PCM1780, PCM1781, PCM1782 SLES132A – MARCH 2005 – REVISED APRIL 2005 24-Bit, 192-kHz Sampling, Enhanced Multilevel, Delta-Sigma, Audio Digital-to-Analog Converter FEATURES APPLICATIONS • • • • • • • • • • • • • • • • • 24-Bit Resolution Analog Performance (VCC = 5 V): – Dynamic Range: 106 dB – SNR: 106 dB, Typical – THD+N: 0.002%, Typical – Full-Scale Output: 3.9 Vp-p, Typical 4×/8× Oversampling Digital Filter: – Stop-Band Attenuation: –50 dB – Pass-Band Ripple: ±0.04 dB Sampling Frequency: 5 kHz to 200 kHz System Clock: 128 fS, 192 fS, 256 fS, 384 fS, 512 fS, 768 fS, 1152 fS With Autodetect Software Control (PCM1780, PCM1782): – Accepts 16-, 18-, 20-, and 24-Bit Audio Data – Formats: Right-Justified, I2S, and Left-Justified – Digital Attenuation: Mode Selectable • 0 dB to –63 dB, 0.5 dB/step • 0 dB to –100 dB, 1 dB/step – Digital De-Emphasis – Digital Filter Rolloff: Sharp or Slow – Soft Mute – Zero Flags for Each Output – Open-Drain Output Zero Flag (PCM1782) Hardware Control (PCM1781): – I2S and 16-Bit Word, Right-Justified – Digital De-Emphasis – Soft Mute – Zero Flag for L-, R-Channel Common Output Power Supply: 5-V Single Supply Small, 16-Lead SSOP Package (150 mil) Pin-Compatible with PCM1680 A/V Receivers DVD Movie Players DVD Add-On Cards For High-End PCs DVD Audio Players HDTV Receivers Car Audio Systems Other Applications Requiring 24-Bit Audio DESCRIPTION The PCM1780/81/82 is a CMOS, monolithic, integrated circuit, which includes stereo digital-to-analog converters and support circuitry in a small 16-lead SSOP package. The data converters use TI’s enhanced multilevel delta-sigma architecture to achieve excellent dynamic performance and improved tolerance to clock jitter. The PCM1780/81/82 accepts industry standard audio data formats with 16- to 24-bit data, providing easy interfacing to audio DSP and decoder chips. Sampling rates up to 200 kHz are supported. The PCM1780/82 provides a full set of user-programmable functions through a three-wire serial control port, which supports register write functions. The PCM1781 provides a subset of user-programmable functions through four control pins. The PCM1780 is pin-compatible with the PCM1680 (8-channel DAC). 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. System Two, Audio Precision are trademarks of Audio Precision, Inc. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2005, Texas Instruments Incorporated PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 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. ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) PCM1780, PCM1781, PCM1782 Supply voltage VCC –0.3 V to 6.5 V Input voltage –0.3 V to VCC + 0.3 V, < 6.5 V Input current (any pins except supplies) ±10 mA 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) (1) 260°C 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. RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range Digital and analog supply voltage, VCC MIN NOM MAX 4.5 5 5.5 Digital input logic family Digital input clock frequency UNIT V TTL System clock Sampling clock Analog output load resistance 8.192 36.864 MHz 32 192 kHz 5 kΩ Analog output load capacitance Digital output load capacitance Operating free-air temperature, TA –25 50 pF 20 pF 85 °C ELECTRICAL CHARACTERISTICS All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data (unless otherwise noted) PARAMETER TEST CONDITIONS MIN Resolution TYP MAX 24 UNIT Bits DATA FORMAT Audio data interface format Audio data bit length Audio data format fS Sampling frequency System clock frequency 2 PCM1780, PCM1782 Right-justified, I2S, left-justified PCM1781 I2S, right-justified PCM1780, PCM1782 16-, 18-, 20-, 24-bit selectable PCM1781 16–24-bit I2S, 16-bit right-justified MSB-first, 2s complement 5 200 128 fS, 192 fS, 256 fS, 384 fS, 512 fS, 768 fS, 1152 fS kHz PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 ELECTRICAL CHARACTERISTICS (continued) All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT DIGITAL INPUT/OUTPUT Logic family VIH 2 Input logic level VIL IIH (1) IIL TTL compatible VIN = VCC (1) IIH (2) 0.8 Input logic current VIN = 0 V IOH = –1 mA Output logic level –10 VIN = VCC VOH (3) VOL (4) 10 VIN = 0 V IIL (2) Vdc 65 100 µA –10 2.4 IOL = 1 mA 0.4 Vdc DYNAMIC PERFORMANCE (5) THD+N Total harmonic distortion + noise VOUT = 0 dB, fS = 48 kHz 0.002% VOUT = 0 dB, fS = 96 kHz, system clock = 256 fS 0.003% VOUT = 0 dB, fS = 192 kHz, system clock = 128 fS 0.004% EIAJ, A-weighted, fS = 48 kHz Dynamic range Signal-to-noise ratio 104 A-weighted, fS = 192 kHz, system clock = 128 fS 102 100 104 A-weighted, fS = 192 kHz, system clock = 128 fS 102 97 dB 106 A-weighted, fS = 96 kHz, system clock = 256 fS fS = 48 kHz Channel separation 106 A-weighted, fS = 96 kHz, system clock = 256 fS EIAJ, A-weighted, fS = 48 kHz SNR 100 0.006% dB 103 fS = 96 kHz, system clock = 256 fS 101 fS = 192 kHz, system clock = 128 fS 100 dB DC ACCURACY Gain error ±1 ±6 % of FSR Gain mismatch, channel-to-channel ±1 ±6 % of FSR ±30 ±80 mV Bipolar zero error V OUT = 49% of VCC at BPZ input ANALOG OUTPUT Output voltage Full scale (–0 dB) Bipolar zero voltage Load impedance AC-coupled load 0.78 VCC Vp-p 0.49 VCC Vdc 5 kΩ DIGITAL FILTER PERFORMANCE Filter Characteristics (Sharp Rolloff) Pass band ±0.04 dB Stop band 0.454 fS 0.546 fS Pass-band ripple Stop-band attenuation (1) (2) (3) (4) (5) 0.04 Stop band = 0.546 fS –50 dB dB Pins 5, 6, 7, 8: SCK, DATA, BCK, LRCK Pins 2, 3, 4: MS, MC, MD (PCM1780/PCM1782). Pins 1, 2, 3, 4: FMT, DEMP0, DEMP1, MUTE (PCM1781) Pins 1, 16: ZEROL, ZEROR (PCM1780). Pin 16: ZEROA (PCM1781) Pins 1, 16: ZEROL, ZEROR (PCM1780/PCM1782). Pin 16: ZEROA (PCM1781) Analog performance specifications are measured using the System Two™ Cascade audio measurement system by Audio Precision™. 3 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 ELECTRICAL CHARACTERISTICS (continued) All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Filter Characteristics (Slow Rolloff, PCM1780/PCM1782) Pass band ±0.5 dB 0.198 fS Stop band 0.884 fS Pass-band ripple ±0.5 Stop-band attenuation Stop band = 0.884 fS dB –35 dB Delay time 20/fS s De-emphasis error ±0.1 dB ANALOG FILTER PERFORMANCE Frequency response at 20 kHz –0.02 at 44 kHz –0.07 dB POWER SUPPLY REQUIREMENTS VCC Voltage range ICC Supply current 4.5 Power dissipation 5 5.5 fS = 48 kHz 25 40 fS = 96 kHz, system clock = 256 fS 30 fS = 192 kHz, system clock = 128 fS 30 fS = 48 kHz 125 fS = 96 kHz, system clock = 256 fS 150 fS = 192 kHz, system clock = 128 fS 150 Vdc mA 200 mW TEMPERATURE RANGE TA Operation temperature θJA Thermal resistance –25 85 115 °C °C/W DEVICE INFORMATION PIN ASSIGNMENTS PCM1780/PCM1782 (TOP VIEW) PCM1781 (TOP VIEW) ZEROL/NA 1 16 ZEROR/ZEROA FMT 1 16 ZEROA MS 2 15 VOUTL DEMP0 2 15 VOUTL MC 3 14 VOUTR DEMP1 3 14 VOUTR MD 4 13 VCOM MUTE 4 13 VCOM SCK 5 12 AGND SCK 5 12 AGND DATA 6 11 VCC DATA 6 11 VCC BCK 7 10 NC BCK 7 10 NC LRCK 8 9 NC LRCK 8 9 TEST P0014-01 4 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 DEVICE INFORMATION (continued) TERMINAL FUNCTIONS—PCM1780/PCM1782 TERMINAL I/O DESCRIPTION NAME NO. AGND 12 – Ground BCK 7 I Audio data bit clock input (1) DATA 6 I Audio data digital input (1) LRCK 8 I Audio data left and right clock input (1) MC 3 I Mode control clock input (1) (2) MD 4 I Mode control data input MS 2 I Mode control select input (1) (2) NC (1) (2) 9, 10 – No connection SCK 5 I System clock input (1) VCC 11 – Power supply, 5-V VCOM 13 – Common voltage decoupling VOUTL 15 O Analog output for L-channel VOUTR 14 O Analog output for R-channel ZEROL/NA 1 O Zero flag output for L-channel / No assign (3) ZEROR/ZEROA 16 O Zero flag output for R-channel / Zero flag output for L- and R-channels(3) (1) (2) (3) Schmitt-trigger input Pulldown Open-drain output (PCM1782) TERMINAL FUNCTIONS—PCM1781 TERMINAL I/O DESCRIPTION NAME NO. AGND 12 – Ground BCK 7 I Audio data bit clock input (1) DATA 6 I Audio data digital input (1) DEMP0 2 I De-emphasis control (1) (2) DEMP1 3 I De-emphasis control (1) (2) FMT 1 I Data format select (1) (2) LRCK 8 I Audio data left and right clock input (1) MUTE 4 I Soft mute control (1) (2) NC 10 – No connection SCK 5 I System clock input (1) TEST 9 – Test pin for factory use. Must be LOW or open (1) (2) VCC 11 – Power supply, 5-V VCOM 13 – Common voltage decoupling VOUTL 15 O Analog output for L-channel VOUTR 14 O Analog output for R-channel ZEROA 16 O Zero flag output for L- and R-channels (1) (2) Schmitt-trigger input Pulldown 5 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 Functional Block Diagram BCK Audio Serial Port LRCK DATA (FMT) MS (DEMP0) MC (DEMP1) Serial Control Port DAC 4/8 Oversampling Digital Filter With Function Control Enhanced Multilevel Delta-Sigma Modulator MD (MUTE) Output Amp and Low-Pass Filter VOUTR System Clock Zero Detect AGND Power Supply VCC ZEROR/ZEROA(1) (ZEROA) System Clock Manager ZEROL/NA(1) SCK VOUTL VCOM DAC (TEST) Output Amp and Low-Pass Filter B0030-01 (1) Open-drain output for the PCM1782 NOTE: Signal names in parentheses ( ) are for the PCM1781. 6 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 TYPICAL PERFORMANCE CURVES All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise noted Digital Filter (De-Emphasis Off) FREQUENCY RESPONSE (SHARP ROLLOFF) PASS-BAND FREQUENCY RESPONSE (SHARP ROLLOFF) 0.05 0 0.04 −20 0.03 0.02 Amplitude – dB Amplitude – dB −40 −60 −80 0.01 0.00 −0.01 −0.02 −100 −0.03 −120 −0.04 −0.05 0.0 −140 0 1 2 3 4 Frequency [× fS] 0.1 0.2 0.3 0.4 Frequency [× fS] G001 G002 Figure 1. Figure 2. FREQUENCY RESPONSE (SLOW ROLLOFF) TRANSITION CHARACTERISTICS (SLOW ROLLOFF) 0 0.5 5 4 −20 3 2 Amplitude – dB Amplitude – dB −40 −60 −80 1 0 −1 −2 −100 −3 −120 −4 −140 0 1 2 Frequency [× fS] Figure 3. 3 −5 0.0 4 G003 0.1 0.2 0.3 Frequency [× fS] 0.4 0.5 G004 Figure 4. 7 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 TYPICAL PERFORMANCE CURVES (Continued) All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise noted De-Emphasis Filter DE-EMPHASIS DE-EMPHASIS ERROR 0.5 0 fS = 32 kHz −1 0.3 De-Emphasis Error – dB −2 De-Emphasis Level – dB fS = 32 kHz 0.4 −3 −4 −5 −6 −7 0.2 0.1 0.0 −0.1 −0.2 −8 −0.3 −9 −0.4 −0.5 −10 0 2 4 6 8 10 12 0 14 2 4 6 8 10 12 G006 G005 Figure 5. Figure 6. DE-EMPHASIS DE-EMPHASIS ERROR 0.5 0 fS = 44.1 kHz −1 0.3 De-Emphasis Error – dB De-Emphasis Level – dB fS = 44.1 kHz 0.4 −2 −3 −4 −5 −6 −7 0.2 0.1 0.0 −0.1 −0.2 −8 −0.3 −9 −0.4 −0.5 −10 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 16 18 20 G008 G007 Figure 7. 14 f – Frequency – kHz f – Frequency – kHz 8 14 f – Frequency – kHz f – Frequency – kHz Figure 8. PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 TYPICAL PERFORMANCE CURVES (Continued) All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise noted DE-EMPHASIS DE-EMPHASIS ERROR 0.5 0 fS = 48 kHz −1 0.3 De-Emphasis Error – dB −2 De-Emphasis Level – dB fS = 48 kHz 0.4 −3 −4 −5 −6 −7 0.2 0.1 0.0 −0.1 −0.2 −8 −0.3 −9 −0.4 −0.5 −10 0 2 4 6 8 10 12 14 16 18 20 0 22 2 4 6 8 10 12 14 16 18 20 22 f – Frequency – kHz f – Frequency – kHz G010 G009 Figure 9. Figure 10. Analog Filter ANALOG FILTER PERFORMANCE 10 0 Amplitude − dB −10 −20 −30 −40 −50 −60 −70 1 10 100 1k 10k f − Frequency − Hz G011 Figure 11. 9 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 TYPICAL PERFORMANCE CURVES (Continued) All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise noted Analog Dynamic Performance Supply Voltage Characteristics THD+N vs SUPPLY VOLTAGE DYNAMIC RANGE vs SUPPLY VOLTAGE 0.01 THD+N − Total Harmonic Distortion + Noise − % 110 Dynamic Range – dB 108 4.75 5.00 5.25 VCC − Supply Voltage − V 102 100 96 4.50 5.50 5.00 5.25 G012 Figure 12. Figure 13. SIGNAL-TO-NOISE RATIO vs SUPPLY VOLTAGE CHANNEL SEPARATION vs SUPPLY VOLTAGE 110 110 108 108 106 104 102 100 98 96 4.50 4.75 VCC – Supply Voltage – V Channel Separation – dB SNR − Signal-to-Noise Ratio – dB 104 98 0.001 4.50 5.50 G013 106 104 102 100 98 4.75 5.00 5.25 VCC – Supply Voltage – V Figure 14. 10 106 5.50 G014 96 4.50 4.75 5.00 5.25 VCC – Supply Voltage – V Figure 15. 5.50 G015 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 TYPICAL PERFORMANCE CURVES (Continued) All specifications at TA = 25°C, VCC = 5 V, fS = 48 kHz, system clock = 512 fS, and 24-bit data, unless otherwise noted Temperature Characteristics THD+N vs TEMPERATURE DYNAMIC RANGE vs TEMPERATURE 0.01 THD+N − Total Harmonic Distortion + Noise − % 110 Dynamic Range – dB 108 104 102 100 98 0.001 −25 0 25 50 96 −25 75 TA − Free-Air Temperature − °C 25 50 Figure 16. Figure 17. SIGNAL-TO-NOISE RATIO vs TEMPERATURE CHANNEL SEPARATION vs TEMPERATURE 110 110 108 108 106 104 102 100 98 96 −25 0 75 TA − Free-Air Temperature − °C G016 Channel Separation – dB SNR − Signal-to-Noise Ratio – dB 106 G017 106 104 102 100 98 0 25 50 TA − Free-Air Temperature − °C Figure 18. 96 −25 75 G018 0 25 50 TA − Free-Air Temperature − °C 75 G019 Figure 19. 11 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 SYSTEM CLOCK AND RESET FUNCTIONS System Clock Input The PCM1780/81/82 requires a system clock for operating the digital interpolation filters and multilevel delta-sigma modulators. The system clock is applied at the SCK input (pin 5). Table 1 shows examples of system clock frequencies for common audio sampling rates. Figure 20 shows the timing requirements for the system clock input. For optimal performance, it is important to use a clock source with low phase jitter and noise. TI’s PLL170x family of multiclock generators is an excellent choice for providing the PCM1780/81/82 system clock. Table 1. System Clock Frequencies for Common Audio Sampling Frequencies SAMPLING FREQUENCY 192 fS 256 fS 384 fS 512 fS 8 kHz 1.024 1.536 2.048 3.072 4.096 6.144 9.216 16 kHz 2.048 3.072 4.096 6.144 8.192 12.288 18.432 768 fS 1152 fS 32 kHz 4.096 6.144 8.192 12.288 16.384 24.576 36.864 44.1 kHz 5.6448 8.4672 11.2896 16.9344 22.5792 33.8688 – (1) 48 kHz 6.144 9.216 12.288 18.432 24.576 36.864 – (1) – (1) – (1) 88.2 kHz 11.2896 16.9344 22.5792 33.8688 – (1) 96 kHz 12.288 18.432 24.576 36.864 – (1) – (1) – (1) 36.864 – (1) – (1) – (1) – (1) – (1) 192 kHz (1) SYSTEM CLOCK FREQUENCY (fSCK), MHz 128 fS 24.576 This system clock frequency is not supported for the given sampling frequency. t(SCKH) H 2V System Clock 0.8 V L t(SCKL) System Clock Pulse Cycle Time(1) T0005-08 (1) 1/128 fS, 1/256 fS, 1/384 fS, 1/512 fS, 1/768 fS, or 1/1152 fS PARAMETER MIN TYP MAX UNIT t(SCKH) System clock pulse duration, HIGH 7 ns t(SCKL) System clock pulse duration, LOW 7 ns Figure 20. System Clock Input Timing 12 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 Power-On-Reset Functions The PCM1780/81/82 includes a power-on-reset function. Figure 21 shows the operation of this function. With the system clock active and VCC > 3 V (typical, 2.2 V to 3.7 V), the power-on-reset function is enabled. The initialization sequence requires 3072 system clocks from the time VCC > 3 V (typical, 2.2 V to 3.7 V). After the initialization period, the PCM1780/82 is set to its reset default state, as described in the Mode Control Register section of this data sheet. During the reset period (3072 system clocks), the analog output is forced to the common voltage (VCOM), or VCC/2. After the reset period, the internal register is initialized in the next 1/fS period and if SCK, BCK, and LRCK are provided continuously, the PCM1780/81/82 provides the proper analog output with a group delay corresponding to the input data. VCC 3.7 V 3V 2.2 V 0V Reset Reset Release Internal Reset Don’t Care 3072 System Clocks System Clock T0014-06 Figure 21. Power-On-Reset Timing Audio Serial Interface The audio serial interface for the PCM1780/81/82 consists of a three-wire synchronous serial port. It includes LRCK (pin 8), BCK (pin 7), and DATA (pin 6). BCK is the serial audio bit clock, and it is used to clock the serial data present on DATA into the serial shift register of the audio interface. Serial data is clocked into the PCM1780/81/82 on the rising edge of BCK. LRCK is the serial audio left/right word clock. It is used to latch serial data into the internal registers of the serial audio interface. Both LRCK and BCK should be synchronous with the system clock. Ideally, it is recommended that LRCK and BCK be derived from the system clock input, SCK. LRCK is operated at the sampling frequency, fS. BCK can be operated at 32, 48, or 64 times the sampling frequency. Internal operation of the PCM1780/81/82 is synchronized with LRCK. Accordingly, internal operation of the device is suspended when the sampling rate clock, LRCK, is changed or SCK and/or BCK is interrupted at least for three bit-clock cycles. If SCK, BCK, and LRCK are provided continuously after this suspended condition, the internal operation is resynchronized automatically within a period of less than 3/fS. External resetting is not required. Audio Data Formats and Timing The PCM1780/82 supports industry-standard audio data formats, including right-justified, I2S, and left-justified. The PCM1781 supports I2S and 16-bit-word, right-justified. The data formats are shown in Figure 22. Data formats are selected for the PCM1780/82 using the format bits, FMT[2:0], located in control register 20, and are selected for the PCM1781 using the FMT pin. The default data format is 24-bit, left-justified. All formats require binary 2s complement, MSB-first audio data. Figure 23 shows a detailed timing diagram for the serial audio interface. 13 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 (1) Right-Justified Data Format; L-Channel = HIGH, R-Channel = LOW 1/fS LRCK L-Channel R-Channel BCK (= 32 fS, 48 fS, or 64 fS) 16-Bit Right-Justified, BCK = 32 fS DATA 14 15 16 1 2 3 14 15 16 1 LSB MSB 2 3 14 15 16 MSB LSB 16-Bit Right-Justified, BCK = 48 fS or 64 fS DATA 14 15 16 1 2 3 14 15 16 MSB 1 2 3 14 15 16 MSB LSB LSB 18-Bit Right-Justified, BCK = 48 fS or 64 fS DATA 16 17 18 1 2 3 16 17 18 MSB 1 LSB 2 3 16 17 18 MSB LSB 20-Bit Right-Justified, BCK = 48 fS or 64 fS DATA 18 19 20 1 2 3 18 19 20 MSB 1 LSB 2 3 18 19 20 MSB LSB 24-Bit Right-Justified, BCK = 48 fS or 64 fS DATA 22 23 24 1 2 3 22 23 24 MSB 1 2 LSB 3 22 23 24 MSB LSB (2) I2S Data Format; L-Channel = LOW, R-Channel = HIGH 1/fS LRCK L-Channel R-Channel BCK (= 32 fS, 48 fS or 64 fS) DATA 1 2 3 N–2 N–1 MSB LSB N 1 2 3 N–2 MSB N–1 N 1 2 LSB (3) Left-Justified Data Format; L-Channel = HIGH, R-Channel = LOW 1/fS LRCK L-Channel R-Channel BCK (= 32 fS, 48 fS, or 64 fS) DATA 1 2 3 N–2 N–1 MSB LSB N 1 2 3 MSB N–2 N–1 N 1 2 LSB T0009-02 Figure 22. Audio Data Input Formats 14 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 LRCK t(BCL) t(BCH) t(LS) BCK t(BCY) t(LH) DATA t(DS) t(DH) PARAMETER T0010-03 MIN UNIT )(1) t(BCY) BCK pulse cycle time t(BCH) BCK pulse duration, HIGH 35 ns t(BCL) BCK pulse duration, LOW 35 ns t(LS) LRCK setup time to BCK rising edge 10 ns t(LH) LRCK hold time to BCK rising edge 10 ns t(DS) DATA setup time 10 ns t(DH) DATA hold time 10 ns (1) 1/(32 fS), 1/(48 fS), 1/(64 fS fS is the sampling frequency (e.g., 44.1 kHz, 48 kHz, 96 kHz, etc.). Figure 23. Audio Interface Timing 15 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 OVERSAMPLING RATE CONTROL The PCM1780/81/82 automatically controls the oversampling rate of the delta-sigma D/A converters with the system clock frequency. The oversampling rate is set to 64× oversampling with an 1152-fS, 768-fS, or 512-fS system clock, to 32× oversampling with a 384-fS or 256-fS system clock, or to 16× oversampling with a 192-fS or 128-fS system clock. ZERO FLAGS (PCM1780/82) Zero-Detect Condition Zero detection for each output channel is independent from the other. If the data for a given channel remains at a 0 level for 1024 sample periods (or LRCK clock periods), a zero-detect condition exists for that channel. Zero-Flag Outputs Each channel has a corresponding zero-flag pin, ZEROL (pin 1) or ZEROR (pin 16). Given that a zero-detect condition exists for one or more channels, the zero-flag pins for those channels are set to a logic-1 state. The zero-flag pins can be used to operate external mute circuits, or used as status indicators for a microcontroller, audio signal processor, or other digitally controlled function. The active polarity of the zero-flag outputs can be inverted by setting the ZREV bit of control register 22 to 1. The reset default is active-high output, or ZREV = 0. The L-channel and R-channel common zero flag can be selected by setting the AZRO bit of control register 22 to 1. The reset default is for independent L-channel and R-channel zero flags, or AZRO = 0. On the PCM1782, ZEROL and ZEROR are open-drain outputs. ZERO FLAG (PCM1781) The PCM1781 has a zero-flag pin, ZEROA (pin 16). ZEROA is the L-channel and R-channel common zero-flag pin. If the data for L-channel and R-channel remains at a 0 level for 1024 sampling periods (or LRCK clock periods), ZEROA is set to a logic-1 state. HARDWARE CONTROL (PCM1781) The digital functions of the PCM1781 are capable of hardware control. Table 2 shows selectable formats, Table 3 shows de-emphasis control, and Table 4 shows muting control. Table 2. Data Format Selection FMT (PIN 1) DATA FORMAT LOW 16- to 24-bit, I2S format HIGH 16-bit right-justified Table 3. De-Emphasis Control DEMP1 (PIN 3) DEMP0 (PIN 2) DE-EMPHASIS FUNCTION LOW LOW OFF LOW HIGH 48-kHz de-emphasis ON HIGH LOW 44.1-kHz de-emphasis ON HIGH HIGH 32-kHz de-emphasis ON Table 4. Mute Control 16 MUTE (PIN 4) MUTE STATUS LOW Mute OFF HIGH Mute ON PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 SOFTWARE CONTROL (PCM1780/82) The PCM1780/82 has many programmable functions that can be controlled in the software control mode; the functions are controlled by programming the internal registers using MS, MC, and MD. The serial control interface is a 3-wire serial port which operates asynchronously to the audio serial interface. The serial control interface is used to program the on-chip mode registers. The control interface includes MD (pin 4), MC (pin 3), and MS (pin 2). MD is the serial data input, used to program the mode registers. MC is the serial bit clock, used to shift data into the control port. MS is the select input, used to enable the mode control port. Register Write Operation All write operations for the serial control port use 16-bit data words. Figure 24 shows the control data word format. The most significant bit must be a 0. Seven bits, labeled IDX[6:0], set the register index (or address) for the write operation. The least significant eight bits, D[7:0], contain the data to be written to the register specified by IDX[6:0]. Figure 25 shows the functional timing diagram for writing to the serial control port. MS 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, corresponding to the 16 bits of the control data word on MD. After the sixteenth clock cycle has completed, MS is set to logic 1 to latch the data into the indexed mode control register. LSB MSB 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7 D6 D5 Register Index (or Address) D4 D3 D2 D1 D0 Register Data R0001-01 Figure 24. Control Data Word Format for MD MS MC MD X 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 D7 D6 D5 D4 D3 D2 D1 D0 X X 0 IDX6 T0048-01 Figure 25. Register Write Operation Control Interface Timing Requirements Figure 26 shows a detailed timing diagram for the serial control interface. These timing parameters are critical for proper control port operation. 17 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 t(MHH) MS t(MSS) t(MCL) t(MCH) t(MSH) MC t(MCY) LSB MD t(MDS) t(MDH) T0013-03 PARAMETER MIN UNIT t(MCY) MC pulse cycle time 100 ns t(MCL) MC low-level time 50 ns t(MCH) MC high-level time 50 ns )(2) t(MHH) MS high-level time t(MSS) MS falling edge to MC rising edge 3/(256 × fS 20 ns t(MSH) MS hold time(1) 20 ns t(MDH) MD hold time 15 ns t(MDS) MD setup time 20 ns (1) MC rising edge for LSB to MS rising edge (2) fS: sampling rate Figure 26. Control Interface Timing 18 ns PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 MODE CONTROL REGISTERS (PCM1780/82) User-Programmable Mode Controls The PCM1780/82 includes a number of user-programmable functions, which are accessed via control registers. The registers are programmed using the serial control interface, which was previously discussed in the Software Control section of this data sheet. Table 5 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 6. Each register includes an index (or address) indicated by the IDX[6:0] bits. Table 5. User-Programmable Mode Controls FUNCTION RESET DEFAULT REGISTER BIT(S) Digital attenuation control, 0 dB to –63 dB in 0.5-dB steps 0 dB, no attenuation 16 and 17 AT1[7:0], AT2[7:0] Soft mute control Mute disabled 18 MUT[2:0] Oversampling rate control ×64, ×32, ×16 18 OVER Soft reset control Reset disabled 18 SRST DAC operation control DAC1 and DAC2 enabled 19 DAC[2:1] De-emphasis function control De-emphasis disabled 19 DM12 De-emphasis sample rate selection 44.1 kHz 19 DMF[1:0] Audio data format control 24-bit, left-justified 20 FMT[2:0] Digital filter rolloff control Sharp rolloff 20 FLT Digital attenuation mode select 0 to –63 dB, 0.5 dB/step 21 DAMS Output phase select Normal Phase 22 DREV Zero-flag polarity select High 22 ZREV Zero-flag function select L-, R-channels independent 22 AZRO Table 6. Mode Control Register Map IDX REGIS- B15 (B8–B14) TER B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 AT11 AT10 10h 16 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 AT17 AT16 AT15 AT14 AT13 AT12 11h 17 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 AT27 AT26 AT25 AT24 AT23 AT22 AT21 AT20 12h 18 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 SRST OVER RSV RSV RSV RSV MUT2 MUT1 13h 19 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV RSV DAC2 DAC1 14h 20 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV FLT RSV RSV FMT2 FMT1 FMT0 15h 21 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV RSV RSV RSV RSV DAMS 16h 22 0 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 RSV RSV RSV RSV 0 DMF1 DMF0 DM12 RSV AZRO ZREV DREV 19 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 Register Definitions B15 REGISTER 16 0 B15 REGISTER 17 0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B7 B6 B5 B4 B3 B2 B1 B0 AT17 AT16 AT15 AT14 AT13 AT12 AT11 AT10 B7 B6 B5 B4 B3 B2 B1 B0 AT27 AT26 AT25 AT24 AT23 AT22 AT21 AT20 ATx[7:0]: Digital Attenuation Level Setting Where x = 1 or 2, corresponding to the DAC output VOUTL (x = 1) and VOUTR (x = 2) Default value: 1111 1111b ATx[7:0] DECIMAL VALUE ATTENUATION LEVEL SETTING DAMS = 0 DAMS = 1 1111 1111b 255 0 dB, no attenuation (default) 0 dB, no attenuation (default) 1111 1110b 254 –0.5 dB –1 dB 1111 1101b 253 –1 dB –2 dB : : : : 1001 1100b 156 –49.5 dB –99 dB 1001 1011b 155 –50 dB –100 dB 1001 1010b 154 –50.5 dB Mute : : 1000 0010b 130 –62.5 dB Mute : 1000 0001b 129 –63 dB Mute 1000 0000b 128 Mute Mute : : : : 0000 0000b 0 Mute Mute Each DAC channel (VOUTL or VOUTR) includes a digital attenuation function. The attenuation level can be set from 0 dB to R dB, in S-dB steps. Changes in attenuator levels are made by incrementing or decrementing by one step (S dB) every 8/fS time internal until the programmed attenuator setting is reached. Alternatively, the attenuation level can be set to infinite attenuation (or mute). R (range) and S (step) are –63 and 0.5 for DAMS = 0 and –100 and 1 for DAMS = 1, respectively. The DAMS bit is defined in register 21. The attenuation data for each channel can be set individually. The attenuation level can be calculated using the following formula: Attenuation level (dB) = S • (ATx[7:0]DEC – 255) where ATx[7:0]DEC = 0 through 255. For ATx[7:0]DEC = 0 through 128 with DAMS = 0, or for ATx[7:0]DEC = 0 through 154 with DAMS = 1, the attenuation level is set to infinite attenuation (mute). 20 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 B15 REGISTER 18 0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B7 B6 B5 B4 B3 B2 B1 B0 SRST OVER RSV RSV RSV RSV MUT2 MUT1 NOTE: RSV indicates a reserved bit that should be set to 0. MUTx: Soft Mute Control Where x = 1 or 2, corresponding to the DAC output VOUTL (x = 1) and VOUTR (x = 2). Default value: 0 MUTx = 0 Mute disabled (default) MUTx = 1 Mute enabled The mute bits, MUT1 and MUT2, are used to enable or disable the soft mute function for the corresponding DAC outputs, VOUTL and VOUTR. The soft mute function is incorporated into the digital attenuators. When mute is disabled (MUTx = 0), the attenuator and DAC operate normally. When mute is enabled by setting MUTx = 1, the digital attenuator for the corresponding output is decreased from the current setting to infinite attenuation, one attenuator step (S dB) for every 8/fS seconds. This provides pop-free muting of the DAC output. The step size, S, is 0.5 dB for DAMS = 0 and 1 dB for DAMS = 1. By setting MUTx = 0, the attenuator is increased one step for every 8/fS seconds to the previously programmed attenuation level. OVER: Oversampling Rate Control Default value: 0 System clock frequency = 512 fS, 768 fS, or 1152 fS OVER = 0 ×64 oversampling (default) OVER = 1 ×128 oversampling (applicable only if sampling clock frequency ≤ 24 kHz) System clock frequency = 256 fS or 384 fS OVER = 0 ×32 oversampling (default) OVER = 1 ×64 oversampling (applicable only if sampling clock frequency ≤ 48 kHz) System clock frequency = 128 fS, 192 fS OVER = 0 ×16 oversampling (default) OVER = 1 ×32 oversampling (applicable only if sampling clock frequency ≤ 96 kHz) The OVER bit is used to control the oversampling rate of the delta-sigma D/A converters. Setting OVER = 1 is recommended under the following conditions: • System clock frequency = 512 fS, 768 fS, or 1152 fS, and sampling clock frequency = 24 kHz • System clock frequency = 256 fS or 384 fS and sampling clock frequency = 48 kHz • System clock frequency = 128 fS or 192 fS and sampling clock frequency = 96 kHz SRST: Reset Default value: 0 SRST = 0 Reset disabled (default) SRST = 1 Reset enabled The SRST bit is used to enable or disable the soft reset function. The operation is the same as for the power-on-reset function with the exception of the reset period, which is 1024 system clocks for the SRST function. All registers are initialized. 21 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 B15 REGISTER 19 0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B7 B6 B5 B4 B3 B2 B1 B0 RSV DMF1 DMF0 DM12 RSV RSV DAC2 DAC1 NOTE: RSV indicates a reserved bit that should be set to 0. DACx: DAC Operation Control Where x = 1 or 2, corresponding to the DAC output VOUTL (x = 1) or VOUTR (x = 2). Default value: 0 DACx = 0 DAC operation enabled (default) DACx = 1 DAC operation disabled The DAC operation controls are used to enable and disable the DAC outputs, VOUTL and VOUTR. When DACx = 0, the corresponding output generates the audio waveform dictated by the data present on the DATA pin. When DACx = 1, the corresponding output is set to the dc common voltage (VCOM), equal to VCC/2. DM12: Digital De-Emphasis Function Control Default value: 0 DM12 = 0 De-emphasis disabled (default) DM12 = 1 De-emphasis enabled The DM12 bit is used to enable or disable the digital de-emphasis function. Refer to the plots shown in the Typical Performance Curves section of this data sheet. DMF[1:0]: Sampling Frequency Selection for the De-Emphasis Function Default value: 00 DMF[1:0] De-Emphasis Sample Rate Selection 00 44.1 kHz (default) 01 48 kHz 10 32 kHz 11 Reserved The DMF[1:0] bits are used to select the sampling frequency used for the digital de-emphasis function when it is enabled. 22 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 B15 REGISTER 20 0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B7 B6 B5 B4 B3 B2 B1 B0 RSV RSV FLT RSV RSV FMT2 FMT1 FMT0 NOTE: RSV indicates a reserved bit that should be set to 0. FMT[2:0]: Audio Interface Data Format Default value: 101 FMT[2:0] Audio Data Format Selection 000 24-bit right-justified format, standard data 001 20-bit right-justified format, standard data 010 18-bit right-justified format, standard data 011 16-bit right-justified format, standard data 100 I2S format, 16 to 24 bits 101 Left-justified format, 16 to 24 bits (default) 110 Reserved 111 Reserved The FMT[2:0] bits are used to select the data format for the serial audio interface. The preceding table shows the available format options. FLT: Digital Filter Rolloff Control Default value: 0 FLT = 0 Sharp rolloff (default) FLT = 1 Slow rolloff The FLT bit allows users to select the digital filter rolloff that is best suited to their application. Two filter rolloff selections are available: sharp and slow. The filter responses for these selections are shown in the Typical Performance Curves section of this data sheet B15 REGISTER 21 0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B7 B6 B5 B4 B3 B2 B1 B0 RSV RSV RSV RSV RSV RSV RSV DAMS NOTE: RSV indicates a reserved bit that should be set to 0. DAMS: Digital Attenuation Mode Select Default value: 0 DAMS = 0 Fine step, 0.5 dB/step for 0 to –63 dB range (default) DAMS = 1 Wide range, 1 dB/step for 0 to –100 dB range The DAMS bit is used to select the digital attenuation mode. 23 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 B15 REGISTER 22 0 B14 B13 B12 B11 B10 B9 B8 IDX6 IDX5 IDX4 IDX3 IDX2 IDX1 IDX0 B7 B6 B5 B4 B3 B2 B1 B0 RSV RSV RSV RSV 0 AZRO ZREV DREV NOTE: RSV indicates a reserved bit that should be set to 0. DREV: Output Phase Select Default value: 0 DREV = 0 Normal output (default) DREV = 1 Inverted output The DREV bit allows the user to control the phase of the analog output signal. ZREV: Zero-Flag Polarity Select Default value: 0 ZREV = 0 Zero-flag pins HIGH at a zero detect (default) ZREV = 1 Zero-flag pins LOW at a zero detect The ZREV bit allows the user to select the polarity of the zero-flag pins. AZRO: Zero Flag Function Select Default value: 0 AZRO = 0 Pin 1: ZEROL; zero-flag output for L-channel Pin 16: ZEROR; zero-flag output for R-channel AZRO = 1 Pin 1: NA; not assigned Pin 16: ZEROA; zero-flag output for L-/R-channel The AZRO bit allows the user to select the function of zero-flag pins. 24 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 ANALOG OUTPUTS The PCM1780/81/82 includes two independent output channels, VOUTL and VOUTR. These are unbalanced outputs, each capable of driving 3.9 Vp-p typical into a 5-kΩ ac-coupled load. The internal output amplifiers for VOUTL and VOUTR are biased to the dc common voltage, equal to 0.5 VCC. The output amplifiers include an RC continuous-time filter, which helps to reduce the out-of-band noise energy present at the DAC outputs due to the noise-shaping characteristics of the PCM1780/81/82 delta-sigma D/A converters. The frequency response of this filter is shown as ANALOG FILTER in the Typical Performance Curves section. By itself, this filter is not enough to attenuate the out-of-band noise to an acceptable level for many applications. An external low-pass filter is required to provide sufficient out-of-band noise rejection. Further discussion of DAC post-filter circuits is provided in the Application Information section of this data sheet. VCOM Output One unbuffered common voltage output pin, VCOM (pin 13), is brought out for decoupling purposes. This pin is nominally biased to the dc common voltage, equal to VCC/2. This pin can be used to bias external circuits. Figure 27 shows an example of using the VCOM pin for external biasing applications. AV 1, where A V PCM1780/81/82 R3 2 VOUTX† 3 C2 – 1/2 OPA2353 1 R4 + R1 VCC C1 R2 R2 R1 + R5 VCOM + † 10 µF X = L or R (a) Using VCOM to Bias a Single-Supply Filter Stage VCC PCM1780/81/82 – OPA337 Buffered VCOM + VCOM + 10 µF (b) Using a Voltage Follower to Buffer VCOM When Biasing Multiple Nodes S0054-01 Figure 27. Biasing External Circuits Using the VCOM Pin 25 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 APPLICATION INFORMATION Connection Diagrams A basic connection diagram is shown in Figure 28, with the necessary power supply bypassing and decoupling components. TI recommends using the component values shown in Figure 28 for all designs. The use of series resistors (22 Ω to 100 Ω) is recommended for the SCK, LRCK, BCK, and DATA inputs. The series resistor combines with the stray PCB and device input capacitance to form a low-pass filter which reduces high-frequency noise emissions and helps to dampen glitches and ringing present on clock and data lines. System Clock 16 MS VOUTL 15 + ZEROL/NA 2 3 MC VOUTR 14 4 MD 5 SCK R1 PCM1780 PCM1782 VCOM 13 AGND 12 R2 PCM Audio Data 6 DATA VCC 11 7 BCK NC 10 8 LRCK NC 9 1 FMT 2 3 C4 Post LPF L-Ch OUT Post LPF R-Ch OUT C3 + 1 C2 0V C1 + Mode Control ZEROR/ZEROA + Zero Mute Control 5V R3 R4 ZEROA 16 DEMP0 VOUTL 15 + DEMP1 VOUTR 14 Mute System Clock 4 MUTE PCM1781 R1 5 SCK VCOM 13 AGND 12 R2 PCM Audio Data 6 DATA VCC 11 7 BCK NC 10 8 LRCK Post LPF L-Ch OUT Post LPF R-Ch OUT C3 + De-Emphasis C4 C2 0V + Format + Zero Mute Control C1 5V R3 R4 TEST 9 C1: 0.1 µF Ceramic and 10 µF Electrolytic C2: 10 µF Electrolytic C3, C4: 4.7 µF − 10 µF Electrolytic R1 − R4: 22 Ω − 100 Ω S0055-01 Figure 28. Basic Connection Diagram 26 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 APPLICATION INFORMATION (continued) Power Supplies and Grounding The PCM1780/81/82 requires a 5-V supply for VCC. Proper power supply bypassing is shown in Figure 28. The 0.1-µF ceramic capacitor and the 10-µF electrolytic capacitor are recommended. D/A Output Filter Circuits Delta-sigma D/A converters use noise-shaping techniques to improve in-band signal-to-noise ratio (SNR) performance at the expense of generating increased out-of-band noise above the Nyquist frequency, or fS/2. The out-of-band noise must be low-pass filtered in order to provide optimal converter performance. This is accomplished by a combination of on-chip and external low-pass filtering. Figure 27(a) and Figure 29 show the recommended external low-pass active filter circuits for single- and dual-supply applications. These circuits are second-order Butterworth filters using the multiple feedback (MFB) circuit arrangement, which reduces sensitivity to passive component variations over frequency and temperature. For more information regarding MFB active filter design, see Dynamic Performance Testing of Digital Audio D/A Converters (SBAA055), available from the TI Web site at http://www.ti.com. R2 R1 VIN C2 AV C1 R3 2 3 – OPA2134 1 R4 VOUT + R2 R1 S0053-01 Figure 29. Dual-Supply Filter Circuit PCB LAYOUT GUIDELINES A typical PCB floor plan for the PCM1780/81/82 is shown in Figure 30. A ground plane is recommended, with the analog and digital sections being isolated from one another using a split or cut in the circuit board. The PCM1780/81/82 should be oriented with the digital I/O pins facing the ground plane split/cut to allow for short, direct connections to the digital audio interface and control signals originating from the digital section of the board. Separate power supplies are recommended for the digital and analog sections of the board. This prevents the switching noise present on the digital supply from contaminating the analog power supply and degrading the dynamic performance of the PCM1780/81/82. In cases where a common 5-V supply must be used for the analog and digital sections, an inductance (RF choke, ferrite bead) should be placed between the analog and digital 5-V supply connections to avoid coupling of the digital switching noise into the analog circuitry. Figure 31 shows the recommended approach for single-supply applications. 27 PCM1780, PCM1781, PCM1782 www.ti.com SLES132A – MARCH 2005 – REVISED APRIL 2005 APPLICATION INFORMATION (continued) Digital Power +VD Analog Power DGND AGND +5VA +VS –VS VCC Digital Logic and Audio Processor Output Circuits PCM1780/81/82 Digital Ground AGND Digital Section Analog Ground Analog Section Return Path for Digital Signals B0031-01 Figure 30. Recommended PCB Layout Power Supplies RF Choke or Ferrite Bead +5V VDD Digital Logic and Audio Processor AGND +VS –VS VCC PCM1780/81/82 Output Circuits AGND Digital Section Analog Section Common Ground B0032-01 Figure 31. Single-Supply PCB Layout 28 PACKAGE OPTION ADDENDUM www.ti.com 23-Aug-2005 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty PCM1780DBQ ACTIVE SSOP/ QSOP DBQ 16 PCM1780DBQR ACTIVE SSOP/ QSOP DBQ 16 PCM1781DBQ ACTIVE SSOP/ QSOP DBQ 16 PCM1781DBQR ACTIVE SSOP/ QSOP DBQ 16 PCM1782DBQ ACTIVE SSOP/ QSOP DBQ 16 PCM1782DBQR ACTIVE SSOP/ QSOP DBQ 16 98 Lead/Ball Finish MSL Peak Temp (3) Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM 98 98 (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) 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. 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. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. 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