channel not muted D6−D0 DARVL 1111111 R/W DAC Right Channel Volume Control 0000000 => DAC right channel volume = 0 dB 0000001 => DAC right channel volume = −0.5 dB ….. 1111110 => DAC right channel volume = −63.0 dB 1111111 => DAC right channel volume = −63.5 dB FUNCTION REGISTER 03H: Mixer PGA Control BIT NAME RESET VALUE READ/ WRITE D15 ASTMU 1 R/W Analog Sidetone Mute Control 1 => Analog sidetone mute 0 => Analog sidetone not muted D14−D8 ASTG 1000101 R/W Analog Sidetone Gain Setting 0000000 => Analog sidetone = −34.5 dB 0000001 => Analog sidetone = −34 dB 0000010 => Analog sidetone = −33.5 dB ... 1000101 => Analog sidetone = 0 dB 1000110 => Analog sidetone = 0.5 dB ... 1011100 => Analog sidetone = 11.5 dB 1011101 => Analog sidetone = 12 dB 1011110 => Analog sidetone = 12 dB 1011111 => Analog sidetone = 12 dB 11xxxxx => Analog sidetone = 12 dB D7−D5 MICSEL 000 R/W Selection for Mic Input and Aux Input for ADC/Cell phone−output/Analog side−tone. 000 => Single-ended input MICIN_HED selected 001 => Single-ended input MICIN_HND selected 010 => Single-ended input AUX1 selected 011 => Single-ended input AUX2 selected 100 => Differential input MICIN_HED and AUX1 connected to ADC. 101 => Differential input MICIN_HED and AUX2 connected to ADC. 110 => Differential input MICIN_HND and AUX1 connected to ADC. 111 => Differential input MICIN_HND and AUX2 connected to ADC. Note: When D7=1 (differential input selected), analog side−tone path is not valid D4 MICADC 0 R/W Selection of ADC input 0 => Nothing connected 1 => Input selected by MICSEL connected to ADC. D3 CPADC 0 R/W Connects Cell phone input to ADC 0 => Cell phone input not connected to ADC. 1 => Cell phone input connected to ADC. D2−D1 Reserved 0’s R Reserved D0 ASTGF 0 R Analog Sidetone PGA Flag (Read Only) 0 => Gain Applied ≠ PGA Register setting 1 => Gain Applied = PGA register setting. Note: This flag indicates when the soft−stepping for analog sidetone is completed. 52 FUNCTION www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 04H: Audio Control 2 BIT NAME RESET VALUE READ/ WRITE D15 KCLEN 0 R/W Keyclick Enable 0 => Keyclick Disabled 1 => Keyclick Enabled Note: This bit is automatically cleared after giving out the keyclick signal length equal to the programmed value. D14−D12 KCLAC 100 R/W Keyclick Amplitude Control 000 => Lowest Amplitude …. 100 => Medium Amplitude …. 111 => Highest Amplitude D11 APGASS 0 R/W Headset/Aux or Handset PGA Soft−stepping control 0 => 0.5 dB change every WCLK or ADWS 1 => 0.5 dB change every 2 WCLK or 2 ADWS FUNCTION When AGC is enabled for Headset/Aux or Handset, this bit is read only and acts as Noise Threshold Flag. The read value indicates the following 0 => signal power greater than noise threshold 1 => signal power is less than noise threshold D10−D8 KCLFRQ 100 R/W Keyclick Frequency 000 => 62.5 Hz 001 => 125 Hz 010 => 250 Hz 011 => 500 Hz 100 => 1 kHz 101 => 2 kHz 110 => 4 kHz 111 => 8 kHz D7−D4 KCLLN 0001 R/W Keyclick Length 0000 => 2 periods key click 0001 => 4 periods key click 0010 => 6 periods key click 0011 => 8 periods key click 0100 => 10 periods key click 0101 => 12 periods key click 0110 => 14 periods key click 0111 => 16 periods key click 1000 => 18 periods key click 1001 => 20 periods key click 1010 => 22 periods key click 1011 => 24 periods key click 1100 => 26 periods key click 1101 => 28 periods key click 1110 => 30 periods key click 1111 => 32 periods key click D3 DLGAF 0 R DAC Left Channel PGA Flag 0 => Gain applied ≠ PGA register setting 1 => Gain applied = PGA register setting. Note: This flag indicates when the soft−stepping for DAC left channel is completed D2 DRGAF 0 R DAC Right Channel PGA Flag 0 => Gain applied ≠ PGA register setting 1 => Gain applied = PGA register setting. Note: This flag indicates when the soft−stepping for DAC right channel is completed 53 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 BIT NAME RESET VALUE READ/ WRITE D1 DASTC 0 R/W D0 ADGAF 0 R FUNCTION DAC Channel PGA Soft−stepping control 0 => 0.5 dB change every WCLK 1 => 0.5 dB change every 2 WCLK Headset/Aux or Handset PGA Flag 1 => Gain applied = PGA register setting. 0 => Gain applied ≠ PGA Register setting Note: This flag indicates when the soft−stepping for PGA is completed. When AGC is enabled for Headset/Aux or Handset, this bit is read−only and acts as Saturation Flag. The read value of this bit indicates the following 0 => AGC is not saturated 1 => AGC is saturated (PGA has reached –12 dB or max PGA applicable). REGISTER 05H: CODEC Power Control BIT NAME RESET VALUE READ/WRITE D15 MBIAS_HND 1 R/W MICBIAS_HND Power−down Control 0 => MICBIAS_HND is powered up. 1 => MICBIAS_HND is powered down. D14 MBIAS_HED 1 R/W MICBIAS_HED Power−down Control 0 => MICBIAS_HED is powered up. 1 => MICBIAS_HED is powered down. D13 ASTPWD 1 R/W Analog Sidetone Power−down Control 0 => Analog sidetone powered up 1 => Analog sidetone powered down D12 SP1PWDN 1 R/W SPK1(Single−Ended)/OUT32N(Differential) Power−down Control 0 => SPK1/OUT32N is powered up 1 => SPK1/OUT32N is powered down D11 SP2PWDN 1 R/W SPK2 Power−down Control 0 => SPK2 is powered up 1 => SPK2 is powered down D10 DAPWDN 1 R/W DAC Power−down Control 0 => DAC powered up 1 => DAC powered down D9 ADPWDN 1 R/W ADC Power−down Control 0 => ADC powered up 1 => ADC powered down D8 VGPWDN 1 R/W Driver Virtual Ground Power−down Control 0 => VGND is powered up 1 => VGND is powered down D7 COPWDN 1 R/W CP_OUT Power−down Control 0 => CP_OUT is powered up 1 => CP_OUT is powered down D6 LSPWDN 1 R/W Loudspeaker (8−Ω Driver) Power−down Control 0 => Loudspeaker (8−Ω driver) is powered up 1 => Loudspeaker (8−Ω driver) is powered down D5 ADPWDF 1 R ADC Power Down Flag 0 => ADC power down is not complete 1 => ADC power down is complete D4 LDAPWDF 1 R DAC Left Power Down Flag 0 => DAC left power down is not complete 1 => DAC left power down is complete D3 RDAPWDF 1 R DAC Right Power Down Flag 0 => DAC right power down is not complete 1 => DAC right power down is complete D2 ASTPWF 1 R Analog Sidetone Power Down Flag 0 => Analog sidetone power down is not complete 1 => Analog sidetone power down is complete 54 FUNCTION www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 BIT NAME RESET VALUE READ/WRITE D1 EFFCTL 0 R/W Digital Audio Effects Filter 0 => Disable digital audio effects filter 1 => Enable digital audio effects filter FUNCTION D0 DEEMPF 0 R/W De−emphasis Filter Enable 0 => Disable de−emphasis filter 1 => Enable de−emphasis filter NOTE: D15−D6 are all 1’s, then full codec section is powered down. REGISTER 06H: Audio Control 3 BIT NAME RESET VALUE READ/ WRITE D15−D14 DMSVOL 00 R/W DAC Channel Master Volume Control 00 => Left channel and right channel have independent volume controls 01 => Left channel volume control is the programmed value of the right channel volume control. 10 => Right channel volume control is the programmed value of the left channel volume control. 11 => same as 00 D13 REFFS 0 R/W Reference Sampling Rate Note: This setting controls the coefficients in the de−emphasis filter, the time−constants in AGC, and internal divider values that generate the clock for the auxiliary measurement ADC. If an Fsref above 48 kHz is being used, then it is recommended to set this to the 48−kHz setting, otherwise either setting can be used. 0 => Fsref = 48.0 kHz 1 => Fsref = 44.1 kHz D12 DAXFM 0 R/W Master Transfer Mode 0 => Continuous data transfer mode 1 => 256−s data transfer mode D11 SLVMS 0 R/W CODEC Master Slave Selection 0 => The AIC28 is slave codec 1 => The AIC28 is master codec D10−D9 FUNCTION 0’s R Reserved D8 ADCOVF 0 R ADC Channel Overflow Flag 0 => ADC channel data is within saturation limits 1 => ADC channel data has exceeded saturation limits. Note: This flag gets reset after register read. D7 DALOVF 0 R DAC Left Channel Overflow Flag 0 => DAC left channel data is within saturation limits 1 => DAC left channel data has exceeded saturation limits Note: This flag gets reset after register read. D6 DAROVF 0 R DAC Right Channel Overflow Flag 0 => DAC right channel data is within saturation limits 1 => DAC right channel data has exceeded saturation limits Note: This flag gets reset after register read. D5−D4 00 R/W Reserved. D3 CLPST 0 R/W MIC AGC Clip Stepping Disable 0 => Disabled 1 => Enabled Note: Valid only when AGC is selected for the Headset/Aux or Handset input. D2−D0 REVID XXX R AIC28 Device Revision ID REGISTER 07H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_N0 27619 R/W FUNCTION Left channel bass-boost coefficient N0. REGISTER 08H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_N1 −27034 R/W FUNCTION Left channel bass-boost coefficient N1. 55 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 09H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_N2 26461 R/W FUNCTION Left channel bass-boost coefficient N2. REGISTER 0AH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_N3 27619 R/W FUNCTION Left channel bass-boost coefficient N3. REGISTER 0BH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_N4 −27034 R/W FUNCTION Left channel bass-boost coefficient N4. REGISTER 0CH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_N5 26461 R/W FUNCTION Left channel bass-boost coefficient N5. REGISTER 0DH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_D1 32131 R/W FUNCTION Left channel bass-boost coefficient D1. REGISTER 0EH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_D2 −31506 R/W FUNCTION Left channel bass-boost coefficient D2. REGISTER 0FH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_D4 32131 R/W FUNCTION Left channel bass-boost coefficient D4. REGISTER 10H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 L_D5 −31506 R/W FUNCTION Left channel bass-boost coefficient D5. REGISTER 11H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_N0 27619 R/W FUNCTION Right channel bass-boost coefficient N0. REGISTER 12H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_N1 −27034 R/W FUNCTION Right channel bass-boost coefficient N1. REGISTER 13H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_N2 26461 R/W FUNCTION Right channel bass-boost coefficient N2. REGISTER 14H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_N3 27619 R/W 56 FUNCTION Right channel bass-boost coefficient N3. www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 15H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_N4 −27034 R/W FUNCTION Right channel bass-boost coefficient N4. REGISTER 16H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_N5 26461 R/W FUNCTION Right channel bass-boost coefficient N5. REGISTER 17H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_D1 32131 R/W FUNCTION Right channel bass-boost coefficient D1. REGISTER 18H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_D2 −31506 R/W FUNCTION Right channel bass-boost coefficient D2. REGISTER 19H: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_D4 32131 R/W FUNCTION Right channel bass-boost coefficient D4. REGISTER 1AH: Digital Audio Effects Filter Coefficients BIT NAME RESET VALUE (IN DECIMAL) READ/ WRITE D15−D0 R_D5 −31506 R/W FUNCTION Right channel bass-boost coefficient D5. REGISTER 1BH: PLL Programmability BIT NAME RESET VALUE READ/WRITE FUNCTION D15 PLLSEL 0 R/W PLL Enable 0 => Disable PLL. 1 => Enable PLL. D14−D11 QVAL 0010 R/W Q value: Valid when PLL is disabled 0000 => 16, 0001 => 17, 0010 => 2, 0011 => 3, ……. 1100 => 12, 1101 => 13, 1110 => 14, 1111 => 15, D10−D8 PVAL 000 R/W P value: Valid when PLL is enabled 000 => 8, 001 => 1, 010 => 2, 011 => 3, 100 => 4, 101 => 5, 110 => 6, 111 => 7 57 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 D7−D2 J_VAL D1−D0 000001 R/W 00 R J value: Valid when PLL is enabled 000000 => Not valid, 000001 => 1, 000010 => 2, 000011 => 3, …….. 111100 => 60, 111101 => 61, 111110 => 62, 111111 => 63 Reserved (Write only 00) REGISTER ICH: PLL Programmability BIT NAME RESET VALUE READ/WRITE D15−D2 D_VAL 0 (decimal) R/W D1−D0 Reserved 0 R FUNCTION D value: Valid when PLL is enabled D value is valid from 0000 to 9999 in decimal. Greater than 9999 is treated as 9999. Reserved (Write only 00) REGISTER IDH: Audio Control 4 BIT NAME RESET VALUE READ/WRITE D15 ADSTPD 0 R/W Headset/Aux or Handset PGA Soft−stepping Control 0 => Enable soft−stepping 1 => Disable soft−stepping D14 DASTPD 0 R/W DAC PGA Soft−stepping Control 0 => Enable soft−stepping 1 => Disable soft−stepping D13 ASSTPD 0 R/W Analog Sidetone PGA Soft−stepping Control 0 => Enable soft−stepping 1 => Disable soft−stepping Note: When soft−stepping is enabled gain is changed 0.5 dB per Fsref. D12 CISTPD 0 R/W Cell−phone PGA Soft−stepping Control 0 => Enable soft−stepping 1 => Disable soft−stepping Note: When soft−stepping is enabled gain is changed 0.5 dB per Fsref. D11 BISTPD 0 R/W Buzzer PGA Soft−stepping Control 0 => Enable soft−stepping 1 => Disable soft−stepping Note: When soft−stepping is enabled gain is changed 3 dB per Fsref. D10−D9 AGCHYS 00 R/W MIC AGC Hysteresis selection 00 => 1 dB 01 => 2 dB 10 => 4 dB 11 => No Hysteresis Note: Valid only when AGC is selected for Headset/Aux or Handset input D8−D7 MB_HED 00 R/W Micbias for Headset 00 => MICBIAS_HED = 3.3 V 01 => MICBIAS_HED = 2.5 V 10 => MICBIAS_HED = 2.0 V 11 => MICBIAS_HED = 2.0 V D6 MB_HND 0 R/W Micbias for Handset 0 => MICBIAS_HND = 2.5 V 1 => MICBIAS_HND = 2.0 V 0’s R Reserved (Write only 0000) 0 R Driver Short Circuit Protection Flag. 0 => No short circuit happened. 1 => Short circuit detected on headphone outputs. X R Reserved (Write only 0) D5−D2 D1 D0 58 SCPFL FUNCTION www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 1EH: Gain Control for Handset Input BIT NAME RESET VALUE READ/WRITE D15 ADMUT_HND 1 R/W Handset Input Mute 1 => Handset Input Mute 0 => Handset Input not muted Note: If AGC is enabled and handset Input is selected then ADMUT_HND+ADPGA_HND will reflect gain being applied by AGC. FUNCTION D14−D8 ADPGA_HND 1111111 R/W D7−D5 AGCTG_HND 000 R/W ADC Handset PGA Settings 0000000 => 0 dB 0000001 => 0.5 dB 0000010 => 1.0 dB .... 1110110 => 59.0 dB ............. 1111111 => 59.5 dB Note: If AGC is enabled and handset Input is selected then ADMUT_HND+ADPGA_HND will reflect gain being applied by AGC. If AGC is on, the decoding for read values is as follows 01110111 => +59.5 dB 01110110 => +59.0 dB ……… 00000000 => 0 dB ………. 11101000 => −12 dB AGC Target Gain for Handset Input. These three bits set the AGC’s targeted ADC output level. 000 => −5.5 dB 001 => −8.0 dB 010 => −10 dB 011 => −12 dB 100 => −14 dB 101 => −17 dB 110 => −20 dB 111 => −24 dB D4−D1 AGCTC_HND 0000 R/W AGC Time Constant for Handset Input. These four bits set the AGC attack and decay time constants. Time constants remain the same irrespective of any sampling frequency. Attack time Decay time (ms) (ms) 0000 8 100 0001 11 100 0010 16 100 0011 20 100 0100 8 200 0101 11 200 0110 16 200 0111 20 200 1000 8 400 1001 11 400 1010 16 400 1011 20 400 1100 8 500 1101 11 500 1110 16 500 1111 20 500 D0 AGCEN_HND 0 R/W AGC Enable for Handset Input 0 => AGC is off for Handset Input (ADC PGA is controlled by ADMUT_HND+ADPGA_HND) 1 => AGC is on for Handset Input (ADC PGA is controlled by AGC) 59 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 1FH: Gain Control for Cell Phone Input and Buzzer Input BIT NAME RESET VALUE READ/WRITE D15 MUT_CP 1 R/W Cell phone Input PGA Power−down 1 => Power−down cell-phone input PGA 0 => Power−up cell phone input PGA FUNCTION D14−D8 CPGA 1000101 R/W Cell−phone Input PGA Settings. 0000000 => −34.5 dB 0000001 => −34 dB 0000010 => −33.5 dB ... 1000101 => 0 dB 1000110 => 0.5 dB ... 1011100 => 11.5 dB 1011101 => 12 dB 1011110 => 12 dB 1011111 => 12 dB 11xxxxx => 12 dB Note: These bits are read−only when AGC is enabled for CP_IN (cell-phone input) and reflect the gain applied by the AGC. D7 CPGF 0 R Cell phone Input PGA Flag (Read Only) 0 => Gain applied ≠ PGA register setting 1 => Gain applied = PGA register setting. Note: This flag indicates when the soft−stepping for cell-phone input is completed. When AGC is enabled for Cell−phone input, this bit is read−only and acts as Saturation Flag. The read value of this bit indicates the following 0 => AGC is not saturated 1 => AGC is saturated (PGA has reached –34.5 dB or max PGA applicable). D6 MUT_BU 1 R/W Buzzer Input PGA Power−down 1 => Power−down buzzer input PGA 0 => Power−up buzzer input PGA D5−D2 BPGA 1111 R/W Buzzer Input PGA settings. 1111 => 0 dB 1110 => −3 dB 1101 => −6 dB 1100 => −9 dB 1011 => −12 dB 1010 => −15 dB 1001 => −18 dB 1000 => −21 dB 0111 => −24 dB 0110 => −27 dB 0101 => −30 dB 0100 => −33 dB 0011 => −36 dB 0010 => −39 dB 0001 => −42 dB 0000 => −45 dB D1 BUGF 0 R Buzzer PGA Flag (Read Only) 0 => Gain Applied ≠ PGA Register setting 1 => Gain Applied = PGA register setting. Note: This flag indicates when the soft−stepping for buzzer input is completed. 0 R Reserved (Write only 0) D0 60 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 20H: Audio Control 5 DIFFIN RESET VALUE 0 READ/ WRITE R/W D14−D13 DAC2SPK1 00 R/W DAC Channel Routing to SPK1 (Single-ended)/ SPK1−OUT32N (Differential) 00 => No routing from DAC to SPK1/ SPK1−OUT32N 01 => DAC left routed to SPK1/SPK1−OUT32N 10 => DAC right routed to SPK1/SPK1−OUT32N 11 => DAC (left + right)/2 routed to SPK1/SPK1−OUT32N D12 AST2SPK1 0 R/W Analog Sidetone Routing to SPK1 (Single-ended)/SPK1−OUT32N (Differential) 0 => No routing from analog sidetone to SPK1/SPK1−OUT32N 1 => Analog sidetone routed to SPK1/SPK1−OUT32N D11 BUZ2SPK1 0 R/W Buzzer PGA Routing to SPK1 (Single-ended)/ SPK1−OUT32N (Differential) 0 => No routing from buzzer PGA to SPK1/SPK1−OUT32N 1 => Buzzer PGA routed to SPK1/ SPK1−OUT32N D10 KCL2SPK1 0 R/W Keyclick Routing to SPK1 (Single-ended)/SPK1−OUT32N (Differential) 0 => No routing from keyclick to SPK1/SPK1−OUT32N 1 => Keyclick routed to SPK1/SPK1−OUT32N D9 CPI2SPK1 0 R/W Cell−phone Input Routing to SPK1 (Single-ended)/SPK1−OUT32N (Differential) 0 => No routing from cell-phone input to SPK1/SPK1−OUT32N 1 => Cell phone input routed to SPK1/SPK1−OUT32N D8−D7 DAC2SPK2 00 R/W DAC Channel Routing to SPK2 (Valid for Only Single-ended) 00 => No routing from DAC to SPK2 01 => DAC left routed to SPK2 10 => DAC right routed to SPK2 11 => DAC (left + right)/2 routed to SPK2 D6 AST2SPK2 0 R/W Analog Sidetone Routing to SPK2 (Valid for Only Single-ended) 0 => No routing from analog sidetone to SPK2 1 => Analog sidetone routed to SPK2 D5 BUZ2SPK2 0 R/W Buzzer PGA Routing to SPK2 (Valid for Only Single-ended) 0 => No routing from buzzer PGA to SPK2 1 => Buzzer PGA routed to SPK2 D4 KCL2SPK2 0 R/W Keyclick Routing to SPK2 (Valid for Only Single-ended) 0 => No routing from keyclick to SPK2 1 => Keyclick routed to SPK2 D3 CPI2SPK2 0 R/W Cell−phone Input Routing to SPK2 (Valid for Only Single-ended) 0 => No routing from cell-phone input to SPK2 1 => Cell−phone input routed to SPK2 D2 MUTSPK1 1 R/W Mute Control for SPK1 (Single-ended)/SPK1−OUT32N (Differential) 0 => SPK1/SPK1−OUT32N is not muted. 1 => SPK1/SPK1−OUT32N is muted. D1 MUTSPK2 1 R/W Mute Control for SPK2 (Valid for Only Single-ended) 0 => SPK2 is not muted. 1 => SPK2 is muted. D0 HDSCPTC 0 W BIT NAME D15 FUNCTION Single-ended or Differential Output Selection. 0 => Single-ended output (headset/lineout) selected for SPK1 and SPK2 drivers 1 => Differential output (handset) selected for SPK1 and OUT32N drivers Note: When bit D15=1, both SPK1 and OUT32N drivers should be power−up. Otherwise the AIC28 automatically power−down both SPK1 and OUT32N drivers. Headphone Short−circuit Protection Control 0 => Enable short−circuit protection 1 => Disable short−circuit protection 61 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 21H: Audio Control 6 BIT NAME RESET VALUE READ/ WRITE D15 SPL2LSK 0 R/W Routing Selected for SPK1 Goes to OUT8P−OUT8N (Loudspeaker) Also. 0 => None of the routing selected for SPK1 goes to OUT8P−OUT8N. 1 => Routing selected for SPK1 using D14−D9 of control register 20H/page 2 goes to OUT8P−OUT8N. Note: This programming is valid only if SPK1/OUT32N and SPK2 are powered down. D14 AST2LSK 0 R/W Analog Sidetone Routing to OUT8P−OUT8N (Loudspeaker) 0 => No routing from analog sidetone to OUT8P−OUT8N 1 => Analog sidetone routed to OUT8P−OUT8N D13 BUZ2LSK 0 R/W Buzzer PGA Routing to OUT8P−OUT8N (Loudspeaker) 0 => No routing from buzzer PGA to OUT8P−OUT8N 1 => Buzzer PGA routed to OUT8P−OUT8N D12 KCL2LSK 0 R/W Keyclick Routing to OUT8P−OUT8N (Loudspeaker) 0 => No routing from keyclick to OUT8P−OUT8N 1 => Keyclick routed to OUT8P−OUT8N D11 CPI2LSK 0 R/W Cell−phone Input Routing to OUT8P−OUT8N (Loudspeaker) 0 => No routing from cell-phone input to OUT8P−OUT8N 1 => Cell−phone input routed to OUT8P−OUT8N D10 MIC2CPO 0 R/W MICSEL (Programmed Using Control Register 04H/Page 2) Routed to Cell-phone Output. 0 => No routing from MICSEL to CP_OUT. 1 => MICSEL routed to CP_OUT. D9 SPL2CPO 0 R/W Routing Selected for SPK1 (Other Than Cell−phone Input) Goes to Cell-phone Output Also. 0 => None of the routing selected for SPK1 goes to cell-phone output. 1 => Routing selected for SPK1 using D14−D10 of control register 20H/page 2 goes to CP_OUT. Note: This programming is valid even if SPK1/OUT32N and SPK2 are powered down. D8 SPR2CPO 0 R/W Routing Selected for SPK2 Goes to Cell−phone Output Also (Valid for Only Single-ended). 0 => None of the routing selected for SPK2 goes to cell-phone output. 1 => Routing selected for SPK2 using D8−D3 of control register 20H/page2 goes to CP_OUT. Note: 1. This programming is valid even if SPK2 is power-down. 2. This programming is not valid when routing selected for SPK1 is routed to loudspeaker D7 MUTLSPK 1 R/W Mute Control for OUT8P−OUT8N Loudspeaker 0 => OUT8P−OUT8N is not muted. 1 => OUT8P−OUT8N is muted. D6 MUTSPK2 1 R/W Mute Control for Cell−phone Output 0 => CPOUT is not muted. 1 => CPOUT is muted. D5 LDSCPTC 1 R/W Loudspeaker Short−circuit Protection Control 0 => Enable short−circuit protection for loudspeaker 1 => Disable short−circuit protection for loudspeaker D4 VGNDSCPTC 0 R/W VGND Short−circuit Protection Control 0 => Enable short−circuit protection for VGND driver 1 => Disable short−circuit protection for VGND driver D3 CAPINTF 0 R/W Cap/Cap−less Interface Select for Headset. 0 => Select cap−less interface. 1 => Select cap interface. 0’s R D2−D0 62 FUNCTION Reserved (Write only 000) www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 22H: Audio Control 7 BIT NAME RESET VALUE READ/ WRITE D15 DETECT 0 R/W D14−D13 HESTYPE 00 R Type of Headset Detected. 00 => No headset detected. 01 => Stereo headset detected. 10 => Cellular headset detected 11 => Stereo+cellular headset detected Note: These two bits are valid only if the headset detection is enabled. D12 HDDETFL 0 R Headset Detection Flag. 0 => Headset is not detected 1 => Headset is detected. D11 BDETFL 0 R Button Press Detection Flag. 0 => Button press is not detected 1 => Button press is detected. D10−D9 HDDEBNPG 01 R/W 0 R BDEBNPG 00 R/W D8 D7−D6 D5 FUNCTION Headset Detection 0 => Disable headset detection 1 => Enable headset detection De−bouncing Programmability for Glitch Rejection During Headset Detection. 00 => 16 ms duration (with 2 ms clock resolution) 01 => 32 ms duration (with 4 ms clock resolution) 10 => 64 ms duration (with 8 ms clock resolution) 11 => 128 ms duration (with 16 ms clock resolution) Reserved (Write only 0) De−bouncing Programmability for Glitch Rejection During Button Press Detection. 00 => No glitch rejection. 01 => 8 ms duration (with 1 ms clock resolution) 10 => 16 ms duration (with 2 ms clock resolution) 11 => 32 ms duration (with 4 ms clock resolution) 0 R D4 DGPIO2 0 R/W Reserved (Write only 0) Enable GPIO2 for Headset Detection Interrupt 0 => Disable GPIO2 for headset detection interrupt 1 => Enable GPIO2 for headset detection interrupt Note: This programmability is valid only if D15 and D13 of control register 23H/page 2 are set to 0 D3 DGPIO1 0 R/W Enable GPIO1 for Headset Detection Interrupt 0 => Disable GPIO1 for Detection interrupt 1 => Enable GPIO1 for Detection interrupt Note: This programmability is valid only if D11 and D9 of control register 23H/page 2 are set to 0 D2 CLKGPIO2 0 R/W Enable GPIO2 for CLKOUT 0 => Disable GPIO2 for CLKOUT mode. 1 => Enable GPIO2 for CLKOUT mode. In CLKOUT mode the frequency of output signal is equal to the 256xDAC_FS if DAC_FS is faster than ADC_FS otherwise equal to the 256xADC_FS. Note: This programmability is valid only if PLL is enabled, D15 and D13 of register 23H/page 2 are set to 0 and GPIO2 is not enabled for detection interrupt. D1−D0 ADWSF 00 R/W ADWS Selection 0X => GPIO1 pin output is tri−stated. 10 => GPIO1 pin acts as button press detect interrupt. 11 => GPIO1 pin acts as ADC word−select (ADWS). Note: 1. This programmability is valid only if D11 and D9 of control register 23H/page 2 are set to 0. 2. These bits should be programmed ‘11’ only if different ADC and DAC sample rates are desired. In this mode WCLK acts as DAWS i.e. DAC sample rate and GPIO1 acts as ADWS i.e. ADC sample rate. 63 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 23H: GPIO Control BIT NAME RESET VALUE READ/ WRITE D15 GPO2EN 0 R/W GPIO2 Enable for General Purpose Output Port 0 => GPIO2 is not programmed as general purpose output port 1 => GPIO2 programmed as general purpose output port D14 GPO2SG 0 R/W GPIO2 Output Signal Programmability 0 => GPIO2 goes to low if GPIO2 enable for general purpose output port 1 => GPIO2 goes to high if GPIO2 enable for general purpose output port D13 GPI2EN 0 R/W GPIO2 Enable for General Purpose Input Port 0 => GPIO2 is not programmed as general purpose input port 1 => GPIO2 programmed as general purpose input port D12 GPI2SGF 0 R D11 GPO1EN 0 R/W GPIO1 Enable for General Purpose Output Port 0 => GPIO1 is not programmed as general purpose output port 1 => GPIO1 programmed as general purpose output port D10 GPO1SG 0 R/W GPIO1 Output Signal Programmability 0 => GPIO1 goes to low if GPIO1 enable for general purpose output port 1 => GPIO1 goes to high if GPIO1 enable for general purpose output port D9 GPI1EN 0 R/W GPIO1 Enable for General Purpose Input Port 0 => GPIO1 is not programmed as general purpose input port 1 => GPIO1 programmed as general purpose input port D8 GPI1SGF 0 R GPIO1 Input Signal Flag 0 => GPIO1 input is low. 1 => GPIO1 input is high. Note: Valid only if GPIO1 is enable for general purpose input port 0 R Reserved (Write only 00000000) D7−D0 FUNCTION GPIO2 Input Signal Flag 0 => GPIO2 input is low. 1 => GPIO2 input is high. Note: Valid only if GPIO2 is enable for general purpose input port REGISTER 24H: AGC for Cell-Phone Input Control BIT NAME D15 RESET VALUE READ/ WRITE FUNCTION 0 R Reserved (Write only 0) D14 AGCNF_CELL 0 R Noise Threshold Flag. The read values indicate the following 0 => Signal power greater than noise threshold 1 => Signal power is less than noise threshold Note: Valid only if AGC is selected for the Cell−phone input (CP_IN). D13−D11 AGCNL 000 R/W AGC Noise Threshold. These settings apply to both Headset/Aux/Handset and Cell−phone input. 000 => −30 dB 001 => −30 dB 010 => −40 dB 011 => −50 dB 100 => −60 dB 101 => −70 dB (not valid for Cell−phone AGC) 110 => −80 dB (not valid for Cell−phone AGC) 111 => −90 dB (not valid for Cell−phone AGC) D10−D9 AGCHYS_CELL 00 R/W AGC Hysteresis Selection for Cell−phone Input 00 => 1 dB 01 => 2 dB 10 => 4 dB 11 => No Hysteresis D8 CLPST_CELL 0 R/W AGC Clip Stepping Disable for Cell−phone Input 0 => Disable clip stepping for cell-phone input 1 => Enable clip stepping for cell-phone input 64 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 BIT NAME RESET VALUE READ/ WRITE D7−D5 AGCTG_CELL 000 R/W AGC Target Gain for Cell−phone Input. These three bits set the AGC’s targeted ADC output level. 000 => −5.5 dB 001 => −8.0 dB 010 => −10 dB 011 => −12 dB 100 => −14 dB 101 => −17 dB 110 => −20 dB 111 => −24 dB D4−D1 AGCTC_CELL 0000 R/W AGC Time Constant for Cell Input. These four bits set the AGC attack and decay time constants. Time constants remain the same irrespective of any sampling frequency Attack time Decay time (ms) (ms) 0000 8 10 0001 11 100 0010 16 100 0011 20 100 0100 8 200 0101 11 200 0110 16 200 0111 20 200 1000 8 400 1001 11 400 1010 16 400 1011 20 400 1100 8 500 1101 11 500 1110 16 500 1111 20 500 D0 AGCEN_CELL 0 R/W AGC Enable for Cell−phone Input 0 => AGC is off for Cell−phone input 1 => AGC is on for Cell−phone input (Cell PGA is controlled by AGC FUNCTION REGISTER 25H: Driver Power-Down Status Note: All values reflected in control register 25H/page2 are valid only if short circuit is not detected (bit D1 of control register 1DH/page2 is set to 0) BIT NAME RESET VALUE READ/ WRITE D15 SPK1FL 1 R SPK1 Driver Power-down Status 0 => SPK1 driver not powered down. 1 => SPK1 driver powered down. D14 SPK2FL 1 R SPK2 Driver Power-down Status 0 => SPK2 driver not powered down. 1 => SPK2 driver powered down. D13 HNDFL 1 R OUT32N (Handset) Driver Power-down Status 0 => OUT32N driver not powered down. 1 => OUT32N driver powered down. D12 VGNDFL 1 R VGND Driver Power-down Status 0 => VGND driver not powered down. 1 => VGND driver powered down. D11 LSPKFL 1 R Loudspeaker Driver Power-down Status 0 => Loudspeaker driver not powered down. 1 => Loudspeaker driver powered down. D10 CELLFL 1 R Cell−phone Output (CP_OUT) Driver Power-down Status 0 => Cell-phone output driver not powered down. 1 => Cell-phone output driver powered down. FUNCTION 65 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 BIT NAME RESET VALUE D9−D6 READ/ WRITE FUNCTION 0000 R D5 PSEQ 0 R/W Disable Drivers (SPK1/SPK2/OUT32N/VGND) Pop Sequencing 0 => Enable drivers pop sequencing 1 => Disable drivers pop sequencing D4 PSTIME 0 R/W Drivers (SPK1/SPK2) Pop Sequencing Duration in Cap Mode 0 => 802 ms. 1 => 4006 ms. 0000 R D3−D0 Reserved (Write only 0000) Reserved (Write only 0000) REGISTER 26H: Mic AGC Control BIT NAME RESET VALUE READ/ WRITE D15−D9 MMPGA 1111111 R/W Max PGA Value Applicable for Headset/Aux or Handset AGC 0000000 => 0 dB 0000001 => 0.5 dB 0000010 => 1.0 dB .... 1110110 => 59.0 dB ............ 1111111 => 59.5 dB D8−D6 MDEBNS 000 R/W Debounce Time for Transition from Normal Mode to Silence Mode (Input Level is Below Noise Threshold Programmed by AGCNL). This is Valid for Headset/Aux or Handset AGC. 000 => 0 ms 001 => 0.5 ms 010 => 1.0 ms 011 => 2.0 ms 100 => 4.0 ms 101 => 8.0 ms 110 => 16.0 ms 111 => 32.0 ms D5−D3 MDEBSN 000 R/W De−bounce Time for Transition from Silence Mode to Normal Mode. This is Valid for Headset/Aux or Handset AGC. 000 => 0 ms 001 => 0.5 ms 010 => 1.0 ms 011 => 2.0 ms 100 => 4.0 ms 101 => 8.0 ms 110 => 16.0 ms 111 => 32.0 ms 000 R D2−D0 66 FUNCTION Reserved (Write only 000) www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 REGISTER 27H: Cell-Phone AGC Control BIT NAME RESET VALUE READ/ WRITE D15−D9 CMPGA 1111111 R/W D8−D6 CDEBNS 000 R De−bounce Time for Transition from Normal Mode to Silence Mode (Input Level is Below Noise Threshold Programmed by AGCNL). This is Valid for Cell−phone AGC. 000 => 0 ms 001 => 0.5 ms 010 => 1.0 ms 011 => 2.0 ms 100 => 4.0 ms 101 => 8.0 ms 110 => 16.0 ms 111 => 32.0 ms D5−D3 CDEBSN 000 R De−bounce Time for Transition from Silence Mode to Normal Mode. This is Valid for Cell−phone AGC. 000 => 0 ms 001 => 0.5 ms 010 => 1.0 ms 011 => 2.0 ms 100 => 4.0 ms 101 => 8.0 ms 110 => 16.0 ms 111 => 32.0 ms 000 R Reserved (Write only 000) D2−D0 FUNCTION Max. Cell‘−phone input PGA value applicable for Cell‘−phone AGC 0000000 => −34.5 dB 0000001 => −34 dB 0000010 => −33.5 dB ... 1000100 => −0.5 dB 1000101 => invalid 1000110 => invalid ... 1011100 => Invalid 1011101 => 12 dB 1011110 => 12 dB 1011111 => 12 dB 11xxxxx => 12 dB 67 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 AIC28 Buffer Data Registers (Page 3) The buffer data registers of the AIC28 hold data results from the SAR ADC conversions in buffer mode. Upon reset, bit D15 is set to 0, bit D14 is set to 1 and the remaining bits are don’t−care. These registers are read only. If buffer mode is enabled, then the results of all ADC conversions are placed in the buffer data register. The data format of the result word (R) of these registers is right-justified which is as follows: D15 MSB D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 LSB FUF EMF X ID R11 MSB R10 R9 R8 R7 R6 R5 R4 R3 R2 R1 R0 LSB BIT NAME RESET VALUE READ/ WRITE D15 FUF 0 R Buffer Full Flag This flag indicates that all the 64 locations of the buffer are having unread data. D14 EMF 1 R Buffer Empty Flag This flag indicates that there is no unread data available in FIFO. This is generated while reading the last converted data. X R Reserved X R Data Identification 0 => BAT or AUX2 data in R11−R0 1 => AUX1 or TEMP data in R11−R0 D13 D12 ID FUNCTION Order for Writing Data in Buffer When Multiple Inputs are Selected For Auto Scan Conversion: AUX1 (if selected), AUX2 (if selected), TEMP (if selected) For Port Scan Conversion: BAT, AUX1, AUX2 D11−D0 R11−R0 X’s R Converted Data LAYOUT The following layout suggestions should provide optimum performance from the AIC28. However, many portable applications have conflicting requirements concerning power, cost, size, and weight. In general, most portable devices have fairly clean power and grounds because most of the internal components are very low power. This situation would mean less bypassing for the converter’s power and less concern regarding grounding. Still, each situation is unique and the following suggestions should be reviewed carefully. For optimum performance, care should be taken with the physical layout of the AIC28 circuitry. The basic SAR architecture is sensitive to glitches or sudden changes on the power supply, reference, ground connections, and digital inputs that occur just prior to latching the output of the analog comparator. Therefore, during any single conversion for an n-bit SAR converter, there are n windows in which large external transient voltages can easily affect the conversion result. Such glitches might originate from switching power supplies, nearby digital logic, and high power devices. The degree of error in the digital output depends on the reference voltage, layout, and the exact timing of the external event. The error can change if the external event changes in time with respect to the timing of the critical n windows. With this in mind, power to the AIC28 should be clean and well bypassed. A 0.1 µF ceramic bypass capacitor should be placed as close to the device as possible. A 1 µF to 10 µF capacitor may also be needed if the impedance of the connection between the AIC28 supply pins and system power supply is high. A bypass capacitor on the VREF pin is generally not needed because the reference is buffered by an internal op amp, although it can be useful to reduce reference noise level. If an external reference voltage originates from an op amp, make sure that it can drive any bypass capacitor that is used without oscillation. The AIC28 architecture offers no inherent rejection of noise or voltage variation in regards to using an external reference input. This is of particular concern when the reference input is tied to the power supply. Any noise and ripple from the supply appears directly in the digital results. While high frequency noise can be filtered out, voltage variation due to line frequency (50 Hz or 60 Hz) can be difficult to remove. The ground pins should be connected to a clean ground point. In many cases, this is the analog ground. Avoid connections, which are too near the grounding point of a microcontroller or digital signal processor. If needed, run a ground trace directly from the converter to the power supply entry or battery connection point. The ideal layout includes an analog ground plane dedicated to the converter and associated analog circuitry. 68 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 CONVERSION TIME CALCULATIONS FOR THE AIC28 Auxiliary Measurement Operation The time needed to make temperature, auxiliary, or battery measurements is given by: t+ NJ ƪǒ N AVG N BITS ƫ Nj Ǔ 8 MHz ) n ) n ) 1 1 2 ƒ conv )1 t OSC ) 15 t OSC ) n3 t OSC where: n1 = 6 ; if ƒconv = 8 MHz 7 ; if ƒconv ≠ 8 MHz n2 = 24 ; if measurement is for TEMP1 case 12 ; if measurement is for other than TEMP1 case 400 ns; if measurement is for the external/internal resistance using AUX1/AUX2 n3 = 0 ; if external reference mode is selected 3 ; if tREF = 0 µs or reference is programmed for power up all the time. 1 + tREF /125 ns; if tREF ≠ 0 µs and reference needs to power down between conversions. tREF is the reference power up delay time. REG−00 of PAGE−01 Is Updated for BAT1 Scan Mode Waiting for Host to Write into REG−00 of PAGE−01 Reading BAT1−Data Register SS DEACTIVATED Wait for Reference Power-Up Delay in Case of Internal Ref Mode if Applicable Sample,Conversion & Waiting for Host to Averaging for Write into REG−00 BAT1 Input of PAGE−01 DAV (PAGE01H,REG01H [D15−D14 = 01]) The time needed for continuous autoscan mode is given by: t+N INP ǒNJ N ) n2 AVG t ƪǒ N OSC BITS )t Ǔ )1 DEL ƫ Nj 8 MHz ) n ) 12 ) 1 1 ƒ conv ) n3 ) t OSC ) n4 t t OSC )8 t OSC Ǔ OSC where: NINP = 1; if autoscan is selected for only one input AUX1, AUX2, TEMP1 or TEMP2 = 2; if autoscan is selected for two inputs AUX1−AUX2, AUX1−TEMP1, AUX1−TEMP2 etc = 3; if autoscan is selected for three inputs AUX1−AUX2−TEMP1 or AUX1−AUX2−TEMP2 n1 = 6 ; if fconv = 8 MHz 7 ; if fconv p 8 MHz n2 = 12 ; if one of the input selected is TEMP1 0 ; if measurement is for other than TEMP1 n3 = 0 ; if external reference mode is selected or tDEL = 0. 3 ; if tREF = 0 ms or reference is programmed for power up all the times. 1 + tREF/125 ns ; if tREF p 0us and reference needs to power down between conversions. tREF is the reference power up delay time. 69 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 n4 = 0 ; if tDEL = 0. = 7 ; if tDEL p 0 tDEL = Programmable delay in between conversion = 0 ; if programmable delay mode is disabled (1) The above equation is valid only from second conversion onwards. (2) t DEL delay is generated by using internal oscillator clock whose typical frequency is 1 MHz in internal clock mode, or MCLK/CLKDIV (as programmed in control register 14H/page 1) in external clock mode. REG−00 of PAGE−01 Is Updated for Continous AUX SCAN Mode Reading AUX−Data Register SS DEACTIVATED Waiting for Host to Write into REG−00 of PAGE−01 Wait for Reference Power-Up Delay in Case of Internal Ref Mode if Applicable Reading AUX−Data Register Sample,Conversion & Sample,Conversion & Averaging for Averaging for AUX input AUX input Sample,Conversion & Averaging for AUX input DAV (PAGE01H,REG01H [D15−D14 = 01]) Port Scan Operation The time needed to complete one set of port scan conversions is given by: t coordinate +3 NJ ƪǒ N AVG N BITS Ǔ )1 ƫ Nj 8 MHz ) n ) 12 ) 1 1 ƒ conv t OSC ) 31 t OSC ) n2 where: n1 = 6 ; if ƒconv = 8 MHz 7 ; if ƒconv ≠ 8 MHz n2 = 0 ; if external reference mode is selected 3 ; if tREF = 0 µs or reference is programmed for power up all the time. 1 + tREF /125 ns; if tREF ≠ 0 µs and reference needs to power down between conversions. tREF is the reference power up delay time. REG−00 of PAGE−01 is updated for PORT SCAN Mode Waiting for Host to Write into REG−00 of PAGE−01 DAV (PAGE01H,REG01H [D15−D14 = 01]) 70 Reading BAT− Data Register SS DEACTIVATED Wait for Reference Power-Up Delay in Case of Internal Ref Mode if Applicable Sample,Conversion & Averaging for BAT & AUX1 & AUX2 input Reading AUX1− Data Register Reading AUX2− Data Register Waiting for Host to Write into REG−00 of PAGE−01 t OSC www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 ADC CHANNEL DIGITAL FILTER FREQUENCY RESPONSES Figure 35. Pass-Band Frequency Response of ADC Digital Filter Figure 36. Frequency Response of ADC High-Pass Filter (Fcutoff = 0.0045 Fs) 71 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Figure 37. Frequency Response of ADC High-Pass Filter (Fcutoff = 0.0125 Fs) Figure 38. Frequency Response of ADC High-Pass Filter (Fcutoff = 0.025 Fs) 72 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 DAC CHANNEL DIGITAL FILTER FREQUENCY RESPONSES Figure 39. DAC Channel Digital Filter Frequency Response Figure 40. DAC Channel Digital Filter Pass-Band Frequency Response 73 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Figure 41. Default Digital Audio Effects Filter Frequency Response at 48 Ksps Figure 42. De-Emphasis Filter Response at 32 Ksps 74 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Figure 43. De-Emphasis Error at 32 Ksps Figure 44. De-Emphasis Filter Frequency Response at 44.1 Ksps 75 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Figure 45. De-Emphasis Error at 44.1 Ksps Figure 46. De-Emphasis Frequency Response at 48 Ksps 76 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 Figure 47. De-Emphasis Error at 48 Ksps 77 www.ti.com SLAS418B − FEBRUARY 2004 − REVISED MAY 2005 PLL PROGRAMMING The on-chip PLL in the AIC28 can be used to generate sampling clocks from a wide range of MCLK’s available in a system. The PLL works by generating oversampled clocks with respect to Fsref (44.1 kHz or 48 kHz). Frequency division generates all other internal clocks. Table 6 and Table 7 gives a sample programming for PLL registers for some standard MCLK’s when PLL is required. Whenever the MCLK is of the form of N × 128 × Fsref (N=2,3,...), the PLL is not required. Table 6. Fsref = 44.1 kHz MCLK (MHz) P J D ACHIEVED FSREF % ERROR 2.8224 1 32 0 44100.00 0.0000 5.6448 1 16 0 44100.00 0.0000 12 1 7 5264 44100.00 0.0000 13 1 6 9474 44099.71 0.0007 0.0000 16 1 5 6448 44100.00 19.2 1 4 7040 44100.00 0.0000 19.68 1 4 5893 44100.30 −0.0007 48 4 7 5264 44100.00 0.0000 Table 7. Fsref = 48 kHz 78 MCLK (MHz) P J D ACHIEVED FSREF % ERROR 2.048 1 48 0 48000.00 0.0000 3.072 1 32 0 48000.00 0.0000 4.096 1 24 0 48000.00 0.0000 6.144 1 16 0 48000.00 0.0000 8.192 1 12 0 48000.00 0.0000 12 1 8 1920 48000.00 0.0000 13 1 7 5618 47999.71 0.0006 16 1 6 1440 48000.00 0.0000 19.2 1 5 1200 48000.00 0.0000 19.68 1 4 9951 47999.79 0.0004 48 4 8 1920 48000.00 0.0000 PACKAGE OPTION ADDENDUM www.ti.com 26-Mar-2007 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty TLV320AIC28IRGZ ACTIVE QFN RGZ 48 52 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TLV320AIC28IRGZG4 ACTIVE QFN RGZ 48 52 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR TLV320AIC28IRGZR ACTIVE QFN RGZ 48 2500 Green (RoHS & no Sb/Br) Call TI Level-2-260C-1 YEAR TLV320AIC28IRGZRG4 ACTIVE QFN RGZ 48 2500 Green (RoHS & no Sb/Br) Call TI Level-2-260C-1 YEAR TLV320AIC28RGZ PREVIEW QFN RGZ 48 TBD Call TI Call TI TLV320AIC28RGZR PREVIEW QFN RGZ 48 TBD Call TI Call TI Lead/Ball Finish MSL Peak Temp (3) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. 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Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 19-Mar-2008 TAPE AND REEL INFORMATION *All dimensions are nominal Device TLV320AIC28IRGZR Package Package Pins Type Drawing QFN RGZ 48 SPQ Reel Reel Diameter Width (mm) W1 (mm) 2500 330.0 16.4 Pack Materials-Page 1 A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 7.3 7.3 1.5 12.0 16.0 Q2 PACKAGE MATERIALS INFORMATION www.ti.com 19-Mar-2008 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TLV320AIC28IRGZR QFN RGZ 48 2500 333.2 345.9 28.6 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. 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