Synchronizing sound recorder/playback chips?

Lets say, I use several ICs of type ISD2500, and they all play the same song. How can I make sure they all play exactly at the same speed? Can this be controlled through pin "XCLK", and how?

Or are there sound chips that can specifically be synchronised?

2 Answers

  • 1 decade ago
    Favorite Answer

    It would certainly help if all of your ICs were tied to the same oscillator or crystal.

    What is the crystal speed? If it's in the kilohertz then using the same crystal is going to be more important, if it's in the Megahertz for a few second recording it's not going to make an audible difference.

    From an initial view of the product brief it would seem that starting them at the same time would be more important and that could be controlled by triggering the "playback" switch simultaneously.

    Source(s): Circuit designer
  • 1 decade ago

    I assume you have a datasheet. I've linked another one below. On page six it says, about timing, "If greater precision is

    required, the device can be clocked through the

    XCLK pin as follows: [...]"

    All you have to do is put an oscillating input into that terminal, assuming you've got a good rest-of-the-circuit. Using the same clock on all chips will assure they stay at the same speed.

    Not sure why you'd need to do that, though, unless you're pre-programming them and can't let them get even a little out of tune from each other. Or you want it perfect.

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