• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 30 subscribers
  • Views 922 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Two PCM3168A in TDM mode

Beni Raas
Prodigy 20 points
Other Parts Discussed in Thread: PCM3168A, PCM1864, PCM1690

Hi

I have an application where I need a codec with 8 ADC's and 8 DAC's. The digital signal is transmitted/received to/from the processor via two (one Tx, one Rx) TDM streams with 256 bits per frame. ADC and DAC resolution should be 16 bit with a sampling rate of 48000. I've been looking at using two PCM3168A codec, but can't quite figure out on how to setup it up so that I've got 4 ADC's from codec A and 4 ADC's from codec B into one stream and the same setup for the DAC's.

The codec also needs an I2c interface for control.

Is this achievable with the PCM3168A or does TI have another codec that will do this?


Regards
Beni

  • 0
    TI__Mastermind 28020 points
    Hi Beni,

    After looking through the data sheet, I don't believe the PCM3168A has the ability to output just 4 channels of the ADC to be able to use 2 devices with 4 channels each for your design. In response to that, I believe that 2 PCM1864's and one PCM1960 would be a good solution for your system. The two PCM1864 devices can do 4 channels each and will leave the other 4 slots HIZ so they can both talk on the same TDM bus. The PCM1690 has 8 DACs and can do 8 channel TDM in.

    Justin
  • 0 in reply to Justin Bohr
    Prodigy 20 points

    Hi Justin

    Thanks for the reply. I've looked at these two devices and put together a rough guide. Is this correct?

    PCM1864 ADC
    Pin 26 I2c        Gnd
    Pin 25 I2c (Chip A)    Gnd
    Pin 25 I2c (Chip B)    3V3
    Pin 24 I2c        SCL
    Pin 23 I2c        SDA
    Pin 22 floating
    Pin 21 floating
    Pin 20 floating
    Pin 19 floating
    Pin 18 DOUT        8 slot 32 bit output
    Pin 17 BCK in        Apply 12.288MHz
    Pin 16 LRCK        Apply Start of frame (256fs)
    Pin 15 SCKI in        Apply 12.288MHz
    Pin 10 floating
    Pin 9 floating
    Power as DS/figure 53
    1-4, 27-30        Analog inputs

    Has the ADC got a Reset pin?

    Reg 11        1101 1111
    Reg 12        0000 0001
    Reg 13        0000 0000    Chip A
    Reg 13        1000 0000    Chip B
    Reg 14        0000 0000    Chip A
    Reg 14        1000 0000    Chip B

    Reg 22-24    0010 1000

    Reg 32        0100 0000
    Reg 33        0000 0000
    Reg 34        0000 0000
    Reg 35        0000 0000
    Reg 36        0000 0000
    Reg 37        0000 0000
    Reg 38        0000 0000
    Reg 39        1111 1111
    Reg 40        0000 0000
    Reg 41        0000 0000
    Reg 42        0000 0000
    Reg 43        0000 0000
    Reg 44        0000 0000
    Reg 45        0000 0000
    Reg 48        0000 0000
    Reg 49        0000 0000
    Reg 50        0000 0000
    Reg 52        0000 0000
    Reg 53        0000 0000
    Reg 54        0000 0000
    Reg 50        0000 0000


    PCM1690 DAC
    Pin x RSV1        floating
    Pin x RSV2        Gnd
    Pin 6 LRCK        Apply Start of frame (256fs)
    Pin 7 BCK in        Apply 12.288MHz
    Pin 8 DIN1        8 slot 32 bit input
    Pin 9 DIN2        floating
    Pin 10 DIN3        floating
    Pin 11 DIN4        floating
    Pin 14 SCKI in        Apply 12.288MHz
    Pin 15 Rst        Reset
    Pin 16 ZERO1        not used
    Pin 17 ZERO2        not used
    Pin 18 AMUTEI        3V3
    Pin 19 AMUTEO        not used
    Pin 20 I2c        SDA
    Pin 21 I2c        SCL
    Pin 22 I2c        Gnd
    Pin 23 I2c        Gnd
    Pin 24 I2c        10k to Gnd


    Reg 64        0000 0011
    Reg 65        0000 0111
    Reg 66        0000 0000
    Reg 67        0000 0000
    Reg 68        0000 0000
    Reg 70        0000 0000
    Reg 72-79    1111 1111

    The datasheet for DAC recommends 5V for the Analog supply. I've got 3.3V only. However I don't need any high gain. Is that ok?

    Regards

    Beni