Burr Brown PCM1738 - 24-Bit, 192kHz Sampling.pdf - MaxDat

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B15 B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0REGISTER 21 W/R 0 0 1 0 1 0 1 RSV RSV RSV RSV RSV RSV ZFGR ZFGLW/RZFGxRead/Write Mode ControlOnly available to set 0 for Read back mode.Zero Detection FlagWhen x = L or R, corresponding to the DAC output channel.These bits are Read only.Default Value: 00ZFGx = 0ZFGx = 1Not ZEROZERO DetectedWhen the PCM1738 detects that audio input data is continuously zero for 1024f S , the ZFGx bit is set to 1 forthe corresponding channel(s). Zero detect flags are also available at ZEROL (pin 2) and ZEROR (pin 3).TYPICAL CONNECTION DIAGRAM IN PCM MODEControllerPCM1738E+5.0V +15V –15V1RSTV CC 328+2ZEROLAGND2273ZERORI OUT L–26L/R Clock (f S )Audio DATA45LRCKDATAI OUT L+V CC 22524V OUTL-ChannelBit Clock6BCKV CC 123+System Clock7SCKIV COM 322+8DGNDI REF21+3.3V9V DDV COM 22010SCKOV COM 119+1112MDOMDIAGND1I OUT R+1817V OUTR-Channel13MCI OUT R–1614CSMUTE15Analog Output StageFIGURE 8. Typical Application Circuit for Standard PCM Audio Operation.22PCM1738SBAS174A
ANALOG OUTPUTSPCM1738E+5.0VV CC 3AGND2I OUT L–I OUT L+V CC 2V CC 1V COM 3I REFV COM 2V COM 1AGND1I OUT R+I OUT R–MUTE28272625242322212019181716150.1µF++10µF+10µFR 116kΩ10µF+10µFC 13R 18R 11C 17C 12C 14R 13R 16R14C 15C 23R 28R 21C 27C 22C 24R 23R 26R24C 25C 21V OUTL-ChannelV OUTR-ChannelNOTE: Example R/C values for f C 45kHz.R 11 -R 18 , R 21 -R 28 : 620Ω, C 11 , C 12 , C 21 , C 22 : not populated, C 13 , C 14 ,C 23 , C 24 : 5600pF, C 15 , C 25 : 8200pF, C 16 , C 17 , C 26 , C 27 : 1800pF.OPA627BP, BMor OPA5534 Op AmpOPA134, OPA2134, orOPA604, OPA2604 Op AmpFIGURE 9. Typical Application for Analog Output Stage.ANALOG OUTPUT LEVEL AND I/V CONVERTERThe signal level of the DAC current output pins (I OUT L+,I OUT L–, I OUT R+, and I OUT R–) is ±2.48mA (p-p) at 0dB (FullScale). The voltage output of the I/V converter is given bythe following equation:V OUT = ±2.48mApp • R F (1)Here, R f is the feedback resistor in the I/V (current-tovoltage)conversion circuit, R 11 , R 12 , R 21 , and R 22 on atypical application circuit. The common level of the I/Vconversion circuit must be the same as the common level ofDAC I OUT that is given by the V COM 2 reference voltage,+2.5V DC. The non-inverting inputs of the op amps shownin the I/V circuits are connected to V COM 2 to provide thecommon bias voltage.Op Amp for I/V Converter CircuitThe OPA627BP/BM, or 5534 type op amp, is recommendedfor the I/V conversion circuit to obtain specified audioperformance. Dynamic performance, such as gain bandwidth,settling time, and slew rate of the op amp createsaudio dynamic performance at the I/V section. Input noisespecification of the op amp should be considered to obtain120dB S/N ratio.Analog Gain by Balanced AmplifierThe I/V converters are followed by balanced amplifierstages that sum the differential signals for each channel,creating a single-ended voltage output. In addition, thebalanced amplifiers provide a second-order, low-pass filterfunction that band limits the audio output signal. The cutofffrequency and gain is given by external R and C componentvalues. In the case of Figure 9, the cutoff frequency is 45kHzwith a gain of 1. The output voltage for each channel is 6.2Vp-p, or 2.2Vrms.REFERENCE CURRENT RESISTORAs shown in the analog output application circuit, markedR 1 on Figure 9, there is a resistor connected from I REF (pin21) to the analog ground, designated as R 1 . This resistor setsthe current for the internal reference circuit. The value of R 1must be 16kΩ, ±1% in order to match the specified gainerror shown in the Specifications table.PCM1738 23SBAS174A
Page 2 and 3: SPECIFICATIONSAll specifications at
Page 4 and 5: V CC 1BLOCK DIAGRAMLRCKDATABCKInput
Page 6 and 7: TYPICAL PERFORMANCE CURVES (Cont.)A
Page 8 and 9: TYPICAL PERFORMANCE CURVES (Cont.)A
Page 10 and 11: ANALOG FIR FILTER PERFORMANCE FOR D
Page 12 and 13: t RSTReset Reset RemovalV DD2.4V/ma
Page 14 and 15: LRCK50% of V DDt BCH t BCL t LBBCK5
Page 16 and 17: MODE CONTROL REGISTERSUser-Programm
Page 18 and 19: REGISTER 18 (Cont.)FMT[2:0] Audio I
Page 20 and 21: REGISTER 19 (Cont.)FLTDigital Filte
Page 24 and 25: APPLICATION FOR EXTERNAL DIGITAL FI
Page 26 and 27: APPLICATION FOR DSD FORMAT (DSD MOD
Page 28 and 29: APPLICATION FOR MONAURAL MODE OPERA
Page 30 and 31: CONSIDERATIONS FORAPPLICATIONS CIRC
Page 32: IMPORTANT NOTICETexas Instruments a

Burr Brown PCM1738 - 24-Bit, 192kHz Sampling.pdf - MaxDat

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