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TAS6424L-Q1: Can I make all 4 channels play either the L audio or R audio of the I2S data stream?

Carl Cowley
Prodigy 30 points
Part Number: TAS6424L-Q1

Hi,

First time with a project using I2S. I need to be able to use the chip with I2S and have all the channels play either the Left audio or the Right audio. Is this possible? I have poured over the data sheet and register settings, but I can't seem to find a way to tell it which channel of the I2S data to play on each of the 4 outputs of the chip. It appears to me that I can send it one data stream and it will play back, lets say the left audio, on outputs 1 &2 and the right audio on outputs 3 & 4, but there isn't a way to make it play just the left audio on outputs 1, 2, 3, and 4. Am I missing something?

The audio file I will be using is stereo, but I need all four of the channels of the one TAS6424L-Q1 to play only one side of the stereo channel. I realize the simple answer would be to make both of the stereo tracks the same, but I actually need them to be different as I will be having another amplifier using the other channel for a single speaker and line-out outputs.

Thanks in advance for any help you can provide!

  • 0
    TI__Expert 6985 points
    Hello Carl! This is possible, but it would have to be controlled through your DSP while using TDM format. Do you have access to program/control the DSP? Gregg can answer further questions. Thanks, Jeff
  • 0 in reply to Jeff Kohnle
    TI__Mastermind 45085 points
    Hi Carl,
    There is two ways to get the same signal on all four channels.
    1. Use i2S signals, with the same signal on the "L" and the "R" channels of the I2S data stream. Connect this stream to the SDIN1 and SDIN2 pins.
    2. Use TDM and place the same signal in all the channel slots. Connect this to the SDIN1 pin.
    The proper MCLK, SLCK, and FSYNC will be needed for each method.

    The TAS6424L-Q1 by itself cannot send one signal to all four channels.
  • 0 in reply to Jeff Kohnle
    Prodigy 30 points

    Thanks for the reply! I will look into the possibility of using TDM. The uP that I was planning on using has an I2S module built in, so I was hoping to use that to make the software side of things a bit easier. I may be making this too hard! I plan on using two chips anyway and from the data sheet it looks like it is possible to have eight outputs from an I2S connection to two TAS6424L-Q1. If that is correct, then I would be able to pull 2 outputs from each TAS6424L-Q1 for the four I need for one channel of the stereo signal. Is that correct?

    The data sheet shows an I2S system which drives two TAS6424L-Q1 chips. It shows the SOC connects DATA1 and DATA2 to the SDIN1 and SDIN2 of one TAS6424L-Q1 and DATA3 and DATA4 to the other TAS6424L-Q1 SDIN1 and SDIN2. Is it possible to drive all of the SDIN inputs from one DATA line? Would that provide me with 4 Left channel outputs and 4 Right channel outputs or am I not understanding the I2S protocol correctly?

    Thanks!

  • 0 in reply to Gregg Scott
    Prodigy 30 points
    Thanks for the reply! I think it is starting to gel in mind as to how the chip and I2S works. Please take a look at the reply I gave to Jeff Kohnle's reply to make sure I am understanding things correctly. If it works the way I have outlined, then this chip should be the answer I have been looking for to complete the next generation of our product. It has every feature I have been looking for. Thanks again!
  • 0 in reply to Carl Cowley
    TI__Mastermind 45085 points

    Hi Carl,

    If you run L on channels 1 an 3 of each device and R on channels 2 and 4 on each device, this will give you what you need using the standard I2S signal.  For the SDIN connections, connect SDIN1 and SDIN2 together on each device an connect this combination together.  I think the solution is easy.