Burr-Brown Products from Texas Instruments PCM1850 PCM1851 SLES108 − MARCH 2004 24-BIT, 96-kHz STEREO A/D CONVERTER WITH 6 y 2-CHANNEL MUX AND PGA FEATURES D Multiplexer and Programmable-Gain Amplifier (PGA) − 6×2-Channel Single-Ended Inputs − Multiplexed Output − Maximum Input Level: 2.4 V rms − Input Resistance: 50 kΩ, Minimum − PGA Gain: 11 to –11 dB Range, 0.5 dB/Step D 24-Bit Delta-Sigma Stereo A/D Converter D Antialiasing Filter Included D Oversampling Decimation Filter − − − − D D D D D D Lead-Free Product Oversampling Frequency: ×64 Pass-Band Ripple: ±0.05 dB Stop-Band Attenuation: –65 dB On-Chip High-Pass Filter: 0.91 Hz (48 kHz) D High Performance − THD+N: 0.0023% (Typically) − SNR: 101 dB (Typically) − Dynamic Range: 102 dB (Typically) D PCM Audio Interface − Master/Slave Mode Selectable − Data Formats: 24-Bit Left Justified, 24-Bit I2S, 16-, 24-Bit Right Justified Mode Control by Serial Interface: − With SPI Control (PCM1850) − With I2C Control (PCM1851) Sampling Rate: 16–96 kHz System Clock: 256 fs, 384 fs, 512 fs, 768 fs Dual Power Supplies: 5 V for Analog, 3.3 V for Digital Package: 32-Pin TQFP APPLICATIONS D DVD/HDD/DVD+HDD Recorder D AV Amplifier Receiver D CD Recorder D MD Recorder D Multi-Track Recorder D Electric Musical Instrument DESCRIPTION The PCM1850/1851 is a high-performance, low-cost, single-chip stereo analog-to-digital converter with a single-ended analog front end that consists of a 6-stereo-input multiplexer and wide-range PGA. The PCM1850/1851 includes a delta-sigma modulator with 64-times oversampling, a digital decimation filter and a low-cut filter that removes the dc component of the input signal. For various applications, the PCM1850/1851 supports two modes (master and slave) and four data formats through a serial control interface, SPI for the PCM1850 and I2C for the PCM1851, respectively. The PCM1850/1851 is suitable for a wide variety of cost-sensitive DVD/CD/MD recorder and receiver applications where good performance and operation from a 5-V analog supply and 3.3-V digital supply is required. The PCM1850/1851 is fabricated using a highly advanced CMOS process and is available in a small 32-pin TQFP package. ORDERING INFORMATION PRODUCT PACKAGE PACKAGE CODE OPERATION TEMPERATURE RANGE PACKAGE MARKING PCM1850PJT 32 Lead TQFP 32-Lead 32PJT –40°C 40°C to 85°C PCM1850 PCM1851PJT 32 Lead TQFP 32-Lead 32PJT –40°C 40°C to 85°C PCM1851 ORDERING NUMBER TRANSPORT MEDIA PCM1850PJT Tray PCM1850PJTR Tape and reel PCM1851PJT Tray PCM1851PJTR Tape and reel 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. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2004, Texas Instruments Incorporated PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 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. BLOCK DIAGRAM VINL1 VINL2 VINL3 VINL4 VINL5 VINL6 MOUTL Single-Ended MUX and PGA Reference VINR1 VINR2 VINR3 VINR4 VINR5 VINR6 MOUTR Single-Ended MUX and PGA VCC OVER Control Data Interface MS (ADR)(1) MD (SDA)(1) MC (SCL)(1) Delta-Sigma Modulator AGND DGND TEST0 TEST1 RST Clock and Timing Control Power Supply (1) Audio Data Interface Decimation Filter with High-Pass Filter VREF1 VREFS VREF2 BCK LRCK DOUT Delta-Sigma Modulator SCKI VDD PCM1850 (PCM1851) PIN ASSIGNMENTS VINR6 VINL6 VINR5 VINL5 VINR4 VINL4 VINR3 VINL3 PCM1851 (TOP VIEW) VINR6 VINL6 VINR5 VINL5 VINR4 VINL4 VINR3 VINL3 PCM1850 (TOP VIEW) 24 23 22 21 20 19 18 17 16 26 15 27 14 28 13 29 12 30 11 31 10 32 9 2 3 4 5 6 7 8 LRCK BCK DOUT OVER DGND VDD SCKI TEST0 1 2 24 23 22 21 20 19 18 17 25 VINR2 VINL2 VINR1 VINL1 MOUTL MOUTR RST TEST1 VREFS VREF1 VREF2 Vcc AGND ADR SCL SDA 25 16 26 15 27 14 28 13 29 12 30 11 31 10 32 9 1 2 3 4 5 6 7 8 LRCK BCK DOUT OVER DGND VDD SCKI TEST0 VREFS VREF1 VREF2 Vcc AGND MS MC MD VINR2 VINL2 VINR1 VINL1 MOUTL MOUTR RST TEST1 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 Terminal Functions PCM1850 TERMINAL I/O DESCRIPTIONS NAME PIN AGND 29 — Analog GND BCK 2 I/O Bit clock input/output(1) DGND 5 — Digital GND DOUT 3 O Audio data output LRCK 1 I/O Sampling clock input/output(1) MC 31 I Mode control clock input(2) MD 32 I Mode control data input(2) MOUTL 12 O Multiplexer output, L-channel MOUTR 11 O Multiplexer output, R-channel MS 30 I Mode control select input(3) OVER 4 O Overflow flag RST 10 I Reset, active LOW(3) SCKI 7 I System clock input; 256 fS, 384 fS, 512 fS or 768 fS(2) TEST0 8 I Test 0, must be connected to GND(3) TEST1 9 I Test 1, must be connected to GND(3) VCC 28 — Analog power supply, 5-V VDD 6 — Digital power supply, 3.3-V VINL1 13 I Analog input 1, L-channel VINL2 15 I Analog input 2, L-channel VINL3 17 I Analog input 3, L-channel VINL4 19 I Analog input 4, L-channel VINL5 21 I Analog input 5, L-channel VINL6 23 I Analog input 6, L-channel VINR1 14 I Analog input 1, R-channel VINR2 16 I Analog input 2, R-channel VINR3 18 I Analog input 3, R-channel VINR4 20 I Analog input 4, R-channel VINR5 22 I Analog input 5, R-channel VINR6 24 I Analog input 6, R-channel VREFS 25 — Reference S decoupling capacitor (= 0.5 VCC) VREF1 26 — Reference 1 decoupling capacitor (= 0.5 VCC) VREF2 27 — Reference 2 decoupling capacitor (= VCC) (1) Schmitt-trigger input with internal pulldown resistor (50 kΩ, typically) Schmitt-trigger input, 5-V tolerant (3) Schmitt-trigger input with internal pulldown resistor (50 kΩ, typically), 5-V tolerant (2) 3 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 Terminal Functions PCM1851 TERMINAL (1) I/O DESCRIPTIONS NAME PIN ADR 30 AGND 29 — Analog GND BCK 2 I/O Bit clock input/output(2) DGND 5 — Digital GND DOUT 3 O Audio data output LRCK 1 I/O Sampling clock input/output(2) I Mode control address select input (1) MOUTL 12 O Multiplexer output, L-channel MOUTR 11 O Multiplexer output, R-channel OVER 4 O Overflow flag RST 10 I SCKI 7 I System clock input; 256 fS, 384 fS, 512 fS or 768 fS(3) SCL 31 I Mode control clock input(3) SDA 32 I/O TEST0 8 I Test 0, must be connected to GND (1) TEST1 9 I Test 1, must be connected to GND (1) VCC 28 — Analog power supply, 5-V Reset, active LOW(1) Mode control data input/output(4) VDD 6 — Digital power supply, 3.3-V VINL1 13 I Analog input 1, L-channel VINL2 15 I Analog input 2, L-channel VINL3 17 I Analog input 3, L-channel VINL4 19 I Analog input 4, L-channel VINL5 21 I Analog input 5, L-channel VINL6 23 I Analog input 6, L-channel VINR1 14 I Analog input 1, R-channel VINR2 16 I Analog input 2, R-channel VINR3 18 I Analog input 3, R-channel VINR4 20 I Analog input 4, R-channel VINR5 22 I Analog input 5, R-channel VINR6 24 I Analog input 6, R-channel VREFS 25 — Reference S decoupling capacitor (= 0.5 VCC) VREF1 26 — Reference 1 decoupling capacitor (= 0.5 VCC) VREF2 27 — Reference 2 decoupling capacitor (= VCC) Schmitt-trigger input with internal pulldown resistor (50 kΩ, typically), 5-V tolerant Schmitt-trigger input with internal pulldown resistor (50 kΩ, typically) (3) Schmitt-trigger input, 5-V tolerant (4) Schmitt-trigger input/open-drain LOW output, 5-V tolerant (2) 4 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range unless otherwise noted(1) Supply voltage: VCC –0.3 V to 6.5 V Supply voltage: VDD –0.3 V to 4 V ±0.1 V Ground voltage differences: AGND, DGND Digital input voltage: LRCK, BCK, DOUT, OVER –0.3 V to (VDD + 0.3 V) < 4 V Digital input voltage: RST, SCKI, MS (ADR)(2), MC (SCL)(2), MD (SDA)(2), TEST0, TEST1 –0.3 V to 6.5 V Analog input voltage: VINL1–6, VINR1–6 –3 V to (VCC + 3 V) < 9 V Analog input voltage: MOUTL, MOUTR, VREF1, VREF2, VREFS –0.3 V to (VCC + 0.3 V) < 6.5 V ±10 mA Input current (any pins except supplies) Ambient temperature under bias –40°C to 125°C Storage temperature –55°C to 150°C Junction temperature 150°C Lead temperature (soldering) 260°C, 5 s Package temperature (IR reflow, peak) 260°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) PCM1850 (PCM1851) ELECTRICAL CHARACTERISTICS All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted PARAMETER TEST CONDITIONS PCM1850PJT, PCM1851PJT MIN TYP MAX UNIT DIGITAL INPUT/OUTPUT DATA FORMAT Left-justified, I2S, right-justified Audio data interface format Audio data bit length 16, 24 Audio data format fS MSB-first, 2s complement Sampling frequency System clock frequency bits 16 48 96 256 fS 4.096 12.288 24.576 384 fS 6.144 18.432 36.864 512 fS 8.192 24.576 49.152 768 fS 12.288 36.864 — kHz MHz INPUT LOGIC VIH (1) VIL (1) VIH (2) (3) Input logic level VIL (2) (3) IIH (2) IIL (2) IIH (1) (3) IIL (1) (3) (1) Pins 1, 2 VDD 0 0.8 2 5.5 0 0.8 ±10 VIN = VDD Input logic current ±10 VIN = 0 VIN = VDD VIN = 0 VDC 65 100 µA A ±10 2: LRCK, BCK (In slave mode, Schmitt-trigger input, with 50-kΩ typical pulldown resistor) (2) Pins 7, 31, 32: SCKI, MC/SCL (PCM1850/1851), MD/SDA (PCM1850/1851) (Schmitt-trigger input, 5-V tolerant) (3) Pins 8–10, 30: TEST0, TEST1, RST, MS/ADR (PCM1850/1851) (Schmitt-trigger input, with 50-kΩ typical pulldown resistor, 5-V tolerant) 5 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 ELECTRICAL CHARACTERISTICS (Continued) All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted PARAMETER TEST CONDITIONS PCM1850PJT, PCM1851PJT MIN TYP MAX UNIT OUTPUT LOGIC VOH (1) VOL(1) (2) Output logic level IOUT = –4 mA 2.8 IOUT = 4 mA 0.5 VDC AFE MULTIPLEXER Input channels 6 Input level for full scale 2 Center voltage (VREF1) Selected channel Center voltage (VREFS) Unselected channel Input impedance 2.4 Vrms 0.5 VCC V 0.5 VCC V Selected channel 50 169 Unselected channel 50 57 kΩ AFE PGA Gain range –11 Gain step 0 11 0.5 Monotonicity Antialiasing filter frequency response dB dB Specified –3 dB, PGA gain = –5.5 dB 300 kHz 0.6 VCC Vp-p MONITOR OUTPUT Output level for full scale Output load THD+N (3) (4) S/N ratio (3) (4) Gain error (3) (4) AC-coupled, >10 kΩ AC-coupled 10 kΩ AC-coupled, 10 kΩ, 3 Vp-p output, 0.0016% AC-coupled, 10 kΩ 104 dB –3 % of FSR 0.5 VCC V AC-coupled, 10 kΩ Center voltage ADC Resolution Full scale input voltage 24 bits 0.6 VCC Vp-p ACCURACY Gain mismatch, channel-to-channel ±1 ±3 % of FSR Gain error ±2 ±5 % of FSR Bipolar zero error High-pass filter bypass (1) ±2 % of FSR Pins 1–4: LRCK, BCK (in master mode), DOUT, OVER (2) Pin 32: SDA (PCM1851) (open-drain LOW output) (3) Analog performance specifications are tested with the System Two™ audio measurement system by Audio Precision™, using a 400-Hz HPF and 20-kHz LPF in the RMS mode at fIN = 1 kHz. (4) Reference level (0 dB) is specified as 2-V rms input on V L[1:6] and V R[1:6] pins with PGA gain of –5.5 dB. IN IN Audio Precision and System Two are trademarks of Audio Precision, Inc. 6 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 ELECTRICAL CHARACTERISTICS (Continued) All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted PARAMETER TEST CONDITIONS PCM1850PJT, PCM1851PJT MIN TYP MAX fS = 48 kHz, VIN = –0.5 dB (1.89 Vrms) 0.0023% 0.004% fS = 96 kHz(4), VIN = –0.5 dB (1.89 Vrms) 0.0027% fS = 48 kHz, VIN = –60 dB (2 mVrms) 1% UNIT DYANAMIC PEFORMANCE(1) (2) THD+N (3) THD+N (3) Dynamic range (3) S/N ratio (3) Channel separation (between L L-ch ch and R-ch) (3) Channel separation (among channels) (5) fS = 96 kHz(4), VIN = –60 dB (2 mVrms) fS = 48 kHz, A-weighted 1% 96 fS = 96 kHz(4), A-weighted fS = 48 kHz, A-weighted fS = 96 96 101 dB 102 92 kHz(4) fS = 48 kHz dB 102 fS = 96 kHz(4), A-weighted fS = 48 kHz 102 98 dB 100 90 fS = 96 kHz(4) 96 dB 96 DIGITAL FILTER PERFORMANCE Pass band 0.454 fS Stop band 0.583 fS Hz ±0.05 Pass-band ripple Stop-band attenuation –65 Delay time HPF frequency response –3 dB Hz dB dB 17.4/fS s 0.019 fS mHz POWER SUPPLY REQUIREMENTS VCC VDD 4.5 5 5.5 VDC 2.7 3.3 3.6 VDC Operation 28 35 mA Power down (7) 190 fS = 48 kHz 6 fS = 96 kHz (4) 12 Voltage range ICC Supply current (6) IDD Power dissipation, dissipation operation Power dissipation, dissipation power down (7) Power down (7), PCM1850 80 Power down (7), PCM1851 280 fS = 48 kHz 160 fS = 96 kHz (4) 180 PCM1850 1.2 PCM1851 1.9 µA 10 mA µA 208 mW TEMPERATURE RANGE Operation temperature Thermal resistance (θJA) (1) (2) (3) (4) (5) (6) (7) –40 85 80 °C °C/W Analog performance specifications are tested with the System Two™ audio measurement system by Audio Precision™, using a 400-Hz HPF and 20-kHz LPF in the RMS mode at fIN = 1 kHz. Reference level (0 dB) is specified as 2-V rms input on VINL[1:6] and VINR[1:6] pins with PGA gain of –5.5 dB. Unselected channel inputs are terminated to AGND with 0.33 µF. fS = 96 kHz, system clock = 256 fS. 2-V rms input is applied to all unselected channels, and input of selected channel is terminated to AGND with 0.33 µF. Minimum load on DOUT (pin 3), BCK (pin 2), LRCK (pin 1) Halt SCKI, BCK, LRCK. 7 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 TYPICAL PERFORMANCE CURVES OF INTERNAL FILTER DIGITAL FILTER Decimation Filter Frequency Response AMPLITUDE vs FREQUENCY AMPLITUDE vs FREQUENCY 0 50 −10 −20 0 Amplitude – dB Amplitude – dB −30 −50 −100 −40 −50 −60 −70 −80 −150 −90 −200 0 8 16 Frequency [× fS] 24 −100 0.00 32 Figure 1. Overall Characteristics 0.25 0.50 1.00 Figure 2. Stop-Band Attenuation Characteristics AMPLITUDE vs FREQUENCY AMPLITUDE vs FREQUENCY 0.2 0 –4.13 dB at 0.5× −1 0.0 −2 −3 −0.2 Amplitude − dB Amplitude – dB 0.75 Frequency [× fS] −0.4 −0.6 −4 −5 −6 −7 −8 −0.8 −9 −1.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 Frequency [× fS] Figure 3. Pass-Band Ripple Characteristics −10 0.45 0.47 0.49 0.51 0.53 0.55 Frequency [× fS] Figure 4. Transition-Band Characteristics All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted 8 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 High-Pass Filter Frequency Response AMPLITUDE vs FREQUENCY 0.2 AMPLITUDE vs FREQUENCY 0 −10 −20 −30 −0.2 Amplitude – dB Amplitude – dB 0.0 −0.4 −0.6 −40 −50 −60 −70 −80 −0.8 −90 −1.0 0 1 2 3 −100 0.0 4 0.1 0.2 0.3 0.4 Frequency [× fS/1000] Frequency [× fS/1000] Figure 5. HPF Pass-Band Characteristics Figure 6. HPF Stop-Band Characteristics ANALOG FILTER Antialiasing Filter Frequency Response (at PGA gain = –5.5 dB) AMPLITUDE vs FREQUENCY 0 −5.6 −5 −5.7 −10 −5.8 −15 Amplitude – dB Amplitude – dB −5.5 −5.9 −6.0 −6.1 −25 −30 −35 −6.3 −40 −6.4 −45 1 10 100 f – Frequency – kHz Figure 7. Antialiasing Filter Pass-Band Characteristics 1k f–3dB = 300 kHz −20 −6.2 −6.5 0.1 AMPLITUDE vs FREQUENCY −50 1 10 100 1k 10k f – Frequency – kHz Figure 8. Antialiasing Filter Stop-Band Characteristics All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted 9 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 TYPICAL PERFORMANCE CURVES AT PGA GAIN = –5.5 dB TOTAL HARMONIC DISTORTION + NOISE vs FREE-AIR TEMPERATURE DYNAMIC RANGE and SNR vs FREE-AIR TEMPERATURE 107 106 Dynamic Range and SNR – dB THD+N – Total Harmonic Distortion + Noise – % 0.004 0.003 0.002 105 104 103 Dynamic Range 102 SNR 101 100 99 98 0.001 −40 −15 10 35 60 97 −40 85 TA – Free-Air Temperature – °C −15 Figure 9 35 60 DYNAMIC RANGE and SNR vs SUPPLY VOLTAGE 0.004 107 Dynamic Range and SNR – dB 106 0.003 0.002 105 104 103 Dynamic Range 102 101 SNR 100 99 98 0.001 4.5 4.7 4.9 5.1 VCC – Supply Voltage – V Figure 11 5.3 5.5 97 4.5 4.7 4.9 5.1 5.3 VCC – Supply Voltage – V Figure 12 All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted 10 85 Figure 10 TOTAL HARMONIC DISTORTION + NOISE vs SUPPLY VOLTAGE THD+N – Total Harmonic Distortion + Noise – % 10 TA – Free-Air Temperature – °C 5.5 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 TOTAL HARMONIC DISTORTION + NOISE vs fSAMPLE CONDITION DYNAMIC RANGE and SNR vs fSAMPLE CONDITION 107 106 Dynamic Range and SNR – dB THD+N – Total Harmonic Distortion + Noise – % 0.004 0.003 0.002 105 104 103 Dynamic Range 102 SNR 101 100 99 98 0.001 16 36 56 76 97 96 16 fSAMPLE Condition – kHz 36 56 76 96 fSAMPLE Condition – kHz Figure 14 Figure 13 OUTPUT SPECTRUM AMPLITUDE vs FREQUENCY 0 AMPLITUDE vs FREQUENCY 0 Input Level = –60 dB Data Points = 8192 −20 −20 −40 Amplitude – dB Amplitude – dB −40 −60 −80 −60 −80 −100 −100 −120 −120 −140 Input Level = –0.5 dB Data Points = 8192 0 5 10 f – Frequency – kHz Figure 15 15 20 −140 0 5 10 15 20 f – Frequency – kHz Figure 16 All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted 11 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 TOTAL HARMONIC DISTORTION + NOISE vs SIGNAL LEVEL THD+N – Total Harmonic Distortion + Noise – % 100 10 1 0.1 0.01 0.001 −100 −90 −80 −70 −60 −50 −40 −30 −20 −10 0 Signal Level – dB Figure 17 SUPPLY CURRENT PGA GAIN LINEARITY SUPPLY CURRENT vs fSAMPLE CONDITION OVERALL GAIN vs GAIN SETTING 30 11 9 7 5 20 Overall Gain – dB ICC and IDD – Supply Current – mA ICC 25 15 IDD 10 3 1 −1 −3 −5 −7 5 −9 0 16 36 56 76 fSAMPLE Condition – kHz Figure 18 96 −11 −11 −9 −7 −5 −3 −1 1 3 5 7 9 11 Gain Setting – dB Figure 19 All specifications at TA = 25°C, VCC = 5 V, VDD = 3.3 V, master mode, fS = 48 kHz, system clock = 256 fS, 24-bit data, unless otherwise noted 12 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 SYSTEM CLOCK The PCM1850/1851 supports 256 fS, 384 fS, 512 fS, and 768 fS as the system clock, where fS is the audio sampling frequency. The system clock must be supplied on SCKI (pin 7). The PCM1850/1851 has a system clock detection circuit which automatically senses if the system clock is operating at 256 fS, 384 fS, 512 fS or 768 fS in slave mode. In master mode, the system clock frequency must be selected by mode control via the serial port. The 768-fS system clock is not available in master mode or for fS = 88.2 kHz and 96 kHz in the slave mode. The system clock is divided into 128 fS and 64 fS automatically, and these frequencies are used to operate the digital filter and the delta-sigma modulator, respectively. Table 1 shows the relationship of typical sampling frequency to system clock frequency, and Figure 20 shows system clock timing. Table 1. Sampling Frequency and System Clock Frequency SAMPLING RATE FREQUENCY Q (kHz) (1) SYSTEM CLOCK FREQUENCY (MHz) 256 fS 384 fS 512 fS 768 fS (1) 32 8.192 12.288 16.384 24.576 44.1 11.2896 16.9344 22.5792 33.8688 48 12.288 18.432 24.576 36.864 64 16.384 24.576 32.768 49.152 88.2 22.5792 33.8688 45.1584 — 96 24.576 36.864 49.152 — Slave mode only t(SCKH) H 2.0 V SCKI 0.8 V L t(SCKL) SYMBOL PARAMETER MIN MAX UNIT tSCKH System clock pulse duration, HIGH 8 ns tSCKL System clock pulse duration, LOW 8 ns Figure 20. System Clock Timing 13 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 POWER-ON RESET SEQUENCE The PCM1850/1851 has an internal power-on reset circuit, and initialization (reset) is performed automatically at the time that the power supply (VDD) exceeds 2.2 V (typ). While VDD < 2.2 V (typ) and for 1024 system clocks after VDD > 2.2 V (typ), the PCM1850/1851 stays in the reset state and the digital output is forced to zero. The digital output is valid after the reset state is released and the time of 4500/fS has passed. At the moment of the power-on reset release, the PCM1850/1851 does not need a system clock. Figure 21 illustrates the internal power-on reset timing and the digital output for power-on reset. VDD 2.6 V 2.2 V 1.8 V Reset Release From Reset 1024 System Clocks 4500/fS Internal Reset System Clock DOUT Zero Data Figure 21. Internal Power-On Reset Timing 14 Normal Data PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 ANALOG FRONT END The PCM1850/1851 has a built-in analog front-end circuit, which is shown in the block diagram of Figure 22. Selection of the multiplexer input and PGA gain is controlled by mode control via the serial port as shown in Table 2 and Table 3. The change of the input selection and the gain selection is performed immediately after the serial control packet for the change is sent. A popping noise or other unexpected transient response could be generated in the audio signal during channel and gain change. Because the PCM1850/1851 has no zero-cross detection and no other buffering capability for channel and gain change, appropriate data handling in the digital domain is recommended to control transients. The PCM1850/1851 analog front end permits only ac input via an input capacitor; dc input is prohibited. A signal source resistance of less than 1 kΩ is recommended for the VINxx pins. All unselected channel inputs are terminated VREFS (= 0.5 VCC) using a resistor, typically 57 kΩ. The PCM1850/1851 employs MOUTL/R pins (pins 12 and 11) to monitor the multiplexer output. The load on these pins must be ac-coupled and not less than 10 kΩ. The full-scale output level is typically 0.6 VCC. VINL1 R VINL2 R VINL6 R PGA (11 dB to –11 dB) with MUX R G = –1 LIN+ R LIN– VREFS (= 0.5 VCC) VREF1 (= 0.5 VCC) MOUTL Figure 22. Analog Front-End Block Diagram (L-channel) Table 2. Multiplexer Input Selection CH2 CH1 CH0 0 0 0 CHANNEL Mute 0 0 1 Channel 1 (default) 0 1 0 Channel 2 0 1 1 Channel 3 1 0 0 Channel 4 1 0 1 Channel 5 1 1 0 Channel 6 1 1 1 Mute 15 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 Table 3. PGA Gain Selection PG5 PG4 PG3 PG2 PG1 PG0 PGA GAIN [dB] RIN [kΩ, Typical] 0 0 1 0 1 0 –11 (default) 201 0 0 1 0 1 1 –10.5 199 0 0 1 1 0 0 –10 196 0 0 1 1 0 1 –9.5 193 0 0 1 1 1 0 –9 190 0 0 1 1 1 1 –8.5 188 0 1 0 0 0 0 –8 185 0 1 0 0 0 1 –7.5 181 0 1 0 0 1 0 –7 178 0 1 0 0 1 1 –6.5 175 0 1 0 1 0 0 –6 172 0 1 0 1 0 1 –5.5 169 0 1 0 1 1 0 –5 165 0 1 0 1 1 1 –4.5 162 0 1 1 0 0 0 –4 158 0 1 1 0 0 1 –3.5 155 0 1 1 0 1 0 –3 151 0 1 1 0 1 1 –2.5 147 0 1 1 1 0 0 –2 144 0 1 1 1 0 1 –1.5 140 0 1 1 1 1 0 –1 136 0 1 1 1 1 1 –0.5 133 1 0 0 0 0 0 0 129 1 0 0 0 0 1 0.5 125 1 0 0 0 1 0 1 122 1 0 0 0 1 1 1.5 118 1 0 0 1 0 0 2 114 1 0 0 1 0 1 2.5 111 1 0 0 1 1 0 3 107 1 0 0 1 1 1 3.5 103 1 0 1 0 0 0 4 100 1 0 1 0 0 1 4.5 96 1 0 1 0 1 0 5 93 1 0 1 0 1 1 5.5 89 1 0 1 1 0 0 6 86 1 0 1 1 0 1 6.5 83 1 0 1 1 1 0 7 80 1 0 1 1 1 1 7.5 77 1 1 0 0 0 0 8 73 1 1 0 0 0 1 8.5 70 1 1 0 0 1 0 9 68 1 1 0 0 1 1 9.5 65 1 1 0 1 0 0 10 62 1 1 0 1 0 1 10.5 59 1 1 0 1 1 0 11 57 258 1 ) 10ǒ GAINń20Ǔ The PCM1850/1851 becaomes mute for PG[5:0] values other than those listed. NOTE: RIN(kW, typical) + 16 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 SERIAL AUDIO DATA INTERFACE The PCM1850/1851 interfaces with the audio system through BCK (pin 2), LRCK (pin 1), and DOUT (pin 3). Interface Mode The PCM1850/1851 supports both master and slave modes as interface modes, and they are selected by mode control via the serial port as shown in Table 4. In master mode, the PCM1850/1851 provides the timing for serial audio data communications between the PCM1850/1851 and the digital audio processor or external circuit. While in slave mode, the PCM1850/1851 receives the timing for data transfer from an external controller. Table 4. Interface Mode MD1 MD0 INTERFACE MODE 0 0 Slave mode (256 fS, 384 fS, 512 fS, 768 fS) (default) 0 1 Master mode (256 fS) 1 0 Master mode (384 fS) 1 1 Master mode (512 fS) Master Mode In master mode, BCK and LRCK work as output pins, and these pins are controlled by timing which is generated in the clock and timing control circuit of the PCM1850/1851. The frequency of BCK is fixed at 64 × LRCK. A 768-fS system clock is not available in master mode. Slave Mode In slave mode, BCK and LRCK work as input pins. The PCM1850/1851 accepts the 64 BCK/LRCK or 48 BCK/LRCK (only for 384 fS SCKI) format. A 768-fS system clock is not available for fS = 88.2 kHz and 96 kHz in slave mode. Data Format The PCM1850/1851 supports four audio data formats in both master and slave modes, and they are selected by mode control via the serial port as shown in Table 5. Figure 23 illustrates the data formats in both slave and master modes. Table 5. Data Format FORMAT NO. FMT2 FMT1 FMT0 FORMAT 0 1 0 1 Left-justified, 24-bit 1 1 0 0 I2S, 24-bit, (default) 2 0 0 0 Right-justified, 24-bit 3 0 1 1 Right-justified, 16-bit 17 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 FORMAT 0: FMT[2:0] = 101b 24-Bit, MSB-First, Left-Justified LRCK Left-Channel Right-Channel BCK DOUT 1 2 3 22 23 24 MSB 1 LSB 2 3 22 23 24 MSB 1 LSB FORMAT 1: FMT[2:0] = 100b 24-Bit, MSB-First, I2S LRCK Left-Channel Right-Channel BCK DOUT 1 2 3 22 23 24 1 LSB MSB 2 3 22 23 24 LSB MSB FORMAT 2: FMT[2:0] = 000b 24-Bit, MSB-First, Right-Justified Left-Channel LRCK Right-Channel BCK DOUT 24 1 2 3 22 23 24 MSB LSB 1 2 3 22 23 24 MSB LSB FORMAT 3: FMT[2:0] = 011b 16-Bit, MSB-First, Right-Justified Left-Channel LRCK Right-Channel BCK DOUT 16 1 2 MSB 3 14 15 16 LSB 1 2 3 14 15 16 MSB Figure 23. Audio Data Format (LRCK, BCK Work as Inputs in Slave Mode and Outputs in Master Mode) 18 LSB PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 Interface Timing Figure 24 and Figure 25 illustrate the interface timing in slave and master modes, respectively. t(LRCP) 1.4 V LRCK t(BCKL) t(LRSU) t(BCKH) t(LRHD) 1.4 V BCK t(CKDO) t(BCKP) t(LRDO) 0.5 VDD DOUT SYMBOL PARAMETER MIN TYP MAX UNIT t(BCKP) BCK period 150 ns t(BCKH) BCK pulse duration, HIGH 60 ns t(BCKL) BCK pulse duration, LOW 60 ns t(LRSU) LRCK setup time to BCK rising edge 20 ns t(LRHD) LRCK hold time to BCK rising edge 20 ns µs t(LRCP) LRCK period t(CKDO) Delay time, BCK falling edge to DOUT valid –10 10 20 ns t(LRDO) Delay time, LRCK edge to DOUT valid –10 20 ns tr Rise time of all signals 10 ns tf Fall time of all signals 10 ns NOTE: Timing measurement reference level is (VIH + VIL) / 2. Rise and fall times are measured from 10% to 90% of IN/OUT signal swing. Load capacitance of DOUT is 20 pF. Figure 24. Audio Data Interface Timing (Slave Mode: LRCK, BCK Work as Inputs) 19 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 t(LRCP) 0.5 VDD LRCK t(BCKL) t(BCKH) t(CKLR) 0.5 VDD BCK t(CKDO) t(BCKP) t(LRDO) 0.5 VDD DOUT SYMBOL PARAMETER MIN TYP MAX UNIT t(BCKP) BCK period 150 1/(64 fS) 1000 ns t(BCKH) BCK pulse duration, HIGH 60 0.5 t(BCKP) 400 ns t(BCKL) BCK pulse duration, LOW 60 0.5 t(BCKP) 400 ns t(CKLR) Delay time, BCK falling edge to LRCK valid –10 20 ns t(LRCP) LRCK period 10 1/fS 60 µs t(CKDO) Delay time, BCK falling edge to DOUT valid –10 20 ns t(LRDO) Delay time, LRCK edge to DOUT valid –10 20 ns tr Rise time of all signals 10 ns tf Fall time of all signals 10 ns NOTE: Timing measurement reference level is (VIH + VIL) / 2. Rise and fall times are measured from 10% to 90% of IN/OUT signal swing. Load capacitance of all signals is 20 pF. Figure 25. Audio Data Interface Timing (Master Mode: LRCK, BCK Work as Outputs) 20 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 SYNCHRONIZATION WITH DIGITAL AUDIO SYSTEM In slave mode, the PCM1850/1851 operates under LRCK, synchronized with system clock SCKI. The PCM1850/1851 does not need a specific phase relationship between LRCK and SCKI, but does require the synchronization of LRCK and SCKI. If the relationship between LRCK and SCKI changes more than ±6 BCKs for 64 BCKs/frame (±5 BCKs for 48 BCKs/frame) during one sample period due to LRCK or SCKI jitter, internal operation of the ADC halts within 1/fS and digital output is forced into the BPZ code until resynchronization between LRCK and SCKI is completed. In the case of changes less than ±5 BCKs for 64 BCKs/frame (±4BCKs for 48BCK/frame), resynchronization with simultaneous discontinuity in the digital output does not occur. Figure 26 illustrates the digital output response for loss of synchronization and resynchronization. During undefined data, the PCM1850/1851 might generate some noise in the audio signal. Also, the transition of normal to undefined data and undefined or zero data to normal creates a discontinuity of data in the digital output, which could generate some noise in the audio signal. It is recommended to set RST (pin 10) to LOW to get stable analog performance when the sampling rate, interface mode, or data format is changed. Synchronization Lost State of Synchronization SYNCHRONOUS Resynchronization ASYNCHRONOUS SYNCHRONOUS 1/fS DOUT NORMAL DATA UNDEFINED DATA 32/fS ZERO DATA NORMAL DATA Figure 26. ADC Digital Output for Loss of Synchronization and Resynchronization Power-Down Control RST(pin 10) controls the entire ADC operation. During reset mode, the supply current of the analog section is shut off and the digital section is initialized. DOUT (pin 3) is also disabled. Halting SCKI, BCK, and LRCK is recommended to minimize power dissipation. RST POWER-DOWN MODE LOW Reset and power-down modes HIGH Normal operation mode Overflow Flag Output The PCM1850/1851 has an output flag (pin 4) that indicates when overflow occurs in the L-channel or R-channel, and this flag remains HIGH at least during the 8192/fS time for a momentary overflow occurrence. 21 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 HPF Bypass Control The built-in HPF function for dc component rejection can be bypassed via the serial port. In bypass mode, the dc component of the analog input signal, the internal dc offset, etc., are converted and included in the digital output data. BYP HPF (HIGH-PASS FILTER) MODE 0 Normal (no dc component on DOUT) mode (default) 1 Bypass (dc component on DOUT) mode System Reset Control The system reset control is used to resynchronize the system via the serial port when the system clock frequency, interface mode, and data format are changed. Change them while SRST = LOW. If they are changed during normal operation, analog performance can be degraded. SRST SYSTEM RESET 0 Resynchronization 1 Normal operation (default) Mode Register Reset Control The MRST bit is used to reset the mode control register to its default settings via the serial port. MRST MODE REGISTER RESET 0 Set default value 1 Normal operation (default) SPI SERIAL CONTROL PORT FOR MODE CONTROL (PCM1850) The user-programmable built-in functions of the PCM1850 can be controlled through a serial control port with the SPI format. All operations for the serial control port use 16-bit data words. Figure 27 shows the control data word format. The most significant bit must be set to 0. There are seven bits, labeled IDX[6:0], that set the register index (or address) for write operations. The least significant eight bits, D[7:0], contain the data to be written to the register specified by IDX[6:0]. Figure 28 shows the functional timing diagram for writing to the serial control port. MS (pin 30) is held at a logic 1 state until a register needs to be written. To start the register write cycle, MS is set to logic 0. Sixteen clocks are then provided on MC (pin 31), corresponding to the 16 bits of the control data word on MD (pin 32). After the sixteenth clock cycle has completed, the data is latched into the indexed mode control register in the write operation. To write the next data word, MS must be set to 1 once. LSB MSB 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7 D6 D5 D4 Register Index (or Address) D3 D2 D1 D0 Register Data Figure 27. Control Data Word Format for MD MS MC MD X 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7 D6 D5 D4 D3 Figure 28. Serial Control Format 22 D2 D1 D0 X X 0 IDX6 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 CONTROL INTERFACE TIMING REQUIREMENTS (PCM1850) Figure 29 shows a detailed timing diagram for the serial control interface of the PCM1850. These timing parameters are critical for proper control port operation. t(MHH) MS 1.4 V t(MSS) t(MCL) t(MCH) t(MSH) MC 1.4 V t(MCY) LSB MD 1.4 V t(MDS) t(MDH) SYMBOL (1) PARAMETERS MIN MAX UNITS t(MCY) MC pulse cycle time 100 ns t(MCL) MC LOW level time 40 ns t(MCH) MC HIGH level time 40 ns t(MHH) MS HIGH level time 80 ns t(MSS) MS falling edge to MC rising edge 15 ns t(MSH) MS hold time(1) 15 ns t(MDH) MD hold time 15 ns t(MDS) MD setup time 15 ns MC rising edge for LSB to MS rising edge. Figure 29. PCM1850 Control Interface Timing I2C SERIAL CONTROL PORT FOR MODE CONTROL (PCM1851) The user-programmable built-in function of the PCM1851 can be controlled through the I2C-format serial control port, SDA (pin 32) and SCL (pin 31). The PCM1851 supports the I2C serial bus and the data transmission protocol for standard mode as a slave device. This protocol is explained in the I2C specification 2.0. Slave Address MSB 1 LSB 0 0 1 0 1 ADR R/nW The PCM1851 has 7 bits for its own slave address. The first six bits (MSBs) of the slave address are factory preset to 100101. The last bit of the address byte is the device select bit, which can be user-defined by the ADR pin (pin 30). A maximum of two PCM1851s can be connected on the same bus at one time. Each PCM1851 responds when it receives its own slave address. 23 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 Packet Protocol A master device must control packet protocol, which consists of start condition, slave address with read/write bit, data if write or acknowledgement if read, and stop condition. The PCM1851 supports only slave receivers, so the R/W bit must be set to 0. SDA SCL St 1−7 8 9 1−8 9 1−8 9 9 Slave Address R/W ACK DATA ACK DATA ACK ACK Start Condition Sp R/W: Read Operation if 1; Otherwise, Write Operation ACK: Acknowledgement of a Byte if 0 DATA: 8 Bits (Byte) Stop Condition Transmitter M M M S M S M S S M Data Type St Slave Address R/W ACK DATA ACK DATA ACK ACK Sp M: Master Device St: Start Condition S: Slave Device Sp: Stop Condition Figure 30. Basic I2C Framework Write Operation The PCM1851 has only the write mode. A master can write to any PCM1851 registers using single or multiple accesses. The master sends a PCM1851 slave address with a write bit, a register address, and the data. If multiple access is required, the address is that of the starting register, followed by the data to be transferred. When the data are received properly, the index register is incremented by 1 automatically. When the index register reaches 33h, the next value is 31h. When undefined registers are accessed, the PCM1851 does not send an acknowledgement. Figure 31 is a diagram of the write operation. The register address and the write data are 8 bits and MSB-first format. Transmitter M M M S M S M S M S S M Data Type St Slave Address W ACK Reg Address ACK Write Data 1 ACK Write Data 2 ACK ACK Sp M: Master Device St: Start Condition S: Slave Device ACK: Acknowledge W: Write Sp: Stop Condition Figure 31. Framework for Write Operation 24 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 TIMING DIAGRAM Start Repeated Start Stop t(D-HD) t(BUF) t(D-SU) t(SDA-R) t(SDA-F) t(P-SU) SDA t(SCL-R) t(RS-HD) t(LOW) SCL t(S-HD) t(HI) t(RS-SU) t(SCL-F) SYMBOL PARAMETER MIN MAX UNIT 100 kHz f(SCL) SCL clock frequency t(BUF) Bus free time between STOP and START condition 4.7 µs t(LOW) Low period of the SCL clock 4.7 µs t(HI) High period of the SCL clock 4 µs t(RS-SU) Setup time for START/repeated START condition 4.7 µs t(S-HD) t(RS-HD) Hold time for START/repeated START condition 4 µs t(D-SU) Data setup time 250 t(D-HD) Data hold time 0 900 ns t(SCL-R) Rise time of SCL signal 20 + 0.1CB 1000 ns ns t(SCL-F) Fall time of SCL signal 20 + 0.1CB 1000 ns t(SDA-R) Rise time of SDA signal 20 + 0.1CB 1000 ns t(SDA-F) Fall time of SDA signal 20 + 0.1CB 1000 t(P-SU) Setup time for STOP condition CB Capacitive load for SDA and SCL line VNH Noise margin at HIGH level for each connected device (including hysteresis) 400 0.2 VDD ns µs 4 pF V Figure 32. PCM1851 Control Interface Timing Requirements 25 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 MODE CONTROL REGISTERS User-Programmable Mode Control Functions The PCM1850/1851 has several user-programmable functions which are accessed via control registers. The registers are programmed using the serial control port which is discussed in the SPI Serial Control Port for Mode Control (PCM1850) and I2C Serial Control Port for Mode Control (PCM1851) sections of this data sheet. Table 6 lists the available mode control functions, along with their reset default conditions and associated register index. Register Map The mode control register map is shown in Table 7. Each register includes an index (or address) indicated by the IDX[6:0] bits B[14:8]. Table 6. User-Programmable Mode Control Functions FUNCTION RESET DEFAULT REGISTER Normal operation 31 MRST –11 dB 31 PG[5:0] CH[2:0] Mode register reset PGA gain control Multiplexer input channel control BIT(S) Channel 1 32 HPF enable 33 BYP Normal operation 33 SRST Audio interface mode control Slave 33 MD[1:0] Audio interface format control I2S 33 FMT[2:0] HPF bypass control System reset Table 7. Mode Control Register Map HEX B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 Register 31 0 0 1 1 0 0 0 1 RSV MRST PG5 Register 32 0 0 1 1 0 0 1 0 RSV RSV RSV Register 33 0 0 1 1 0 0 1 1 BYP SRST RSV MD1 NOTE: RSV bit must be always written as 0. No values can be written in address 30h. 26 B5 B4 B3 B2 B1 B0 PG4 PG3 PG2 PG1 PG0 RSV RSV CH2 CH1 CH0 MD0 FMT2 FMT1 FMT0 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 TYPICAL CIRCUIT CONNECTION DIAGRAM The following figure illustrates a typical circuit connection diagram for six stereo inputs and an analog monitor. Analog Input/Output + 24 23 22 21 20 19 18 17 VINL6 VINR5 VINL5 VINR4 VINL4 VINR3 VINL3 25 VREFS VINR2 16 26 VREF1 VINL2 15 27 VREF2 VINR1 14 28 Vcc VINL1 13 PCM1850/1851 29 AGND MOUTL 12 MOUTR 11 31 MC (SCL)(1) RST 10 32 MD (SDA)(1) TEST1 9 TEST0 30 MS (ADR)(1) SCKI Control C1 + VDD + 0V + DGND +5 V + OVER C3 + DOUT + + BCK C4 + + LRCK + C5 + VINR6 C17 C16 C15 C14 C13 C12 C11 C10 1 2 3 4 5 6 7 8 + + + + + + C9 C8 C7 C6 C19 C18 C2 + 3.3 V (1) PCM1850 (PCM1851) Audio Data Processor NOTE: C1, C2: 0.1-µF ceramic and 10-µF electrolytic capacitors are recommended, depending on layout and power supply. C3, C4, C5: 0.1-µF ceramic and 10-µF electrolytic capacitors are recommended. C6 – C17: A 0.33-µF capacitor gives a 2.9-Hz (τ = 0.33 µF × 169 kΩ) typical cutoff frequency at the HPF input in normal operation, and it requires power-on settling time with a 56-ms time constant in the power-on initialization period. Cutoff frequency and time constant depend on PGA gain. Cutoff frequency varies from 2.4 Hz to 8.5 Hz for 0.33 µF. Dc-coupled input is inhibited for the analog input, VINL[1:6] and VINR[1:6]. C18–C19: A 2.2-µF capacitor with a 10-kΩ load gives a 7.2-Hz cutoff frequency. 27 PCM1850 PCM1851 www.ti.com SLES108 − MARCH 2004 BOARD DESIGN AND LAYOUT CONSIDERATIONS VCC, VDD Pins The digital and analog power supply lines to the PCM1850/1851 must be bypassed to the corresponding ground pins with 0.1-µF ceramic and 10-µF electrolytic capacitors as close to the pins as possible to maximize the dynamic performance of the ADC. AGND, DGND Pins To maximize the dynamic performance of the PCM1850/1851, the analog and digital grounds are not connected internally. These grounds must have low impedance to avoid digital noise feeding back into the analog ground. Therefore, they should be connected directly to each other under the parts to reduce the potential of a noise problem. VINL[1:6], VINR[1:6] Pins A 0.33-µF capacitor is recommended as the ac-coupling capacitor, which gives a 2.4- to 8.5-Hz cutoff frequency. If higher full-scale input voltage is required, it can be adjusted by adding only one series resistor to each VINxx pin, but a signal source resistance less than 1 kΩ is recommended for these pins in order to keep accuracy of the gain control command and to maintain crosstalk performance. MOUTL, MOUTR Pins An ac-coupled light load is recommended; a 2.2-µF capacitor with a 10-kΩ load gives a 7.2-Hz cutoff frequency. VREF1, VREF2, VREFS Pins Between VREF1 and AGND, VREF2 and AGND, and VREFS and AGND, 0.1-µF ceramic and 10-µF electrolytic capacitors are recommended to ensure low source impedance of the ADC references. These capacitors should be located as close as possible to the VREF1, VREF2, and VREFS pins to reduce dynamic errors on the ADC references. The differential voltage between VREF2 and AGND sets the analog input full-scale range. BCK and LRCK Pins (in Master Mode), DOUT Pin These pins have enough load driving capability. However, if the output line is long, locating a buffer near the PCM1850/1851 and minimizing load capacitance is recommended in order to minimize the digital-analog crosstalk and maximize the dynamic performance of the ADC. System Clock Because the PCM1850/1851 operates based on a system clock, the quality of the system clock can influence dynamic performance. Therefore, it is recommended to consider the system clock duty, jitter, and the time difference between the system clock transition and the BCK or LRCK transition in slave mode. 28 MECHANICAL DATA MPQF112 – NOVEMBER 2001 PJT (S-PQFP–N32) PLASTIC QUAD FLATPACK 0,45 0,30 0,80 0,20 M 0,20 0,09 Gage Plane 32 0,15 0,05 1 0,25 0°– 7° 7,00 SQ 0,75 0,45 9,00 SQ 1,05 0,95 Seating Plane 0,10 1,20 1,00 4203540/A 11/01 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. C. 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