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PGA2320: PGA2320

Richard Karwoski
Prodigy 10 points
Part Number: PGA2320
Other Parts Discussed in Thread: PGA2311,

The PGA 2320 Dec 2004, data sheet provides no detail on how/when the 16-bit serial register contents are transferred to the gain switch 'holding register' under basic operating conditions - specifically zero crossing disabled.

I would like to talk to an engineer who is familiar with this part .

Thank you.

  • 0
    TI__Guru 54306 points
    Hi Richard,

    On the PGA2311, which is a pin compatible device from the same family, the new gain settings take effect once CS goes high (when the zero crossing is disabled).

    Please let me know if you have additional questions, and/or if you need me to contact you directly. I am out of office on business travel this week but could have a discussion early next week.

    Many Thanks,

    Kind Regards,
    Luis
  • 0
    Genius 3945 points
    Hi, Richard,

    I have done some tests with this part, and with the zero-crossing detect disabled, the update happens pretty much immediately with the rising edge of the chip select. That's what one would expect for standard SPI.

    The test I did was to set the gain register to something rather low and feed in a tone. Monitor the output on one channel of your oscilloscope, and monitor the chip select on the other. Trigger on the rising edge of chip select. Then load in much higher gain setting, and you'll see exactly when the gain update occurs. Do the same with zero-crossing enabled.

    All that said, I haven't seen a reason to disable the zero-crossing detection, and with the PGA2320 controlling studio monitors the chip changes gain absolutely silently.
  • 0 in reply to Luis Chioye
    TI__Guru 54306 points
    I will continue this conversation through a conference call/direct email.

    Thank you,
    Best Regards,

    Luis